Twin pregnancy and perinatal outcomes: Data from ‘Birth in Brazil Study’

Ana Paula Esteves-Pereira; Antônio José Ledo Alves da Cunha; Marcos Nakamura-Pereira; Maria Elisabeth Moreira; Rosa Maria soares madeira Domingues; Elaine Fernandes Viellas; Maria do Carmo Leal; Silvana Granado nogueira da Gama

doi:10.1371/journal.pone.0245152

Peer Review History

Original SubmissionAugust 7, 2020
13 Oct 2020 Decision Letter - Andrew Sharp, Editor PONE-D-20-23490 Twin pregnancy and perinatal outcomes: data from ‘Birth in Brazil Study’ PLOS ONE Dear Dr. Esteves-Pereira, 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 12/11/2020. 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. 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Please see http://www.bmj.com/content/340/bmj.c181.long for guidelines on how to de-identify and prepare clinical data for publication. For a list of acceptable repositories, please see http://journals.plos.org/plosone/s/data-availability#loc-recommended-repositories. We will update your Data Availability statement on your behalf to reflect the information you provide. 3. Please amend your manuscript to include your abstract after the title page. Additional Editor Comments: A large cohort study of twins and singletons in brazil. The authors have attempted to compare the outcomes of twins to singletons at a variety of gestational age brackets. Likely, the increased age and hypertensive disorders are linked to assisted reproduction but the authors did not assess this. This would fit with others studies in twins. Likewise chorionicity was not assessed which is a common failing of large cohorts of twins The lack of detail about the incidence of preterm birth <34 weeks for twins is a shame as this is one of the highest risk groups. In addition, it is unclear which proportion of these babies in each group were delivered due to other clinical concerns or who laboured spontaneously. The approach to interpreting the data would be significantly different if the cause were not potentially preventable, i.e. delivering due to TTTS or severe IUGR in which case you would accept the risks of prematurity whatever they are On page 5 please make the definition of IUGR and SGA clearer as <3rd and <10th respectively. You do this in the tables so I suspect you are using the Delphi criteria but the text does not make this clear Page 5 skin colour is an unusual term to use for ethnicity for this reviewer. I would suggest changing this to ethnicity to improve the translation to other readers. Table 1 can you split the mode of delivery into elective (no labour) CS and emergency CS. It is unclear at present Please add data for stillbirths and neonatal deaths to all relevant tables [Note: HTML markup is below. Please do not edit.] Reviewers' comments: [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.0245152.r001
Revision 1
1 Dec 2020 Author Response Manuscript “Twin pregnancy and perinatal outcomes: data from ‘Birth in Brazil Study” [PONE-D-20-23490]. Each point raised has been answered as follows: 1. Please ensure that your manuscript meets PLOS ONE's style requirements, including those for file naming. Response: The manuscript was amended to meet PLOS ONE's style requirements, including those for file naming. 2. We note that you have indicated that data from this study are available upon request. PLOS only allows data to be available upon request if there are legal or ethical restrictions on sharing data publicly. Response: The authors have upload the minimal anonymized data set necessary to replicate the study findings as a Supporting Information file “NB1_GEMEOS_PLOSONE.sav” 3. Please amend your manuscript to include your abstract after the title page. Response: The abstract (now page 2) was included in the manuscript after the title page. A large cohort study of twins and singletons in brazil. The authors have attempted to compare the outcomes of twins to singletons at a variety of gestational age brackets. 4.1. Likely, the increased age and hypertensive disorders are linked to assisted reproduction but the authors did not assess this. This would fit with others studies in twins. Likewise chorionicity was not assessed which is a common failing of large cohorts of twins. Response: Since the main objective of “Birth in Brazil” study was not to study twin births, it was not possible to determine whether the twin pregnancy was monochorionic or dichorionic. Neither was it possible to discern which woman used assisted reproductive technologies (ART). This is a limitation of the study, addressed in the discussion section. However, we described that the proportion of twins was higher in the private sector and in women >39 years, which may be due, at least in some extent, to using ART more frequently than younger women from the public sector do. We will be able to fully address this hypothesis in Birth in Brazil 2, with data collection beginning in 2021. 4.2.The lack of detail about the incidence of preterm birth <34 weeks for twins is a shame as this is one of the highest risk groups. In addition, it is unclear which proportion of these babies in each group were delivered due to other clinical concerns or who laboured spontaneously. The approach to interpreting the data would be significantly different if the cause were not potentially preventable, i.e. delivering due to TTTS or severe IUGR in which case you would accept the risks of prematurity whatever they are. Response: The authors have included two supporting files (Supplemental_Table_1 and Suplemental_Figure_1), which are described in the results section (page 9). These files show the detail about the incidence of preterm birth <34 weeks for twins and singletons, as well as the proportion of newborns with provider-initiated onset of labour (induction or elective caesarean) or who laboured spontaneously. 4.3. On page 5 please make the definition of IUGR and SGA clearer as <3rd and <10th respectively. You do this in the tables so I suspect you are using the Delphi criteria but the text does not make this clear. Response: In now page 6, we changed the original text to: “Appropriate birth weight for gestational age was assessed by Intergrowth-21st intrauterine growth curves, considering birth weight <10th percentile as small for gestational age (SGA) and birth weight <3th percentile as intrauterine growth restriction (IUGR).” 4.4. Page 5 skin colour is an unusual term to use for ethnicity for this reviewer. I would suggest changing this to ethnicity to improve the translation to other readers. Response: The term “skin colour” was changed for “ethnicity” in the text and tables. 4.5. Table 1 can you split the mode of delivery into elective (no labour) CS and emergency CS. It is unclear at present. Response: Table 1 (page 10) and its results (page 9) were updated as suggested. 4.6. Please add data for stillbirths and neonatal deaths to all relevant tables Response: The data for stillbirths and neonatal deaths were included in tables 2 and 4. Attachments Attachment Submitted filename: Response_Review.docx https://doi.org/10.1371/journal.pone.0245152.r002
23 Dec 2020 Decision Letter - Andrew Sharp, Editor Twin pregnancy and perinatal outcomes: data from ‘Birth in Brazil Study’ PONE-D-20-23490R1 Dear Dr. Esteves-Pereira, 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, Andrew Sharp, PhD Academic Editor PLOS ONE Additional Editor Comments (optional): Reviewers' comments: https://doi.org/10.1371/journal.pone.0245152.r003
Formally Accepted
30 Dec 2020 Acceptance Letter - Andrew Sharp, Editor PONE-D-20-23490R1 Twin pregnancy and perinatal outcomes: data from ‘Birth in Brazil Study’ Dear Dr. Esteves-Pereira: 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. Andrew Sharp Academic Editor PLOS ONE https://doi.org/10.1371/journal.pone.0245152.r004

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