Is obstetric and neonatal outcome worse in fetuses who fail to reach their own growth potential?

Abstract

Objectives To determine the perinatal outcome of fetuses who had birthweights less than that expected from early third trimester ultrasound scanning. Design Retrospective estimation of centile fetal weight at early third trimester ultrasound scanning compared with actual centile birthweight corrected for gestational age, parity and sex. Setting Teaching Hospital Obstetric Unit, London. Subjects 197 unselected women with singleton cephalic pregnancies who were delivered at term in our unit between October 1989 and May 1990. Main outcome measures CTG abnormality, need for fetal blood sampling in labour, meconium-staining of the amniotic fluid, mode of delivery, Apgar scores at 1 and 5 min, need for transfer of baby to neonatal unit, and need for neonatal intubation of the neonate at delivery. Results An actual birthweight >5% less than the birthweight estimated from ultrasound scanning identified 44 babies (22%) with an increased risk of CTG abnormalities (χ²= 8.38, P x= 5.81, P in-utero fetal growth pattern is as important for perinatal outcome as being small for gestational age per se.