Circulating Delta-like homolog 1 (DLK1) at 36 weeks is correlated with birthweight and is of placental origin

Abstract Introduction Recently, Delta-like homolog 1 (DLK1) was identified as a potential marker of small-for-gestational-age (SGA; Methods The Fetal Longitudinal Assessment of Growth (FLAG) study was a prospective blood collection from 2000 women. We assessed a case-control cohort at 28 and 36 weeks from the first 1000 FLAG women, before validating changes in the entire second 1000. A subgroup of FLAG participants underwent ultrasound examinations, and 137 neonates, body composition assessment (PEAPOD). DLK1 secretion was assessed from human placentas ex vivo. Results Circulating DLK1 was significantly reduced at 28 and 36 weeks’ gestation in women destined to deliver a SGA fetus and associated with birthweight centile (n = 999, p  Conclusion We confirmed circulating DLK1 is reduced at both 28 and 36 weeks’ gestation preceding delivery of a SGA infant, shown that it is not significantly associated with clinical measures of placental insufficiency, and provide new data demonstrating it may be placenta-derived in humans.