Cesarean section and the gestational duration of subsequent pregnancies: A nationwide register-based cohort study.

<h4>Introduction</h4>Preterm delivery risk is increased for women with a previous cesarean section, which are becoming more common worldwide. However, this risk is based on studies which have not fully accounted for selection bias, and the studied outcomes have been limited to the study...

Full description

Saved in:
Bibliographic Details
Main Authors: Felix Evers, Christopher Flatley, Karin Ytterberg, Julius Juodakis, Pol Solé-Navais, Bo Jacobsson
Format: Article
Language:English
Published: Public Library of Science (PLoS) 2025-01-01
Series:PLoS ONE
Online Access:https://doi.org/10.1371/journal.pone.0317492
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1823861057809022976
author Felix Evers
Christopher Flatley
Karin Ytterberg
Julius Juodakis
Pol Solé-Navais
Bo Jacobsson
author_facet Felix Evers
Christopher Flatley
Karin Ytterberg
Julius Juodakis
Pol Solé-Navais
Bo Jacobsson
author_sort Felix Evers
collection DOAJ
description <h4>Introduction</h4>Preterm delivery risk is increased for women with a previous cesarean section, which are becoming more common worldwide. However, this risk is based on studies which have not fully accounted for selection bias, and the studied outcomes have been limited to the study of early deliveries. This study aimed to determine the impact of previous delivery modes on the incidence of deviant duration of subsequent pregnancies.<h4>Material and methods</h4>This retrospective cohort study used clinical data registered in the Swedish Medical Birth Register. 612 935 women with their first two pregnancies and 157 581 women with their first three pregnancies were included. The outcome was the gestational duration of the last pregnancy of the series, depending on previous delivery modes. The associations were analysed with multivariable logistic regression (with the gestational duration categorised) and survival models including Cox regression analyses.<h4>Results</h4>When using standard logistic regression, previous cesarean section was associated with an increased risk of both spontaneous preterm birth (adjusted odds ratio [aOR] 1.67, 95% CI 1.57-1.77) and postterm birth (aOR 1.55, 95% CI 1.49-1.62). However, the more appropriate survival models only showed an association between cesarean section and longer gestational duration of the subsequent pregnancy (adjusted hazard ratio 0.72, 95% CI 0.71-0.73).<h4>Conclusions</h4>The survival model handles bias related to management differences between the exposure and reference groups better than standard logistic regression, making it the statistical method of choice when conducting studies on this research topic. This study shows that the main association between cesarean section and the gestational duration of the subsequent pregnancy is the prolonging of it, which stands in contrast with previous research on the topic.
format Article
id doaj-art-bc85c354b09d40a98ae3b21e7a610004
institution Kabale University
issn 1932-6203
language English
publishDate 2025-01-01
publisher Public Library of Science (PLoS)
record_format Article
series PLoS ONE
spelling doaj-art-bc85c354b09d40a98ae3b21e7a6100042025-02-10T05:30:37ZengPublic Library of Science (PLoS)PLoS ONE1932-62032025-01-01202e031749210.1371/journal.pone.0317492Cesarean section and the gestational duration of subsequent pregnancies: A nationwide register-based cohort study.Felix EversChristopher FlatleyKarin YtterbergJulius JuodakisPol Solé-NavaisBo Jacobsson<h4>Introduction</h4>Preterm delivery risk is increased for women with a previous cesarean section, which are becoming more common worldwide. However, this risk is based on studies which have not fully accounted for selection bias, and the studied outcomes have been limited to the study of early deliveries. This study aimed to determine the impact of previous delivery modes on the incidence of deviant duration of subsequent pregnancies.<h4>Material and methods</h4>This retrospective cohort study used clinical data registered in the Swedish Medical Birth Register. 612 935 women with their first two pregnancies and 157 581 women with their first three pregnancies were included. The outcome was the gestational duration of the last pregnancy of the series, depending on previous delivery modes. The associations were analysed with multivariable logistic regression (with the gestational duration categorised) and survival models including Cox regression analyses.<h4>Results</h4>When using standard logistic regression, previous cesarean section was associated with an increased risk of both spontaneous preterm birth (adjusted odds ratio [aOR] 1.67, 95% CI 1.57-1.77) and postterm birth (aOR 1.55, 95% CI 1.49-1.62). However, the more appropriate survival models only showed an association between cesarean section and longer gestational duration of the subsequent pregnancy (adjusted hazard ratio 0.72, 95% CI 0.71-0.73).<h4>Conclusions</h4>The survival model handles bias related to management differences between the exposure and reference groups better than standard logistic regression, making it the statistical method of choice when conducting studies on this research topic. This study shows that the main association between cesarean section and the gestational duration of the subsequent pregnancy is the prolonging of it, which stands in contrast with previous research on the topic.https://doi.org/10.1371/journal.pone.0317492
spellingShingle Felix Evers
Christopher Flatley
Karin Ytterberg
Julius Juodakis
Pol Solé-Navais
Bo Jacobsson
Cesarean section and the gestational duration of subsequent pregnancies: A nationwide register-based cohort study.
PLoS ONE
title Cesarean section and the gestational duration of subsequent pregnancies: A nationwide register-based cohort study.
title_full Cesarean section and the gestational duration of subsequent pregnancies: A nationwide register-based cohort study.
title_fullStr Cesarean section and the gestational duration of subsequent pregnancies: A nationwide register-based cohort study.
title_full_unstemmed Cesarean section and the gestational duration of subsequent pregnancies: A nationwide register-based cohort study.
title_short Cesarean section and the gestational duration of subsequent pregnancies: A nationwide register-based cohort study.
title_sort cesarean section and the gestational duration of subsequent pregnancies a nationwide register based cohort study
url https://doi.org/10.1371/journal.pone.0317492
work_keys_str_mv AT felixevers cesareansectionandthegestationaldurationofsubsequentpregnanciesanationwideregisterbasedcohortstudy
AT christopherflatley cesareansectionandthegestationaldurationofsubsequentpregnanciesanationwideregisterbasedcohortstudy
AT karinytterberg cesareansectionandthegestationaldurationofsubsequentpregnanciesanationwideregisterbasedcohortstudy
AT juliusjuodakis cesareansectionandthegestationaldurationofsubsequentpregnanciesanationwideregisterbasedcohortstudy
AT polsolenavais cesareansectionandthegestationaldurationofsubsequentpregnanciesanationwideregisterbasedcohortstudy
AT bojacobsson cesareansectionandthegestationaldurationofsubsequentpregnanciesanationwideregisterbasedcohortstudy