Objective: To study fetal weight gain and its association with adverse perinatal events in a serially scanned high-risk population.
Subjects and methods: A total of 200 pregnant women considered at increased risk of uteroplacental insufficiency had a total of 1140 scans in the third trimester, with a median of six scans in each pregnancy. The average fetal growth rate was retrospectively calculated for the last 6 weeks to birth, and expressed as daily weight gain in grams per day. Adverse pregnancy outcome was defined as operative delivery for fetal distress, acidotic umbilical artery pH (< 7.15), or admission to the neonatal intensive care unit (NICU).
Results: Fetuses with normal outcome in this high-risk pregnancy population had an average antenatal growth rate of 24.2 g/day. Compared to pregnancies with normal outcome, the growth rate was slower in those that required operative delivery for fetal distress (20.9 g/day, p < 0.05) and those that required admission to the NICU (20.3 g/day, p < 0.05). The growth rate in pregnancies resulting in acidotic umbilical artery pH also seemed lower, but this did not reach statistical significance.
Conclusions: Impaired fetal weight gain prior to birth is associated with adverse perinatal events suggestive of growth failure.