Abstract
Objective We sought to investigate the positive predictive value of ultrasound-diagnosed fetal
growth restriction (FGR) for estimating small for gestational age (SGA) at birth.
Secondary objectives were to describe clinical interventions performed as a result
of FGR diagnosis.
Study Design This was a retrospective cohort of pregnancies diagnosed with FGR over 3 years at
a single institution. Maternal demographics, antenatal and delivery data, and neonatal
data were collected. Descriptive statistics and linear regression were conducted.
Results We included 406 pregnancies with diagnosis of FGR in second or third trimester. Median
birth weight percentile was 17 (interquartile range: 5–50) and only 35.0% of these
fetuses were SGA at birth. The positive predictive value of a final growth ultrasound
below the 10th percentile for SGA at birth was 56.9%. Patients averaged eight additional
growth ultrasounds following FGR diagnosis. One hundred and fourteen (28.1%) received
antenatal steroids prior to delivery, and 100% of those delivered after more than
7 days following administration. There were 6 fetal deaths and 14 neonatal deaths.
Conclusion In the majority of cases, pregnancies diagnosed with FGR during screening ultrasounds
resulted in normally grown neonates and term deliveries. These patients may be receiving
unnecessary ultrasounds and premature courses of corticosteroids.
Keywords
fetal growth restriction - ultrasound - pregnancy - antenatal corticosteroids