PONE-D-23-37685Cesarean sections among maternal deaths in Mexico: Obstetric Risk Profiles and Other CorrelatesPLOS ONE

Dear Dr. Fritz,

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. The revision outlined in the attachment  (which also addresses the reviewers comments) are required for us to consider the paper for publication. 

 I am confident that the issues raised can be addressed hence the recommendation for 'major revision' instead of outright rejection . Because of the work  required, I would like to suggest that you consider submitting the revised manuscript by Feb 16 2024 11:59PM. 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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We look forward to receiving your revised manuscript.

Kind regards,

 Lawrence Chauke, PHD, MSc (Clinical Research), Cert Maternal and Fetal Medicine (SA), MMed (O&G), FCOG(SA), MBCHB, BTh, Dip HIV Man, 

Academic Editor

PLOS ONE

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Additional Editor Comments:

Dear Fritz, Jimena and colleagues

Thank you very much to you and your team for submitting your research for consideration for publication to PLOSONE. The paper addresses and important topic of global interest. The rising rate of caesarean section and the less than optimal decline in maternal mortality is a major concern globally . Indeed existing data suggests that the world might not achieve the Sustainable Development Goal (SDG) of reducing maternal mortality to less than 70 000 per 100 000 livebirths by the year 2030 if the situation continue as is. Studies like yours is important in that they provide additional insight into some of the factors that should be looked into in the global pursuit to achieve the 2030 SDG 3.1. You provide a compelling background and justification for the study . Thank you for doing that. The paper is a bit difficult to follow as is at present and perhaps you should look at the following points to try and improve the readability of your work and also the chances of the paper being published:

1. Title

On reading the paper one gets the impression that the aim of the paper was to assess the association between mode of delivery, obstetrics risk factors and maternal deaths. If that is the case, you might want to revise the title to reflect this. Please refer to the PLOSONE author resource (https://plos.org/resource/how-to-write-a-great-title/) for guidance on how to write a winning title.

2.Research aim/objectives

Consider using scientific language to communicate the aim of the study and avoid using flowery words like unravel and elucidating. The reader should be very clear from reading the aim of the study as to what the study is all about. This is a bit not clear at present. May be the aim should be to assesses the association between the mode of delivery , maternal characteristics and maternal deaths or assess the contribution of mode of delivery and maternal characteristic on maternal deaths , for example.

3. Method

3.1. Thanks for describing the sources of your data

3.2. Consider writing this section in a past tense as recommended by the reviewers

3.3. Outcome variables: It is very important to chose the outcome variables carefully to ensure that they answer the research question/ objectives. The socio-demographic and pregnancy variables chosen are appropriate. It would have been more useful to also look at co-morbid conditions as these could potentially influence maternal deaths. In other words, is it simply having a caesarean section or having a caesarean section in the background of other co-morbid conditions (or other factors) that increases the risk of maternal death?. What about the experience of the surgeon and the level of care of the public healthcare facilities since majority of the deaths took place in public sector facilities. The following article might be of assistance ( Gebhardt G S, Fawcus S, Moodley J, Farina Z. Maternal death and caesarean section in South Africa: Results from the 2011 - 2013 Saving Mothers Report of the National Committee for Confidential Enquiries into Maternal Deaths. SAMJ, S. Afr. med. j. [Internet]. 2015 Apr [cited 2023 Dec 29] ; 105( 4 ): 287-291. Available from: http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S0256-95742015000300025&lng=en. http://dx.doi.org/10.7196/SAMJ.9351.)

4. Results

4.1. From the data, it seems like the were more deaths in the normal vaginal delivery group compared to caesarean section but you seem to lean more on caesarean section related maternal deaths which are less compared to the normal delivery group. There is also notable significant difference between the women who died after caesarean section and those following normal delivery but this data does not seem to be addressed by the paper. It might be worth spending some time looking and scrutinising this data as this might be something you should look include in your multimodal regression analysis.

4.2. Thank you for using the Robson classification to show the most indication for caesarean section and the risk of dying according to the Robson group.

4.3. Consider separating diagnosis and cause of death. Haemorrhage is the triggering event but what did the women die of ? Is it hypovolaemic shock? Those with pre-eclampsia did they die from bleeding , brain haemorrhage , embolism, etc? You tried to do this in Table 4 but can be further improved. Perhaps you need to scrutinise the data even further.

5. Conclusion: It would be appropriate to comment on this after the revised version because of the lack of alignment between the aim of the study, challenges with the interpretation and the conclusion arrived at.

6. Additional comments: Please see incorporate the specific comments from the reviewers in addition to the above.

I hope that the review does not discourage you. Looking forward to the revised version.

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: No

Reviewer #2: Yes

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2. Has the statistical analysis been performed appropriately and rigorously?

Reviewer #1: Yes

Reviewer #2: Yes

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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: Yes

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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: No

Reviewer #2: Yes

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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: General

Thank you for submitting the manuscript and the intention to share clinical experience and possible solutions for the Mexican populations with the rest of readership of PLOS ONE journals.

The title of the study “Cesarean sections among maternal deaths in Mexico: Obstetric Risk Profiles and

Other Correlates” suggest that maternal death will be a major point of discussion. However, this was not the case. Perhaps consider revising the title.

The manuscript requires Proofreading for scientific language and grammatical errors.

Introduction

Third paragraph about the trend of slowing in the decrease of maternal deaths…

Please such statistics should be made available here for the reader to understand that there has been a slowdown.

Fourth paragraph about potential strategies…

This should be noted that it cannot lead to understanding the cause as association does not equal casualty.

The last paragraph rationalizing the study….

How was the deduction of the caesarean sections being unnecessary and potentially contributing to maternal deaths made?

Study design, population, and data sources

This section should be written in past tense.

There are grammatical errors that need to be corrected. I recommend proofreading by an experienced proofreader or author.

Sentence that begins with “Briefly the BIRMM…”, need to be reconstructed. The word "briefly" appears to be related to what the BIRMM does. Perhaps remove it as it makes the sentence lose its meaning.

Use of Data and ethics: Even though such is readily accessible, permission to be used for research still need to be obtained. Therefore, this section should also indicate such. The use of retrospective data does not imply that ethics clearance is not required, kindly include this information on this section.

On variables: write in past tense.

A sentence on “years of schooling…”, this needs to be clarified. Was this about grades? It cannot be the number of years at school as that may also include those who had failed as progressing as the number of years, they are at school increases.

Section with “place where death occurred…”, events such as dying at home doesn’t always imply that there was no access to healthcare. Patients could have had a Pulmonary Embolus and die before transportation to hospital.

Statistical Analysis

Second paragraph on logistic regression: What was the rationale for estimating the probability of a Caesarean Section being done?

Results

There are several grammatical errors that need to be corrected.

Sentence “it was found that among the total number of births by c-section, 31.4% of women had a previous caesarean section, whereas in vaginal deliveries, only 17.4% had this characteristic (p<0.001)”. Does this imply "only 17.4% who delivered vaginally had previous caesarean section"?

Table 2: Compared to the data on text, it appears that there were more maternal deaths in caesarean sections than NVDs. Please confirm and correct.

Civil status of “united”, the phrase "united" may be easily understood in your country. However, the manuscript is written for distribution worldwide. Consider using a term that is easily understandable and that won’t be ambiguous in other regions.

Table 2: What does Antenatal Control mean?

Table 2: Death site: with regards to private institutions, the current results and percentages on this table gives the impression that deaths in private sector were far less. However, this was not the case as they are being shown as percentage of whole. When you calculate private hospitals alone, the picture is difference. For example, 140 of 341 is 41%, etc. Please rephrase.

The sentence that reads: “… terms of the place of death, it was found that 82.4% of the deaths of women who underwent a cesarean section occurred in a public institution, while in vaginal births, it was observed in 69.1% of cases.” Kindly rephrase this sentence to restore meaning.

Page 15: Sentence “Based on the data, it can be inferred that private institutions (p<0.001, CI 95%: 0.54-0.65) exhibited the highest tendency to perform this surgical procedure in women who eventually died.” Please review the percentage calculated as individual institution to make a better comparison.

Discussion

Reference this section: “The stratification into Robson's groups can be beneficial in identifying the obstetric and gynecological characteristics that have the greatest impact on the practice of cesarean sections. This classification system helps in distinguishing cases where the procedure was appropriate indicated from cases where it may have been unnecessary.”

Paragraph 4: IIn group 4 (multiparous women without a previous uterine scar, carrying a single pregnancy in cephalic position, at or beyond 37 WOG), a high proportion of cesarean sections (67.21%) was observed…” Is there no association with hypertensive diseases in this group as there was increased C/.S rate in hypertensives?. (they could be nulliparous, singleton, no previous C/S but abruption or f/d from insufficiency)

The sentence “Therefore, the high rate this group also suggests a potential overuse of this surgical intervention, disregarding the favorable likelihood of spontaneous labor for multiparous women.” Without knowing the indications for caesarean sections in all these categories, it is unfair to use the phrase "overuse of this procedure”.

The sentence “However, recent studies indicate that a previous cesarean is not an absolute indication for performing a cesarean section”, similarly, finding or describing the indications would be most relevant. I suggest you describe the indications first before making this strong statement.

The sentence “These findings further support the notion of an overuse of cesarean sections in Mexico, as these groups do not have inherent characteristics that necessitate a cesarean deliver”, what was reported as indications? This statement is unjust and unfair unless indications are known.

The sentence “It is interesting to note the disparity between the findings of the present study and the study conducted by Tura et al, where they reported that the largest proportion of cesarean sections was performed in groups 3, 5 and 1, with 21.4%, 21.1%, and 19.3% respectively” The main disparity is that your study was for patients who died. Therefore, it should not surprise you. These groups are not the same and cannot be compared directly.

The sentence “This discrepancy may indicate that, despite receiving adequate prenatal care, some cesarean sections are performed without sufficient medical justification during labor and delivery.” What were the recorded indications for caesarean section?

The sentence “This observation raises concerns that a cesarean section without clear clinical justification may increase the probability of maternal death.” This statement appears to be incorrect under the context.

The sentence “For instance, a study by Lisonkova et al. found that the risk of severe maternal morbidity was higher in planned cesarean deliveries compared…”, This reference looked at morbidity and not primarily mortality and therefore may not be compared directly. It was also predominantly on obese patients.

The sentence “The absence of a control group of surviving women significantly hampers the ability to ascertain causal relationships between cesarean section rates and maternal mortality…”, Was it not possible to have this control group? These patients’ records are likely to be available as well.

Conclusion

The conclusion about "overuse of caesarean sections" is not appropriate because the recorded indications at booking were disregarded during analysis of this data.

The stark contrast in C/S in private versus public sector warrant a comment about further exploration into the drivers of caesarean section in the private sector in your country or comment with available local data. This is probably not much different from other countries.

Reviewer #2: Results section, page 8 first paragraph needs to be reviewed - grammar errors

Table 2 - antenatal/prenatal control sounds weird, change wording

Cesarean section and c-section interchanged a lot throughout the article, sometimes in the same paragraph - please review

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Reviewer #1: No

Reviewer #2: No

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Attachments

Attachment

Submitted filename: CS and Maternal deaths PLOSONE.docx

Obstetric Risk Profiles and Causes of Death: Estimating their Association with Cesarean Sections Among Maternal Deaths in Mexico

PONE-D-23-37685R1

Dear Dr. Dear Fritz, Jimena and colleagues,

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.

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Kind regards,

Hlengani Lawrence Chauke, MBCHB, BTh, Dip HIV Man, FCOG, MMED (O &G), MSc

Academic Editor

PLOS ONE

Additional Editor Comments:

Thank you for submitting the revised manuscript on maternal deaths associated with caesarian sections in Mexico. The purpose of this study was to analyze maternal deaths, focusing on obstetric risk factors, causes of death, and their association with caesarian sections. The findings provide valuable insights into the maternal deaths related to caesarian sections and emphasize the need for increased attention to the indications and circumstances surrounding these procedures. The article is well-written, with a solid introduction, method, and results sections. The statistical methods used are appropriate, and the discussion section exhibits a thorough understanding of the subject matter and relevant literature. The references are appropriately cited. In conclusion, the revised manuscript has addressed all the recommendations from the reviewers. Thank you for taking the time to incorporate the reviewers' recommendations.

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 #2: All comments have been addressed

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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 #2: Yes

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3. Has the statistical analysis been performed appropriately and rigorously?

Reviewer #1: Yes

Reviewer #2: Yes

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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

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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

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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: Thank you for addressing all comments. The manuscript is well written, results are well presented, and the modified discussion chapter shows marked improvements.

Kindly subject this paper to Proof Reading either by a Professional Proofreader or utilize the services from PLOS ONE.

Reviewer #2: (No Response)

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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: Yes: Dr. Langanani Mbodi

Reviewer #2: No

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