Pregnancy outcomes of immigrant women living in Korea: A population-based study

Geum Joon Cho; Ho Yeon Kim; Hyun Sun Ko; Hae Joong Cho; Seong Yeon Hong; Eunjin Noh; Young Ju Jeong

doi:10.1371/journal.pone.0278193

Peer Review History

Original SubmissionMarch 2, 2021
3 Sep 2021 Decision Letter - Rubeena Zakar, Editor PONE-D-21-06981 Pregnancy outcomes of immigrant women living in Korea: A population-based study PLOS ONE Dear Dr. Jeong, Thank you for submitting your manuscript to PLOS ONE. After careful consideration, we feel that it has merit but does not fully meet PLOS ONE’s publication criteria as it currently stands. Therefore, we invite you to submit a revised version of the manuscript that addresses the points raised during the review process. Please submit your revised manuscript by 10th October 2021. If you will need more time than this to complete your revisions, please reply to this message or contact the journal office at plosone@plos.org. When you're ready to submit your revision, log on to https://www.editorialmanager.com/pone/ and select the 'Submissions Needing Revision' folder to locate your manuscript file. Please include the following items when submitting your revised manuscript: A rebuttal letter that responds to each point raised by the academic editor and reviewer(s). You should upload this letter as a separate file labeled 'Response to Reviewers'. A marked-up copy of your manuscript that highlights changes made to the original version. You should upload this as a separate file labeled 'Revised Manuscript with Track Changes'. An unmarked version of your revised paper without tracked changes. You should upload this as a separate file labeled 'Manuscript'. If you would like to make changes to your financial disclosure, please include your updated statement in your cover letter. Guidelines for resubmitting your figure files are available below the reviewer comments at the end of this letter. If applicable, we recommend that you deposit your laboratory protocols in protocols.io to enhance the reproducibility of your results. Protocols.io assigns your protocol its own identifier (DOI) so that it can be cited independently in the future. For instructions see: http://journals.plos.org/plosone/s/submission-guidelines#loc-laboratory-protocols. Additionally, PLOS ONE offers an option for publishing peer-reviewed Lab Protocol articles, which describe protocols hosted on protocols.io. Read more information on sharing protocols at https://plos.org/protocols?utm_medium=editorial-email&utm_source=authorletters&utm_campaign=protocols. We look forward to receiving your revised manuscript. Kind regards, Rubeena Zakar, Ph.D Academic Editor PLOS ONE Journal Requirements: When submitting your revision, we need you to address these additional requirements. 1. Please ensure that your manuscript meets PLOS ONE's style requirements, including those for file naming. The PLOS ONE style templates can be found at https://journals.plos.org/plosone/s/file?id=wjVg/PLOSOne_formatting_sample_main_body.pdf and https://journals.plos.org/plosone/s/file?id=ba62/PLOSOne_formatting_sample_title_authors_affiliations.pdf. 2. PLOS requires an ORCID iD for the corresponding author in Editorial Manager on papers submitted after December 6th, 2016. Please ensure that you have an ORCID iD and that it is validated in Editorial Manager. To do this, go to ‘Update my Information’ (in the upper left-hand corner of the main menu), and click on the Fetch/Validate link next to the ORCID field. This will take you to the ORCID site and allow you to create a new iD or authenticate a pre-existing iD in Editorial Manager. Please see the following video for instructions on linking an ORCID iD to your Editorial Manager account: https://www.youtube.com/watch?v=_xcclfuvtxQ. 3. Your ethics statement should only appear in the Methods section of your manuscript. If your ethics statement is written in any section besides the Methods, please move it to the Methods section and delete it from any other section. Please ensure that your ethics statement is included in your manuscript, as the ethics statement entered into the online submission form will not be published alongside your manuscript. [Note: HTML markup is below. Please do not edit.] Reviewers' comments: Reviewer's Responses to Questions Comments to the Author 1. Is the manuscript technically sound, and do the data support the conclusions? The manuscript must describe a technically sound piece of scientific research with data that supports the conclusions. Experiments must have been conducted rigorously, with appropriate controls, replication, and sample sizes. The conclusions must be drawn appropriately based on the data presented. Reviewer #1: Partly Reviewer #2: Yes ******** 2. Has the statistical analysis been performed appropriately and rigorously? Reviewer #1: Yes Reviewer #2: Yes ****** 3. Have the authors made all data underlying the findings in their manuscript fully available? The PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception (please refer to the Data Availability Statement in the manuscript PDF file). The data should be provided as part of the manuscript or its supporting information, or deposited to a public repository. For example, in addition to summary statistics, the data points behind means, medians and variance measures should be available. If there are restrictions on publicly sharing data—e.g. participant privacy or use of data from a third party—those must be specified. Reviewer #1: No Reviewer #2: No ****** 4. Is the manuscript presented in an intelligible fashion and written in standard English? PLOS ONE does not copyedit accepted manuscripts, so the language in submitted articles must be clear, correct, and unambiguous. Any typographical or grammatical errors should be corrected at revision, so please note any specific errors here. Reviewer #1: Yes Reviewer #2: Yes ****** 5. Review Comments to the Author Please use the space provided to explain your answers to the questions above. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. (Please upload your review as an attachment if it exceeds 20,000 characters) Reviewer #1: This article addresses an actual problem: the pregnancy outcomes among immigrant women in Korea. There are a number of issues with the methods and analysis that need to be clarified/addressed. Below are more specific comments by section: Abstract: Since you are calculating the OR, you should consider replacing “risk” by “odds”. Introduction I do not see what does the information about interracial marriages adds in the section. The authors take a rather narrow view of data publication, Materials & Methods / Datasets and outcomes You are not describing from where you are taking the variable age from. Results section This section needs to be improved. The variables selected for describing the study population are not exhaustive. If available, authors could also present information on employment status and educational level, previous c-section, Hypertension. Diabetes, for basic characteristics and potential risk factors. If you do not have information on these previous risk factors, you might want to mention it as a limitation. Information regarding the % of missing data on each variable (you refer to this in the discussion section) could be useful Table 1 includes information about outcomes that shouldn’t be described here. (GBD, preeclampsia. CS, induction etc) When describing table 2 authors should refer as odds in state of risk. You might want to include information on low birth weigh and/or preterm birth since part of your background information includes those outcomes. Discussion section The first paragraph is confusing. Which are you main findings? Line 179. You are including new information (birthweight) that was not mention on the results section. Try to stress what your data adds to the existing body of evidence Reviewer #2: The authors made a great presentation of the study findings - clearly linking the problem, aims, research questions, methodology, analysis results/findings, discussions, conclusions, and recommendations. Also, study clearly demonstrated associating factors with pregnancy outcomes in both groups. However, authors could provide more details in explanation to help the audience understand how caesarean section rate affects pregnancy outcome among immigrant women and state which specific cofounding factors affected (increased) caesarean section among immigrant women [line 176 & 177]. Over all, I think this is a technically sound and well documented study with details clearly stated findings and recommendations. Authors should state in the conclusion who (government, health workers, policy makers,…) is responsible for implementing effective pregnancy and postpartum management change/intervention for immigrant women [line 206 & 207] to enhance social change. ****** 6. PLOS authors have the option to publish the peer review history of their article (what does this mean?). If published, this will include your full peer review and any attached files. If you choose “no”, your identity will remain anonymous but your review may still be made public. Do you want your identity to be public for this peer review? For information about this choice, including consent withdrawal, please see our Privacy Policy. Reviewer #1: No Reviewer #2: Yes:** Gabriel Adebe PhD [NOTE: If reviewer comments were submitted as an attachment file, they will be attached to this email and accessible via the submission site. Please log into your account, locate the manuscript record, and check for the action link "View Attachments". If this link does not appear, there are no attachment files.] While revising your submission, please upload your figure files to the Preflight Analysis and Conversion Engine (PACE) digital diagnostic tool, https://pacev2.apexcovantage.com/. PACE helps ensure that figures meet PLOS requirements. To use PACE, you must first register as a user. Registration is free. Then, login and navigate to the UPLOAD tab, where you will find detailed instructions on how to use the tool. If you encounter any issues or have any questions when using PACE, please email PLOS at figures@plos.org. Please note that Supporting Information files do not need this step. Attachments Attachment Submitted filename: PLOSONE2021.docx https://doi.org/10.1371/journal.pone.0278193.r001
Revision 1
23 Dec 2021 Author Response Reviewer #1: This article addresses an actual problem: the pregnancy outcomes among immigrant women in Korea. There are a number of issues with the methods and analysis that need to be clarified/addressed. Below are more specific comments by section: Abstract: Since you are calculating the OR, you should consider replacing “risk” by “odds”. Response: As you have pointed out, we wrote “odds” instead of “risk” as suggested. Introduction I do not see what does the information about interracial marriages adds in the section. The authors take a rather narrow view of data publication, Response: We fully agree with your suggestion. We corrected the introduction as follows (Line 65-75) Preterm birth and low birth weight are serious adverse pregnancy outcomes. They are not only related to infant morbidity and mortality but also increase risk for chronic diseases such as cardiovascular diseases and metabolic syndrome during lifetime[1]. Several biological risk factors have been identified such as maternal age, body mass index and smoking and alcohol consumption. Further influences of racial and ethnic disparities have been documented. Although, many obstetric investigations across different countries have limited adjustment for ethnicity, compared to native women, immigrant women have an increased risk of preterm birth, low birth weight and cesarean section.[1,2, 4,5] It has been reported that immigrants in countries of resettlement have a greater risk of gestational diabetes mellitus (GDM) than women in receiving countries.[3] Thus, influxes of migrant women of childbearing age to receiving countries have made their perinatal health status a key priority for many governments.[5] Materials & Methods / Datasets and outcomes You are not describing from where you are taking the variable age from. Response: We added “HIRA” in this sentence (Line 94-95) as following: “The HIRA database we received included unidentifiable codes that represented individuals, together with age, diagnosis, and a list of prescribed procedures.” Results section This section needs to be improved. The variables selected for describing the study population are not exhaustive. If available, authors could also present information on employment status and educational level, previous c-section, Hypertension. Diabetes, for basic characteristics and potential risk factors. If you do not have information on these previous risk factors, you might want to mention it as a limitation. Response: We included limited information obtained from HIRA database and wrote limitation of certain risk factors (Line 201-205) in discussion. “Second, although the HIRA database comprises representative data of the whole country, it lacks information on uninsured medical claims, employment status, educational level as well as clinical information before the period we studied. In particular, migrant women do not know their past history in their previous country. ” Information regarding the % of missing data on each variable (you refer to this in the discussion section) could be useful Response: The strength of our study is that there is no missing data in HIRA database. We added this comment on page 13, line 206-207. Table 1 includes information about outcomes that shouldn’t be described here. (GBD, preeclampsia. CS, induction etc) Response: We reorganized table 1 into table 1 which includes basic characteristics and table 2 which includes pregnancy outcome. When describing table 2 authors should refer as odds in state of risk. You might want to include information on low birth weigh and/or preterm birth since part of your background information includes those outcomes. Response: We changed the risk to odds in Line 134-142. Discussion section The first paragraph is confusing. Which are you main findings? Response: We clarified the first paragraph of discussion as follows. “Immigrant women had a lower prevalence of preeclampsia and PPH and higher prevalence of GDM, CS and placenta previa compared to Korean women after adjustment for age, parity, and CCI.” Line 179. You are including new information (birthweight) that was not mention on the results section. Response: We deleted this irrelevant sentence. “In line with this, we previously reported that the birthweight was lower for the children of foreign women than for those of Korean women.” Try to stress what your data adds to the existing body of evidence Response: Our study with large population data demonstrated different pregnancy outcomes of immigrant women. Increased risk of GDM, CS and placenta previa were showed after adjusting maternal age, parity and CCI. This result will help clinicians to consider different pregnancy outcomes when they meet immigrant women. Eventually, predicting and preparing for adverse pregnancy outcome in advance will contribute to improving pregnancy outcomes. Reviewer #2: The authors made a great presentation of the study findings - clearly linking the problem, aims, research questions, methodology, analysis results/findings, discussions, conclusions, and recommendations. Also, study clearly demonstrated associating factors with pregnancy outcomes in both groups. However, authors could provide more details in explanation to help the audience understand how caesarean section rate affects pregnancy outcome among immigrant women and state which specific cofounding factors affected (increased) caesarean section among immigrant women [line 176 & 177]. Response: We added following statement in Line 176-179. “In this study, the cesarean section rate was lower in immigrant women than in Korean women, but after adjustment for age, parity and CCI, the risk for cesarean section was higher in immigrant women. Immigrant women were younger than Korean women therefore age might be a factor which influences the lower rate of CS before adjustment.” Over all, I think this is a technically sound and well documented study with details clearly stated findings and recommendations. Authors should state in the conclusion who (government, health workers, policy makers,…) is responsible for implementing effective pregnancy and postpartum management change/intervention for immigrant women [line 206 & 207] to enhance social change. Response: We added following statement in the last paragraph of this manuscript(Line 207-209). “These characteristics should be reflected in Korean medical system to enhance social changes and effective pregnancy and postpartum management by healthcare providers will be necessary for immigrant women.” Attachments Attachment Submitted filename: response to reviewer plos one.docx https://doi.org/10.1371/journal.pone.0278193.r002
28 Mar 2022 Decision Letter - Rubeena Zakar, Editor PONE-D-21-06981R1Pregnancy outcomes of immigrant women living in Korea: A population-based studyPLOS ONE Dear Dr. Ju Jeong Thank you for submitting your manuscript to PLOS ONE. After careful consideration, we feel that it has merit but does not fully meet PLOS ONE’s publication criteria as it currently stands. Therefore, we invite you to submit a revised version of the manuscript that addresses the points raised during the review process. Please submit your revised manuscript by 12th May 2022. If you will need more time than this to complete your revisions, please reply to this message or contact the journal office at plosone@plos.org. When you're ready to submit your revision, log on to https://www.editorialmanager.com/pone/ and select the 'Submissions Needing Revision' folder to locate your manuscript file. Please include the following items when submitting your revised manuscript: A rebuttal letter that responds to each point raised by the academic editor and reviewer(s). You should upload this letter as a separate file labeled 'Response to Reviewers'. A marked-up copy of your manuscript that highlights changes made to the original version. You should upload this as a separate file labeled 'Revised Manuscript with Track Changes'. An unmarked version of your revised paper without tracked changes. You should upload this as a separate file labeled 'Manuscript'. If you would like to make changes to your financial disclosure, please include your updated statement in your cover letter. Guidelines for resubmitting your figure files are available below the reviewer comments at the end of this letter. If applicable, we recommend that you deposit your laboratory protocols in protocols.io to enhance the reproducibility of your results. Protocols.io assigns your protocol its own identifier (DOI) so that it can be cited independently in the future. For instructions see: https://journals.plos.org/plosone/s/submission-guidelines#loc-laboratory-protocols. Additionally, PLOS ONE offers an option for publishing peer-reviewed Lab Protocol articles, which describe protocols hosted on protocols.io. Read more information on sharing protocols at https://plos.org/protocols?utm_medium=editorial-email&utm_source=authorletters&utm_campaign=protocols. We look forward to receiving your revised manuscript. Kind regards, Rubeena Zakar, Ph.D Academic Editor PLOS ONE Journal Requirements: Please review your reference list to ensure that it is complete and correct. If you have cited papers that have been retracted, please include the rationale for doing so in the manuscript text, or remove these references and replace them with relevant current references. Any changes to the reference list should be mentioned in the rebuttal letter that accompanies your revised manuscript. If you need to cite a retracted article, indicate the article’s retracted status in the References list and also include a citation and full reference for the retraction notice. [Note: HTML markup is below. Please do not edit.] Reviewers' comments: Reviewer's Responses to Questions Comments to the Author 1. If the authors have adequately addressed your comments raised in a previous round of review and you feel that this manuscript is now acceptable for publication, you may indicate that here to bypass the “Comments to the Author” section, enter your conflict of interest statement in the “Confidential to Editor” section, and submit your "Accept" recommendation. Reviewer #1: (No Response) Reviewer #2: All comments have been addressed ******** 2. Is the manuscript technically sound, and do the data support the conclusions? The manuscript must describe a technically sound piece of scientific research with data that supports the conclusions. Experiments must have been conducted rigorously, with appropriate controls, replication, and sample sizes. The conclusions must be drawn appropriately based on the data presented. Reviewer #1: Partly Reviewer #2: Yes ****** 3. Has the statistical analysis been performed appropriately and rigorously? Reviewer #1: Yes Reviewer #2: Yes ****** 4. Have the authors made all data underlying the findings in their manuscript fully available? The PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception (please refer to the Data Availability Statement in the manuscript PDF file). The data should be provided as part of the manuscript or its supporting information, or deposited to a public repository. For example, in addition to summary statistics, the data points behind means, medians and variance measures should be available. If there are restrictions on publicly sharing data—e.g. participant privacy or use of data from a third party—those must be specified. Reviewer #1: Yes Reviewer #2: Yes ****** 5. Is the manuscript presented in an intelligible fashion and written in standard English? PLOS ONE does not copyedit accepted manuscripts, so the language in submitted articles must be clear, correct, and unambiguous. Any typographical or grammatical errors should be corrected at revision, so please note any specific errors here. Reviewer #1: No Reviewer #2: Yes ****** 6. Review Comments to the Author Please use the space provided to explain your answers to the questions above. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. (Please upload your review as an attachment if it exceeds 20,000 characters) Reviewer #1: The paper needs language editing. Consider a language revision. When explaining The Charlson Comorbidity Index it would be useful to explain if the higher the score the more comorbid conditions are present (line 110) From line 135 to 140 you described table 1, but in the middle of the paragraph there is information related to table 2 (The cesarean section (CS) rate was lower in foreign women than Korean women. The incidence of placental abruption, placental previa, PPH, PH, and UAE were lower in immigrant women than Korean women.) that information was repeated in line 150. Table 2. you included: Values are expressed as mean (SD) or %. But there are not values expressed as mean and SD Table 3. should be named: Odds ratio and 95% confidence intervals of adverse pregnancy out 155 comes of immigrant women instead of Odds ratio and 95% confidence intervals of the risk of adverse pregnancy out 155 comes of immigrant women This sentence is confusing: In particular, migrant women do not know their past history in their previous country Which is their past history they don’t know? In table 1 it says “Primparity” check spelling Line 187: it says risks, it should say odds 190. I still see the sentences: In line with this, we previously reported that the birthweight was lower for the children of foreign women than for those of Korean women.[11] In this sense: I asked you before, Try to stress what your data adds to the existing body of evidence Your Response was: “Our study with large population data demonstrated different pregnancy outcomes of immigrant women. Increased risk of GDM, CS and placenta previa were showed after adjusting maternal age, parity and CCI. This result will help clinicians to consider different pregnancy outcomes when they meet immigrant women. Eventually, predicting and preparing for adverse pregnancy outcome in advance will contribute to improving pregnancy outcomes.” That information was not included in the discussion section. Besides, there was not an increased risk of placenta previa (the confidence interval starts in1) I think you should do emphasis on the results presented in table 3.: After adjusting by age, parity and CCI, which are the variables you are expected to adjust by, (considering there were differences between the 2 groups in table 1). Findings are that: to be immigrant increase the risk of having GDM, and CS. But protects against having preeclampsia, and induction. Reviewer #2: Earlier concerns addressed, paper appears consistent with sections observed with minor changes. I believe the paper is publish-ready ****** 7. PLOS authors have the option to publish the peer review history of their article (what does this mean?). If published, this will include your full peer review and any attached files. If you choose “no”, your identity will remain anonymous but your review may still be made public. Do you want your identity to be public for this peer review? For information about this choice, including consent withdrawal, please see our Privacy Policy. Reviewer #1: No Reviewer #2: Yes:** Adebe Gabriel Aondofa (Ph.D, MPH) [NOTE: If reviewer comments were submitted as an attachment file, they will be attached to this email and accessible via the submission site. Please log into your account, locate the manuscript record, and check for the action link "View Attachments". If this link does not appear, there are no attachment files.] While revising your submission, please upload your figure files to the Preflight Analysis and Conversion Engine (PACE) digital diagnostic tool, https://pacev2.apexcovantage.com/. PACE helps ensure that figures meet PLOS requirements. To use PACE, you must first register as a user. Registration is free. Then, login and navigate to the UPLOAD tab, where you will find detailed instructions on how to use the tool. If you encounter any issues or have any questions when using PACE, please email PLOS at figures@plos.org. Please note that Supporting Information files do not need this step. Attachments Attachment Submitted filename: koren and inmigrants_2nd.docx https://doi.org/10.1371/journal.pone.0278193.r003
Revision 2
25 Apr 2022 Author Response Reviewer #1: The paper needs language editing. Consider a language revision. : We finished language editing as suggested. When explaining The Charlson Comorbidity Index it would be useful to explain if the higher the score the more comorbid conditions are present (line 110) : We added this statement in line 112 “that the higher the score the more comorbid conditions are present’ From line 135 to 140 you described table 1, but in the middle of the paragraph there is information related to table 2 (The cesarean section (CS) rate was lower in foreign women than Korean women. The incidence of placental abruption, placental previa, PPH, PH, and UAE were lower in immigrant women than Korean women.) that information was repeated in line 150. :We deleted this sentence in line 130. Table 2. you included: Values are expressed as mean (SD) or %. But there are not values expressed as mean and SD : We wrote “values are expressed as number, %.” Table 3. should be named: Odds ratio and 95% confidence intervals of adverse pregnancy out 155 comes of immigrant women instead of Odds ratio and 95% confidence intervals of the risk of adverse pregnancy out 155 comes of immigrant women : We corrected as suggested. This sentence is confusing: In particular, migrant women do not know their past history in their previous country Which is their past history they don’t know? : We corrected this sentence as follows; In particular it was difficult to obtain previous medical histories of migrant women in their previous country. In table 1 it says “Primparity” check spelling : We corrected as suggested Line 187: it says risks, it should say odds 190. : We corrected as suggested I still see the sentences: In line with this, we previously reported that the birthweight was lower for the children of foreign women than for those of Korean women.[11] : We deleted this sentence as suggested. In this sense: I asked you before, Try to stress what your data adds to the existing body of evidence Your Response was: “Our study with large population data demonstrated different pregnancy outcomes of immigrant women. Increased risk of GDM, CS and placenta previa were showed after adjusting maternal age, parity and CCI. This result will help clinicians to consider different pregnancy outcomes when they meet immigrant women. Eventually, predicting and preparing for adverse pregnancy outcome in advance will contribute to improving pregnancy outcomes.” That information was not included in the discussion section. Besides, there was not an increased risk of placenta previa (the confidence interval starts in1) : We added this sentences in discussion section. The risk of placenta previa was corrected in abstract, results and discussion. I think you should do emphasis on the results presented in table 3.: After adjusting by age, parity and CCI, which are the variables you are expected to adjust by, (considering there were differences between the 2 groups in table 1). Findings are that: to be immigrant increase the risk of having GDM, and CS. But protects against having preeclampsia, and induction. : We added following statement in the first paragraph of discussion (Line 166-168) Immigrant women were protected against having preeclampsia and PPH and higher risk of GDM and CS compared to Korean women after adjustment for age, parity and CCI. Attachments Attachment Submitted filename: Response to reviewers after 2nd.docx https://doi.org/10.1371/journal.pone.0278193.r004
10 Jul 2022 Decision Letter - Rubeena Zakar, Editor PONE-D-21-06981R2Pregnancy outcomes of immigrant women living in Korea: A population-based studyPLOS ONE Dear Dr. Ju Jeong, Thank you for submitting your manuscript to PLOS ONE. After careful consideration, we feel that it has merit but does not fully meet PLOS ONE’s publication criteria as it currently stands. Therefore, we invite you to submit a revised version of the manuscript that addresses the points raised during the review process. Please submit your revised manuscript by 24 August 2022 . If you will need more time than this to complete your revisions, please reply to this message or contact the journal office at plosone@plos.org. When you're ready to submit your revision, log on to https://www.editorialmanager.com/pone/ and select the 'Submissions Needing Revision' folder to locate your manuscript file. Please include the following items when submitting your revised manuscript: A rebuttal letter that responds to each point raised by the academic editor and reviewer(s). You should upload this letter as a separate file labeled 'Response to Reviewers'. A marked-up copy of your manuscript that highlights changes made to the original version. You should upload this as a separate file labeled 'Revised Manuscript with Track Changes'. An unmarked version of your revised paper without tracked changes. You should upload this as a separate file labeled 'Manuscript'. If you would like to make changes to your financial disclosure, please include your updated statement in your cover letter. Guidelines for resubmitting your figure files are available below the reviewer comments at the end of this letter. If applicable, we recommend that you deposit your laboratory protocols in protocols.io to enhance the reproducibility of your results. Protocols.io assigns your protocol its own identifier (DOI) so that it can be cited independently in the future. For instructions see: https://journals.plos.org/plosone/s/submission-guidelines#loc-laboratory-protocols. Additionally, PLOS ONE offers an option for publishing peer-reviewed Lab Protocol articles, which describe protocols hosted on protocols.io. Read more information on sharing protocols at https://plos.org/protocols?utm_medium=editorial-email&utm_source=authorletters&utm_campaign=protocols. We look forward to receiving your revised manuscript. Kind regards, Rubeena Zakar, Ph.D Section Editor PLOS ONE [Note: HTML markup is below. Please do not edit.] Reviewers' comments: Reviewer's Responses to Questions Comments to the Author 1. If the authors have adequately addressed your comments raised in a previous round of review and you feel that this manuscript is now acceptable for publication, you may indicate that here to bypass the “Comments to the Author” section, enter your conflict of interest statement in the “Confidential to Editor” section, and submit your "Accept" recommendation. Reviewer #1: All comments have been addressed Reviewer #3: (No Response) Reviewer #4: (No Response) ******** 2. Is the manuscript technically sound, and do the data support the conclusions? The manuscript must describe a technically sound piece of scientific research with data that supports the conclusions. Experiments must have been conducted rigorously, with appropriate controls, replication, and sample sizes. The conclusions must be drawn appropriately based on the data presented. Reviewer #1: Yes Reviewer #3: Yes Reviewer #4: Partly ****** 3. Has the statistical analysis been performed appropriately and rigorously? Reviewer #1: Yes Reviewer #3: Yes Reviewer #4: No ****** 4. Have the authors made all data underlying the findings in their manuscript fully available? The PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception (please refer to the Data Availability Statement in the manuscript PDF file). The data should be provided as part of the manuscript or its supporting information, or deposited to a public repository. For example, in addition to summary statistics, the data points behind means, medians and variance measures should be available. If there are restrictions on publicly sharing data—e.g. participant privacy or use of data from a third party—those must be specified. Reviewer #1: Yes Reviewer #3: No Reviewer #4: Yes ****** 5. Is the manuscript presented in an intelligible fashion and written in standard English? PLOS ONE does not copyedit accepted manuscripts, so the language in submitted articles must be clear, correct, and unambiguous. Any typographical or grammatical errors should be corrected at revision, so please note any specific errors here. Reviewer #1: Yes Reviewer #3: Yes Reviewer #4: Yes ****** 6. Review Comments to the Author Please use the space provided to explain your answers to the questions above. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. (Please upload your review as an attachment if it exceeds 20,000 characters) Reviewer #1: All my comments were addressed. Well done. I have no further comments. ........................................................... Reviewer #3: The authors have done well in providing evidence on pregnancy outcomes among immigrants in Korea. Authors could consider the following issues to strengthen the paper. Introduction Authors provide a very brief introduction to the topic of interest and seem to miss out important detail. First, about half of the first paragraph focuses on preterm birth and low birth weight and their predictors when the study itself (including analysis) rarely considers these outcomes. Second, the detail on interracial marriage in Korea is great to provide information on the immigration status in Korea. However, the argument is too one-sided and does not feed into the issues raised in the subsequent sentences. I think a reviewer in the earlier revisions of this work raised this issue. Authors could strengthen their introduction by considering the following: 1. What pregnancy outcomes are highly prevalent in Korea? 2. Are there studies that report on these outcomes by immigration status in Korea? Kindly report on this in addition to what has been done in other countries. 3. Justify why immigrants in Korea should be focused. Methods 1. Authors should provide justification for the duration 2007 - 2016. 2. Can authors clearly define their outcome variables? For instance a number of variables are mentioned and this includes parity and multiple pregnancies which i presume are not the main outcome variables of interest they seek to look at. 3. Regarding section titled "covariates", authors seem to focus mainly on ICC and how it is created from pre-pregnancy factors but there is no information on the specific factors that were combined to create this index. Neither is there information on how this index is created. Is this something that exist in the database or it is an index authors created themselves. Authors should kindly provide more detail regarding this. 4. Since the data for the study covers the period between 2007 and 2016, there is the possibility of multiple pregnancies per woman. How do authors account for this? 5. Line 118: can authors specify the exact group they are referring to? 6. Authors also do not mention the final sample size they used. 7. I think authors should dedicate a section for ethical consideration to outline all forms of ethics that apply to their work; data availability and how it was accessed. Results 1. lines 131-133: results is not in Table 1. Authors should check this and interpret the other variables in table one in place of this. Discussion I find the results to be well discussed and the limitations well laid out. Reviewer #4: I appreciate the opportunity to review your manuscript. Please find below some important areas in which the manuscript can be clarified or improved from the statistical perspective. 1) The methods section of the manuscript can be better organized by using sub headings e.g. study design and data source, study outcomes, other measures, etc. Please follow the CONSORT guidelines or any other required by the journal. 2) Primary and secondary outcomes must be clearly identified and distinguished in the abstract, methods section, statistical methods, results, and discussion. 3) Please mention all the covariates that were examined in the covariates section of the manuscript. 4) In the statistical analysis section, please include that model was run stepwise and reason behind running 3 separate models. 5) In all the tables in which statistical tests were conducted, the footnotes need to specify which test was used to derive each reported P-value. 6) For age please clarify in the tables if it is mean age or median. 7) Authors have multiple outcome variables but use 0.05 as significance criterion throughout. Please use Bonferroni correction or other method to adjust for multiple testing. Otherwise, the results will have an elevated chance of being false positives. 8) Was there any missing data in your study? How was it handled? ****** 7. PLOS authors have the option to publish the peer review history of their article (what does this mean?). If published, this will include your full peer review and any attached files. If you choose “no”, your identity will remain anonymous but your review may still be made public. Do you want your identity to be public for this peer review? For information about this choice, including consent withdrawal, please see our Privacy Policy. Reviewer #1: No Reviewer #3: No Reviewer #4: No ******** [NOTE: If reviewer comments were submitted as an attachment file, they will be attached to this email and accessible via the submission site. Please log into your account, locate the manuscript record, and check for the action link "View Attachments". If this link does not appear, there are no attachment files.] While revising your submission, please upload your figure files to the Preflight Analysis and Conversion Engine (PACE) digital diagnostic tool, https://pacev2.apexcovantage.com/. PACE helps ensure that figures meet PLOS requirements. To use PACE, you must first register as a user. Registration is free. Then, login and navigate to the UPLOAD tab, where you will find detailed instructions on how to use the tool. If you encounter any issues or have any questions when using PACE, please email PLOS at figures@plos.org. Please note that Supporting Information files do not need this step. https://doi.org/10.1371/journal.pone.0278193.r005
Revision 3
8 Sep 2022 Author Response Response to reviewers Reviewer #3: The authors have done well in providing evidence on pregnancy outcomes among immigrants in Korea. Authors could consider the following issues to strengthen the paper. Introduction Authors provide a very brief introduction to the topic of interest and seem to miss out important detail. First, about half of the first paragraph focuses on preterm birth and low birth weight and their predictors when the study itself (including analysis) rarely considers these outcomes. Second, the detail on interracial marriage in Korea is great to provide information on the immigration status in Korea. However, the argument is too one-sided and does not feed into the issues raised in the subsequent sentences. I think a reviewer in the earlier revisions of this work raised this issue. Authors could strengthen their introduction by considering the following: 1. What pregnancy outcomes are highly prevalent in Korea? � In South Korea, the incidence of GDM, hypertensive disorder in pregnancy, and preterm birth and the rate of cesarean section have been steadily increasing. GDM accounts for 15.8% in 2017 to 18.01% in 2021, preeclampsia has doubled 2.75% in 2017 to 5.34% in 2021, preterm birth rate was 5.8% in 2010 and 8.5% in 2020 2. Are there studies that report on these outcomes by immigration status in Korea? Kindly report on this in addition to what has been done in other countries. 3. Justify why immigrants in Korea should be focused. � We appreciate above suggestions mainly focusing on why we need to study immigrant pregnant women and their association with adverse pregnancy outcomes. Therefore we rewrote and organized introduction. Methods 1. Authors should pro vide justification for the duration 2007 - 2016. � At the time of planning the study, period between 2007 and 2016 could be accessed and analyzed. In the future, it is also necessary to use this data to see long-term changes. 2. Can authors clearly define their outcome variables? For instance a number of variables are mentioned and this includes parity and multiple pregnancies which i presume are not the main outcome variables of interest they seek to look at. � We defined variables we looked at as suggested in methods � Parity and the rate of cesarean section, induction, vacuum delivery, uterine arterial embolization (UAE), and peripartum hysterectomy (PH) were also identified using the presence of a Korea Medical Insurance electronic data interchange (EDI) code. 3. Regarding section titled "covariates", authors seem to focus mainly on ICC and how it is created from pre-pregnancy factors but there is no information on the specific factors that were combined to create this index. Neither is there information on how this index is created. Is this something that exist in the database or it is an index authors created themselves. Authors should kindly provide more detail regarding this. � CCI was used in this manuscript to represent comorbid status of patients before pregnancy as a simple and widely used method to identify underlying diseases. We added more detail and reference on CCI in the methods. �The CCI has been known to be a useful and most widely used tool to measure comorbid disease status including cardiovascular diseases, diabetes, malignancies and autoimmune diseases or casemix in health care databases that the higher the score the more comorbid conditions are present. Acute myocardial infarction, Congestive heart failure, Peripheral vascular disease, Cerebral vascular accident, Dementia, Pulmonary disease, Connective tissue disorder, Peptic ulcer, Liver disease, Diabetes, Diabetes complications, Paraplegia, Renal disease, Cancer, Metastatic cancer, Severe liver disease, HIV were analyzed in this study. 4. Since the data for the study covers the period between 2007 and 2016, there is the possibility of multiple pregnancies per woman. How do authors account for this? � Multiple pregnancies were included in this data set but we did not put as a variable. We also deleted “multiple pregnancy” in method section. 5. Line 118: can authors specify the exact group they are referring to? � We added following sentence to define group � (Line 130-131) The Student’s t-test was used to compare continuous variables between Korean and immigrant pregnant women 6. Authors also do not mention the final sample size they used. � Final sample size was 4,439,778. 7. I think authors should dedicate a section for ethical consideration to outline all forms of ethics that apply to their work; data availability and how it was accessed. � We added following statement in method. � Ethical consideration This study was approved by the Institutional Review Committees of Korea University Guro Hospital (KUGH17273). The informed consent was waived by this IRB because the HIRA database does not include individual identities and because of retrospective nature of this study. This study comprises of third-party data therefore authors cannot share data nor legally distribute. Results 1. lines 131-133: results is not in Table 1. Authors should check this and interpret the other variables in table one in place of this. � We corrected result of table 1 in manuscript. � Table 1 shows the basic characteristics of the study population according to maternal ethnicity. Foreign women were younger and more primiparous than Korean women and tended to have lower CCI score than Korean women. Discussion I find the results to be well discussed and the limitations well laid out. �We appreciate this comment. Reviewer #4: I appreciate the opportunity to review your manuscript. Please find below some important areas in which the manuscript can be clarified or improved from the statistical perspective. 1) The methods section of the manuscript can be better organized by using sub headings e.g. study design and data source, study outcomes, other measures, etc. Please follow the CONSORT guidelines or any other required by the journal. � We used following headings in methods. Study desing-data characteristics-Ethical consideration-Dataset and outcomes-Covariates-Statistical analysis 2) Primary and secondary outcomes must be clearly identified and distinguished in the abstract, methods section, statistical methods, results, and discussion. � We used ‘main outcome’ and added following sentence in the abstract, method, results and discussion. � Main outcome of this study were adverse pregnancy outcomes including GDM, preeclampsia, cesarean section, induction of labor, vacuum delivery, placenta previa, placenta abruption, PPH, peripartum hysterectomy and UAE. Age, parity and CCI were adjusted for multiple logistic regression analysis. 3) Please mention all the covariates that were examined in the covariates section of the manuscript. � CCI used in this study included following diseases. � Acute myocardial infarction, Congestive heart failure, Peripheral vascular disease, Cerebral vascular accident, Dementia, Pulmonary disease, Connective tissue disorder, Peptic ulcer, Liver disease, Diabetes, Diabetes complications, Paraplegia, Renal disease, Cancer, Metastatic cancer, Severe liver disease, HIV were analyzed in this study. 4) In the statistical analysis section, please include that model was run stepwise and reason behind running 3 separate models. �We added ‘the model was run stepwise’ in method. The running 3 separate models was conducted to identify the variables that affect the most. 5) In all the tables in which statistical tests were conducted, the footnotes need to specify which test was used to derive each reported P-value. � We added all the statistical tests used in the footnotes of each tables. 6) For age please clarify in the tables if it is mean age or median. � For age, the results indicate mean±standard deviation. 7) Authors have multiple outcome variables but use 0.05 as significance criterion throughout. Please use Bonferroni correction or other method to adjust for multiple testing. Otherwise, the results will have an elevated chance of being false positives. � We appreciate thorough statistical suggestions. In this study, multiple outcome variables were analyzed. Although each variable may be related to each other, each variable is an important subject identified in obstetrics. Therefore, age, parity, and CCI were adjusted in regression model. 8) Was there any missing data in your study? How was it handled? �This study is based on the claim data and since the diagnosis was confirmed using the icd-10 code, there is no missing data among the mothers charged for delivery. We added this issue in limitation of discussion. Attachments Attachment Submitted filename: Response to reviewers.docx https://doi.org/10.1371/journal.pone.0278193.r006
14 Nov 2022 Decision Letter - Rubeena Zakar, Editor Pregnancy outcomes of immigrant women living in Korea: A population-based study PONE-D-21-06981R3 Dear Dr. Jeong, We’re pleased to inform you that your manuscript has been judged scientifically suitable for publication and will be formally accepted for publication once it meets all outstanding technical requirements. Within one week, you’ll receive an e-mail detailing the required amendments. When these have been addressed, you’ll receive a formal acceptance letter and your manuscript will be scheduled for publication. An invoice for payment will follow shortly after the formal acceptance. To ensure an efficient process, please log into Editorial Manager at http://www.editorialmanager.com/pone/, click the 'Update My Information' link at the top of the page, and double check that your user information is up-to-date. If you have any billing related questions, please contact our Author Billing department directly at authorbilling@plos.org. If your institution or institutions have a press office, please notify them about your upcoming paper to help maximize its impact. If they’ll be preparing press materials, please inform our press team as soon as possible -- no later than 48 hours after receiving the formal acceptance. Your manuscript will remain under strict press embargo until 2 pm Eastern Time on the date of publication. For more information, please contact onepress@plos.org. Kind regards, Rubeena Zakar, Ph.D Section Editor PLOS ONE Additional Editor Comments (optional): Reviewers' comments: Reviewer's Responses to Questions Comments to the Author 1. If the authors have adequately addressed your comments raised in a previous round of review and you feel that this manuscript is now acceptable for publication, you may indicate that here to bypass the “Comments to the Author” section, enter your conflict of interest statement in the “Confidential to Editor” section, and submit your "Accept" recommendation. Reviewer #1: All comments have been addressed Reviewer #5: All comments have been addressed Reviewer #6: (No Response) Reviewer #7: All comments have been addressed ******** 2. Is the manuscript technically sound, and do the data support the conclusions? The manuscript must describe a technically sound piece of scientific research with data that supports the conclusions. Experiments must have been conducted rigorously, with appropriate controls, replication, and sample sizes. The conclusions must be drawn appropriately based on the data presented. Reviewer #1: Yes Reviewer #5: Yes Reviewer #6: Yes Reviewer #7: Yes ****** 3. Has the statistical analysis been performed appropriately and rigorously? Reviewer #1: Yes Reviewer #5: Yes Reviewer #6: Yes Reviewer #7: Yes ****** 4. Have the authors made all data underlying the findings in their manuscript fully available? The PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception (please refer to the Data Availability Statement in the manuscript PDF file). The data should be provided as part of the manuscript or its supporting information, or deposited to a public repository. For example, in addition to summary statistics, the data points behind means, medians and variance measures should be available. If there are restrictions on publicly sharing data—e.g. participant privacy or use of data from a third party—those must be specified. Reviewer #1: Yes Reviewer #5: Yes Reviewer #6: Yes Reviewer #7: Yes ****** 5. Is the manuscript presented in an intelligible fashion and written in standard English? PLOS ONE does not copyedit accepted manuscripts, so the language in submitted articles must be clear, correct, and unambiguous. Any typographical or grammatical errors should be corrected at revision, so please note any specific errors here. Reviewer #1: No Reviewer #5: Yes Reviewer #6: Yes Reviewer #7: Yes ****** 6. Review Comments to the Author Please use the space provided to explain your answers to the questions above. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. (Please upload your review as an attachment if it exceeds 20,000 characters) Reviewer #1: In the introduction section from line 88 to line 90 there are empty lines. Line 147 is should be resultS Table 2. should be named: “pregnancy outcomes of the study population” without “The” Table 3. should be named: Odds ratio and 95% confidence intervals of adverse pregnancy outcomes of immigrant women. Check out please you included an extra “155”. It was a cut & paste mistake for sure. Line 198. Table 3 does not “represents”, I guess you wanted to say “presents” Also in line 198, I would add the word “unadjusted” in this sentence: “The odds of GDM, preeclampsia, CS, placental abruption, placental previa, PPH, PH, and UAE was lower in foreign women than Korean women.” In line 215 and 216 why you did not mention the protection against induction? “Immigrant women were protected against having preeclampsia and PPH and 216 higher risk of GDM, and CS compared to Korean women after adjustment for age, parity, and CCI.” Line 261 it should be outcomeS There are still some spelling mistakes. I suggest you perform a language edition to your manuscript. Reviewer #5: None------------------------------------------------------------------------------------------------------------------------------------------- Reviewer #6: Appreciate the work of author. Author has clearly mentioned the study population, just a simple question to author about the rational behind selection of 9 years study duration? Is it just because the medical record about pregnancy during that time were available or there is any rational for interracial marriage and pregnancies during that period? Thank you Reviewer #7: The title of the study, aim and basic statistical analysis demonstrating pregnancy outcomes between Korean women and immigrant women appear appropriate and linked adequately. ****** 7. PLOS authors have the option to publish the peer review history of their article (what does this mean?). If published, this will include your full peer review and any attached files. If you choose “no”, your identity will remain anonymous but your review may still be made public. Do you want your identity to be public for this peer review? For information about this choice, including consent withdrawal, please see our Privacy Policy. Reviewer #1: No Reviewer #5: No Reviewer #6: No Reviewer #7: Yes: Nnodimele Onuigbo ATULOMAH PhD ******** Attachments Attachment Submitted filename: Third review_immigrant Preg outcomes.docx https://doi.org/10.1371/journal.pone.0278193.r007
Formally Accepted
17 Nov 2022 Acceptance Letter - Rubeena Zakar, Editor PONE-D-21-06981R3 Pregnancy outcomes of immigrant women living in Korea: A population-based study Dear Dr. Jeong: I'm pleased to inform you that your manuscript has been deemed suitable for publication in PLOS ONE. Congratulations! Your manuscript is now with our production department. If your institution or institutions have a press office, please let them know about your upcoming paper now to help maximize its impact. If they'll be preparing press materials, please inform our press team within the next 48 hours. Your manuscript will remain under strict press embargo until 2 pm Eastern Time on the date of publication. For more information please contact onepress@plos.org. If we can help with anything else, please email us at plosone@plos.org. Thank you for submitting your work to PLOS ONE and supporting open access. Kind regards, PLOS ONE Editorial Office Staff on behalf of Dr. Rubeena Zakar Section Editor PLOS ONE https://doi.org/10.1371/journal.pone.0278193.r008

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