Delivery by 38 weeks lowers risk of stillbirth in older pregnant women
Delivery by 38 weeks appears to reduce the risk of stillbirth in pregnant women at least 44 years of age, according to a study.
To determine the gestational age at which the risk of foetal or neonatal death associated with delaying delivery by 1 week exceeded the risk of neonatal death associated with immediate delivery, researchers examined a total of 11,957,690 live births, 8,779 stillbirths and 8,664 neonatal deaths that occurred in the United States between 2010 and 2013. Only singleton, nonanomalous pregnancies without hypertensive disease or diabetes were included.
A generalized linear model was used to compare the rate of death associated with immediate delivery to those of expectant management, with the women grouped into six age categories.
Immediate delivery was associated with lower relative risk of neonatal death by 39 weeks across all age groups, with the exception of ≥44 years age group. The odds ratios (ORs) for death were 1.0 (95 percent CI, 0.32 to 3.10) in the <25 years age group, 0.67 (0.19 to 2.37) in the 25 to 29 years age group, 0.80 (0.21 to 2.98) in the 30 to 34 years age group, 0.67 (0.19 to 2.36) in the 35 to 39 years age group, and 0.45 (0.16 to 1.31) in the 40 to 44 years age group.
Among women aged ≥44 years and older, immediate delivery was associated with a lower relative risk of neonatal death by 38 weeks (OR, 0.35; 0.14 to 0.90).
Advanced maternal age carries a greater risk complications such as foetal congenital anomalies, maternal hypertensive disorders, gestational diabetes and pregestational diabetes. These conditions are associated with heightened stillbirth risk. [BJOG 2012;119:276–282; Am J Obstet Gynecol 2007;196:433–444]
Researchers noted that the current finding that delivery by 38 weeks gestational age may reduce the risk of stillbirth in women ≥44 years of age is important given the limited future fertility of mothers in this age group.
“Induction of labour among women 44 years or older at the time of delivery, might be useful in reducing stillbirth. However, it needs to be weighed against compromising maternal outcomes, neonatal morbidity, patient preference and healthcare costs,” researchers said.
“Quantifying and counselling women of advanced maternal age on their risk of stillbirth is important and requires a nuanced approach... Further research regarding the mechanism behind unexplained foetal death in women of advanced maternal age will help determine the most effective forms of prevention,” they added.