How does ART affect risk of stillbirth?
A study by researchers from the Centers for Disease Control and Prevention shows that use of assisted reproductive technology (ART) is associated with a reduced risk of stillbirth prior to 28 weeks’ gestation. The findings, based on data from births in Connecticut, Florida, Massachusetts and Michigan, were presented at the 66th Annual Clinical and Scientific Meeting of the American College of Obstetricians and Gynecologists.
The authors analyzed information from linked ART surveillance and vital records from the four states to examine trends in stillbirth rates and estimated adjusted risk ratios (aRRs) for associations between ART and stillbirth. Adjustments were made for maternal characteristics, pregnancy history, and pre-pregnancy medical conditions. The data also were stratified by plurality and gestational age < 28 and > 28 weeks. ICD-10 codes were used to examine causes of stillbirth.
Outcomes from a total of 15,822 stillbirths between 2006 and 2011 were examined (282 with ART; 15,540 without ART). For both singletons and multifetal pregnancies, rates of stillbirth with ART were lower than when the technology was not used (3.1 versus 6.0 and 9.4 versus 18.3, respectively). At < 28 weeks, the risk of stillbirth among ART pregnancies was significantly lower than for non-ART pregnancies (aRR 0.38, 95% confidence interval [CI] 0.22- 0.65 for singletons and aRR 0.63, 95% CI 0.42-0.94 for multiples).
For ART and non-ART pregnancies, leading causes of stillbirth were similar: maternal conditions such as hypertension, infection, respiratory disease, periodontal disease. incompetent cervix (16.6%); and fetal issues such as placental abnormalities (9.8%); umbilical cord conditions (9.2%); chorioamnionitis (3.8%); and low birth weight (2.7%).
The authors believe that in the ART group, the lower rates of stillbirth seen at < 28 weeks may be because of earlier detection and management of fetal and maternal conditions.