A study in the August 2009 issue of Obstetrics and Gynecology shows that late prematurity is an independent risk factor for neonatal morbidity. For those of us who aren’t women’s health experts, that means babies born between 34 and 37 weeks of pregnancy are at greater risk for health problems than babies born on or after week 37.
Midwives already know that late prematurity puts babies at risk for complications, but this retrospective study involving nearly 10,000 low-risk pregnancies singles out late prematurity as an independent risk factor. After adjusting for potential confounders, including maternal age, birth weight, and mode of delivery, researchers found a 30-fold increase in complications like respiratory problems, hypoglycemia, and hypothermia in babies who were born at 34 weeks. Researchers also observed a “gradual and consistent decrease” in risk of neonatal morbidity as gestational age increased with risks leveling off at about 39 weeks.
Study authors note that late prematurity has increased dramatically over the past two decades to about 8% of all deliveries and 75% of preterm deliveries. Interestingly, ACOG recently revised their labor induction guidelines, encouraging avoidance of induction before 39 weeks of pregnancy (the previous recommendation was 37 weeks). Do you think this study had anything to do with this?