Postpartum Severe Acute Maternal Morbidity According to Gestational Age
at Delivery in Twin Pregnancies: A Prospective Cohort Study
Abstract
Objective: To assess the association between gestational age at delivery
and postpartum severe acute maternal morbidity (SAMM) in twin
pregnancies. Design: Population-based, national, prospective, cohort
study Setting: From 02/2014 to 03/2015 in France Population: Women with
twin pregnancies who gave birth after 32 weeks of gestation. We excluded
women with fetal death or medical termination of either twin, with
antepartum SAMM, with antepartum conditions responsible for postpartum
SAMM. Methods: Gestational age at delivery was studied as the number of
completed weeks of gestation. We assessed the association between
gestational age at delivery and postpartum SAMM by using multivariable
multilevel modified Poisson regression modelling. Main Outcome Measures:
Composite criteria of postpartum severe acute maternal morbidity
Results: Among the 7,713 women included, 410 (5.3%) developed
postpartum SAMM, mainly (88.5%) postpartum haemorrhage. Compared with
the reference category of 37 weeks, the risk of postpartum SAMM was
significantly lower for all categories of earlier gestational age at
delivery (from aRR=0.34, 95% CI 0.17-0.68 at 32 weeks to aRR=0.71, 95%
CI 0.54-0.94 at 36 weeks), and did not differ for later categories.
Conclusion: In twin pregnancies, compared with delivery at 37 weeks,
delivery at earlier gestational ages is associated with a lower risk of
postpartum SAMM. Continuing pregnancy beyond 37 weeks is not associated
with an increased risk of postpartum SAMM. Funding: Supported by a grant
from the French Ministry of Health (Programme Hospitalier de Recherche
Clinique, AOM2012) and a grant from Université Toulouse III. Keywords:
severe acute maternal morbidity, twin pregnancy, timing of delivery