Accuracy of clinical suspicion of growth restriction at term despite a normal growth ultrasound: A retrospective cohort study.

Background: Small for gestational age (SGA) is a major determinant of poor perinatal outcome. Detecting SGA at term using ultrasound is challenging and we often plan birth based on clinical assessment. Aims: To determine the incidence of SGA infants with birthweight <10th centile among women undergoing planned birth at term for suspected SGA despite a normal estimated fetal weight (EFW) on ultrasound at 35–37 weeks. Materials and Methods: We performed a retrospective study including all women with a fetal growth ultrasound at ≥35 weeks reporting an EFW ≥ 10th centile (appropriate for gestational age, AGA) who subsequently had an induction of labour or caesarean birth at ≥37 weeks due to ongoing clinical suspicion of SGA between 2012–2014. The primary outcome was the incidence of SGA newborns using customised centiles. Results: There were 532 women who had a planned birth for clinical suspicion of SGA during the study period. Of these, 205 (38.5%) had an AGA fetus on ultrasound ≥35 weeks but were subsequently delivered because of a persisting clinical suspicion of SGA on abdominal assessment. Sixty‐eight percent (n = 139/205) delivered an SGA infant. Furthermore, almost half of these SGA infants (47.5%) had a birthweight <3rd centile. Neonatal outcomes were worse for the SGA infants, with 15.1% (n = 21/205) requiring special care nursery compared to 1.5% (n = 1/205) of those AGA at birth. Conclusions: A reassuring ultrasound with EFW ≥10th centile in the late third trimester should not override clinical concerns of impaired fetal growth at term. [ABSTRACT FROM AUTHOR]