Associations between maternal obesity and severe maternal morbidity: Findings from the French EPIMOMS population‐based study

Abstract

Background Maternal obesity is increasing. There is growing evidence of its effect on severe maternal morbidity. We assessed prepregnancy obesity as an independent risk factor for severe maternal morbidity by timing and cause. Methods We designed a case‐control analysis within the EPIMOMS prospective population‐based study conducted in six French regions in 2012‐2013 (182 309 women who delivered at ≥22 weeks). Cases were all women who experienced severe maternal morbidity during pregnancy to 42 days postpartum as per a multicriteria definition derived by national expert consensus (n = 2540, severe maternal morbidity prevalence 1.4%). Controls were randomly selected from the same health centres (n = 3651). The association between obesity and severe maternal morbidity was assessed from fitting multivariable logistic regression models: overall, by timing (antepartum and intrapartum/ postpartum), and by cause. Results Prepregnancy obesity was associated with overall severe maternal morbidity (adjusted odds ratio [OR] 1.34, 95% confidence interval [CI] 1.14, 1.59) and antepartum severe maternal morbidity (OR 2.07, 95% CI 1.61, 2.65), but not with intra/postpartum severe maternal morbidity (OR 1.15, 95% CI 0.96, 1.38). Among antepartum severe maternal morbidity, severe hypertensive disorders were most strongly associated with obesity (OR 2.50, 95% CI 1.85, 3.40) but the risk of antepartum severe maternal morbidity due to other causes was also increased among obese women (OR 1.64, 95% CI 1.13, 2.37). Obesity was not associated with severe postpartum haemorrhage (OR 1.12, 95% CI 0.92, 1.37). Conclusion Obesity is associated with an increased risk of antepartum, but not intra/ postpartum, severe maternal morbidity.

Maternal obesity and severe maternal morbidity—It is time to ask new research questions

“…About 14% of the women with SMM and 11% of controls in the Siddiqui study were obese, and about 20% in both groups were overweight. 1 The authors found significant statistical associations between maternal obesity and both overall SMM (adjusted odds ratio [OR] 1.34, 95% confidence interval [CI] 1.14, 1.58) and antepartum SMM (adjusted OR 2.07, 95% CI 1.62, 2.66), but not intrapartum/ postpartum SMM. Associations between maternal obesity and antepartum SMM were statistically significant, and of higher magnitude for SMM from severe hypertensive disorders than SMM from all other conditions.…”

“…Given its increasing prevalence, serious associated conditions, and management complications in pregnancy and the postpartum period, obesity represents an important health care problem in women of reproductive age throughout the world . Significant knowledge gaps exist in the pathophysiology of obesity, its clinical manifestations in pregnancy, and its implications for management during pregnancy and delivery .…”

“…In this issue of Paediatric and Perinatal Epidemiology , Siddiqui et al report findings from a study examining associations between World Health Organization‐defined body mass index (BMI) categories of underweight, normal weight, overweight, and obesity and severe maternal morbidity (SMM) in France in 2012‐2013—a time when maternal obesity was just reaching the low double digits. The study has considerable strengths.…”

“…Cases were all women from a source population of over 180 000 pregnant women (ie, about one‐fifth of deliveries in France and thought to be nationally representative) who developed SMM . The SMM definition was developed through a Delphi process for the EPIMOMS study and combined 16 diagnostic, interventional, and organ dysfunction criteria; intensive care unit admission; and death . The use of a composite SMM outcome measure, albeit not validated and potentially introducing bias towards the null, allows for comparison with similar population‐based studies in like settings.…”

“…Given its increasing prevalence, serious associated conditions, and management complications in pregnancy and the postpartum period, obesity represents an important health care problem in women of reproductive age throughout the world. 1,2 Significant knowledge gaps exist in the pathophysiology of obesity, its clinical manifestations in pregnancy, and its implications for management during pregnancy and delivery. 2 As no study is perfect, women in the control group were not matched to cases on key sociodemographic or medical characteristics, but selected from among those cared for after 22 weeks' gestation at the same health facilities as the cases.…”