Stillbirth may be associated with both severely restricted and excessive fetal growth according to a new study. Radek Bukowski and colleagues from the NICHD Stillbirth Collaborative Research Network looked at fetal growth abnormalities associated with stillbirth using a new technique developed by the Stillbirth Collaborative Research Network to estimate gestational age. Researchers applied this new technique to a study of all the stillbirths and sample of live births over two and a half years at 59 hospitals in the US.
Extremely large or extremely small fetuses at risk
Researchers used three different scales to measure weight and gestational age: population norms, ultrasound or individualized norms. Overall, researchers found that abnormal fetal growth was identified in 25% of stillbirths by comparing to standardized norms and in more than 50% of stillbirths using ultrasound or individualized norms. Small for Gestational Age (SGA: the bottom 10% of the population weight for gestational age) was linked to a 3- to 4-fold increased risk of stillbirth compared to having an appropriate weight fetus based on all three norms. Large for Gestational Age (LGA: the top 10% of weight for age) was linked to an increased risk of stillbirth based on ultrasound and individualized norms, but not population norms. The findings suggest that strategies designed to prevent stillbirth should focus on identifying both severely SG and severely LGA fetuses and monitoring those pregnancies more closely.
Better strategy to identify these babies and monitor the pregnancies
“When accounting for time of death and using norms developed in normal pregnancies, both SGA and LGA birth weights were associated with stillbirth in our study. The association is mainly related severe SGA and LGA pregnancies, with birth weights either below the 5th or above the 95th percentile. Thus, classifying 10% of pregnancies as abnormally grown has the potential to identify 44%-46% of future stillbirths,” stated the authors in their report published in PLOS Medicine.
Source: ScienceDaily, PLOS Medicine