Fetal death diagnosed after 20 weeks of gestation accounts for more than half of annual infant deaths in the U.S. Since birthweight has been considered a surrogate of fetal growth, and a small for gestational age neonate is associated with fetal death, fetal growth restriction is frequently cited as a precedent of antepartum stillbirth. Yet, the relationship between fetal growth and stillbirth is poorly understood. Studies have reported that impairment of fetal growth is associated with fetal and/or neonatal death; however, growth velocity in fetal death has not been assessed.
PRB researchers conducted a longitudinal study of 4,285 singleton pregnancies in African-American women who underwent at least two obstetrical ultrasound examinations (between 14 and 32 weeks) and delivered a live born neonate or experienced an antepartum fetal death. Pregnancies that resulted in fetal death had significantly lower growth velocity of the fetal head circumference, biparietal diameter, abdominal circumference, femur length, and estimated fetal weight than pregnancies with a live-born neonate. Moreover, fetal growth velocity doubled the detection rate of antepartum fetal death compared to the last available scan before diagnosis. Therefore, this study strengthens the importance of considering reduction in fetal growth velocity as a herald of antepartum fetal death. Yet, given the moderate sensitivity and low prevalence of fetal death, the prediction performance based on ultrasound alone is suboptimal. Future studies that combine maternal risk factors, placental biomarkers, and fetal growth velocity in pregnancy to predict stillbirth are warranted.