The combined effect of pre-pregnancy body mass index and gestational weight gain on the risk of pre-labour and intrapartum caesarean section-The ICE-MCH study

Aino-Maija Eloranta; Ingibjörg Gunnarsdottir; Birna Thorisdottir; Geir Gunnlaugsson; Bryndis Eva Birgisdottir; Inga Thorsdottir; Kristjana Einarsdóttir

doi:10.1371/journal.pone.0280060

The combined effect of pre-pregnancy body mass index and gestational weight gain on the risk of pre-labour and intrapartum caesarean section-The ICE-MCH study

PLoS One. 2023 Jan 5;18(1):e0280060. doi: 10.1371/journal.pone.0280060. eCollection 2023.

Authors

Aino-Maija Eloranta^{1

2

3}, Ingibjörg Gunnarsdottir^{4

5}, Birna Thorisdottir^{6

7}, Geir Gunnlaugsson⁷, Bryndis Eva Birgisdottir^{4

6}, Inga Thorsdottir^{5

6}, Kristjana Einarsdóttir^{8

9}

Affiliations

¹ Institute of Public Health and Clinical Nutrition, School of Medicine, University of Eastern Finland, Kuopio, Finland.
² Institute of Biomedicine, School of Medicine, University of Eastern Finland, Kuopio, Finland.
³ Department of Medicine, Endocrinology and Clinical Nutrition, Kuopio University Hospital, Kuopio, Finland.
⁴ Faculty of Food Science and Nutrition, School of Health Sciences, University of Iceland, Reykjavík, Iceland.
⁵ Unit for Nutrition Research, Health Science Institute, University of Iceland and Landspitali University Hospital, Reykjavík, Iceland.
⁶ Unit for Nutrition Research, Health Science Institute, University of Iceland, Reykjavik, Iceland.
⁷ Faculty of Sociology, Anthropology and Folkloristics, School of Social Sciences, University of Iceland, Reykjavík, Iceland.
⁸ Faculty of Medicine, School of Health Sciences, University of Iceland, Reykjavík, Iceland.
⁹ Centre of Public Health Sciences, Health Science Institute, University of Iceland, Reykjavík, Iceland.

Abstract

Women who are obese before pregnancy have a higher risk of caesarean section than normal weight women. We investigated the combined effect of pre-pregnancy weight and gestational weight gain on pre-labour and intrapartum caesarean section risk. We collected data on 22,763 singleton, term, live deliveries in 2003-2014 from the Icelandic Maternal and Child Health Study (ICE-MCH), based on Icelandic registries. These were the Icelandic Medical Birth Registry and the Saga Maternal and Child Health Database. Pre-pregnancy body mass index was categorised into underweight, normal weight, overweight and obese. Gestational weight gain was classified according to the Institute of Medicine´s recommendation into below, within and above the recommended range. Logistic regression models, adjusted for maternal and gestational characteristics, were used to calculate adjusted odds ratios (AOR) and 95% confidence intervals (CI) for the risk of caesarean section. Obese women had a higher risk of pre-labour (AOR 1.56, 95% CI 1.34-1.81) and intrapartum caesarean section (AOR 1.92, 95% CI 1.70-2.17) than normal weight women in all categories of gestational weight gain. Gestational weight gain above the recommended range, compared to within the range, increased the risk of intrapartum caesarean section among normal weight (AOR 1.46, 95% CI 1.23-1.73) and overweight women (AOR 1.291, 95% CI 1.04-1.60). Gestational weight gain below the recommended range, compared to within the range, increased the risk of pre-labour caesarean section (AOR 1.64, 95% CI 1.20-2.25), but only among overweight women. Women who are obese before pregnancy have a high risk of caesarean section regardless of gestational weight gain. However, women who are normal weight or overweight before pregnancy and gain weight above the recommended range during pregnancy may also have an increased risk of caesarean section.

Copyright: © 2023 Eloranta et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Body Mass Index
Cesarean Section / adverse effects
Child
Female
Gestational Weight Gain*
Humans
Obesity / complications
Overweight / complications
Pregnancy
Pregnancy Complications* / etiology
Pregnancy Outcome
Risk Factors

Grants and funding

A project grant from the Research Fund of the University of Iceland (https://english.hi.is/research/the_university_of_iceland_research_fund_0, author IT). A personal grant from Finnish Cultural Foundation (https://skr.fi/en, author AE). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.