Pre-pregnancy Body Mass Index (BMI) and delivery outcomes in a Canadian population

Abstract

BackgroundWorldwide there has been a dramatic increase in the prevalence of overweight and obesity in women of childbearing age. Growing evidence suggests that maternal overweight and obesity is associated with poor maternal and perinatal outcomes. This study evaluated the impact of maternal pre-pregnancy overweight and obesity on pregnancy, labour and delivery outcomes in a cohort of women with term, singleton pregnancies cared for by family physicians in community based practices.MethodsThis study is a secondary analysis of the All Our Babies Cohort, a prospective, community-based pregnancy cohort in Calgary, Alberta. Maternal self-reported data on height and pre-pregnancy weight from term, singleton, cephalic pregnancies (n = 1996) were linked to clinical data on pregnancy and birth events retrieved from electronic health records. Descriptive and bivariate regression analysis were used to compare pregnancy and birth outcomes between women categorized as normal weight, overweight and obese based on the pre-pregnancy BMI. Multinomial regression analysis stratified by type of labour onset examined the association between pre-pregnancy BMI and mode of delivery controlling for maternal age, pre-existent health conditions, parity, fertility treatments, history of C-section and pregnancy complications.ResultsThe cohort consisted of 65.8% normal weight, 23.6% overweight and 10.6% obese women. Women with increased pre-pregnancy BMI were more likely to develop pregnancy complications such as preeclampsia (OR 3.5, CI 2.0-4.6 for overweight; OR 5.3, CI 3.3-8.5 for obese) and gestational diabetes (OR 3.0, CI 1.8-5.0 for overweight; OR 6.5, CI 3.7-11.2 for obese) than normal weight women. Spontaneous onset of labour was recorded in 71.2% of women with normal pre-pregnancy BMI, whereas 39.3% of overweight and 49% of obese women had their labour induced. For women with spontaneous labour, pre-pregnancy BMI was not a significant risk factor for mode of delivery, controlling for covariates. Among women with induced labor, obesity was a significant risk factor for delivery by C-section (adjusted OR 2.2; CI 1.2-4.1).ConclusionsEven among women with term, singleton pregnancies obtaining prenatal care in community-based settings, obese women who undergo labour induction are at increased risk of obstetrical interventions at delivery. These findings highlight the importance of tailored maternal care in pregnancy and at delivery of pregnant women with increased BMI in order to improve the outcomes and wellbeing of these women and their children.Electronic supplementary materialThe online version of this article (doi:10.1186/s12884-014-0422-y) contains supplementary material, which is available to authorized users.

Pregestational body mass index, weight gain during pregnancy and perinatal outcome: a retrospective descriptive study

“…12 As to hypertensive disorders of pregnancy, studies have shown that these conditions are more likely to occur in women who developed a greater GWG; however, most of these studies have significant methodological limitations, since women who developed such hypertensive comorbidities are more likely to present with edema during pregnancy than the normotensive women, and this can result in a higher GWG. 2 …”

“…12 Sobre as desordens hipertensivas na gestação, os estudos têm demonstrado que estas estão mais propensas a acontecer nas mulheres que desenvolveram maior GPG; entretanto, a maioria desses estudos tem importantes limitações metodológicas, pois as mulheres que desenvolvem tais comorbidades hipertensivas são mais propensas a apresentarem edema durante a gestação do que as normotensas, e isso, por sua vez, pode resultar em maior GPG. 2 …”

Associations of maternal pre-pregnancy body mass index and gestational weight gain with birth outcomes in Shanghai, China

“…Accumulating evidence suggests that higher BMI prior to pregnancy is associated with an increased risk of preeclampsia, gestational diabetes, caesarean section, postpartum hemorrhage, and fetal macrosomia1234, whereas maternal underweight is associated with an increased risk of preterm delivery and small-for-gestational-age (SGA)56. Maternal GWG has also been widely studied as an independent indicator of adverse pregnancy outcomes.…”

Gestación en la mujer obesa: consideraciones especiales

“…Las mujeres obesas requieren una atención prenatal y manejo del parto y el puerperio que difi eren de la gestante con peso apropiado. Así, entre otros, las mujeres obesas ti enen más riesgo de ser someti das a inducción del parto y de intervenciones obstétricas en el parto, especialmente la realización de cesáreas (45) . También la gestante obesa requiere de comodidades especiales durante el trabajo de parto y parto que no siempre se encuentran en los centros de atención de parto públicos y privados.…”