Increased risk of adverse neonatal and maternal outcomes in women with a severe antepartum morbid event

A context of severe maternal complications before labor and delivery is associated with a 10-fold increase in prematurity and neonatal mortality rates, according to the EPIMOMS study. For women, the rates of general anesthesia and emergency cesarean, which are in themselves risky interventions, are also significantly increased. These results support and quantify the links between maternal health and risks for delivery and the newborn.

Article (open access)

Antepartum severe maternal morbidity: A population-based study of risk factors and delivery outcomes. Mégane Raineau, Catherine Deneux-Tharaux, Aurélien Seco, Marie-Pierre Bonnet, for the EPIMOMS Study Group. Paediatr Perinat Epidemiol. 2021;00:1–10. 

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Background: Severe maternal morbidity (SMM) is a key indicator of maternal health. Generally explored without distinction by the timing of the event, it mainly reflects postpartum SMM. Although antepartum (pre-labor) SMM presents specific challenges in its need to optimize the risk-benefit balance for the mother and fetus, its features remain inadequately explored.

Objectives: To explore the causes and risk factors for antepartum SMM, and to describe adverse delivery and neonatal outcomes in women with antepartum SMM.

Methods: We conducted a population-based nested case-control study from the EPIMOMS study (119 maternity hospitals in 6 French regions, 2012-2013, N=182 309 deliveries in the source cohort). Our analysis included all women with antepartum SMM (cases, n=601) compared to a randomly selected sample of women who gave birth without SMM at the same hospitals and time period (controls, n=3650). Antepartum SMM risk factors were identified with multivariate logistic regression following imputation for missing data.

Results: Antepartum SMM complicated 0.33% (95% confidence interval [CI] 0.30, 0.36) of pregnancies. Antepartum SMM risk factors were maternal age ≥35 years (adjusted odds ratio [OR] 1.55, 95% CI 1.22, 1.97), increased body mass index (OR for 5 kg/m2 increase, 1.24, 95% CI 1.14, 1.36), maternal birth in sub-Saharan Africa (OR 1.80, 95% CI 1.29, 2.53), pre-existing medical condition (OR 2.56, 95% CI 1.99, 3.30), nulliparity (OR 2.26, 95% CI 1.83, 2.80), previous pregnancy-related hypertensive disorders (OR 4.94, 95% CI 3.36, 7.26), multiple pregnancy (OR 5.79, 95% CI 3.75, 7.26), irregular prenatal care (OR 1.86, 95% CI 1.27, 2.72). For women with antepartum SMM, preterm delivery, neonatal mortality and transfer to the neonatal intensive care unit were 10 times more frequent than for controls. Emergency caesarean and general anesthesia were more frequent in women with antepartum SMM.

Conclusions: Antepartum SMM is rare but associated with increased rates of adverse delivery and neonatal outcomes.