Umbilical cord plasma levels of growth-arrest specific protein 6 in intrauterine growth restriction

Abstract Objective. Growth arrest specific protein 6 (GAS6) is a newly discovered antiapoptotic protein related to cell survival. We hypothesized that GAS6 might be involved in the fetal adaptation to intrauterine growth restriction (IUGR). Design. A nested case-control study. Setting. A retrospective study of 25 small-for-gestational age and 36 appropriate-for-gestational age pregnancies. Sample. Frozen samples from cases and controls in a prospective cohort study. Methods. GAS6 was measured with an enzyme-linked immunosorbent assay method in umbilical cord plasma taken immediately after delivery. Main outcome measure. Differences in GAS6 levels between pregnancies with placental insufficiency and those without. Results. GAS6 levels were significantly higher among newborns with abnormal umbilical cord Doppler tracings (19.5 ± 5.3 vs. 15.0 ± 3.2, p = 0.02). Among those with abnormal umbilical cord tracings (n = 9), the two with umbilical venous pulsations had significantly lower GAS6 levels (mean 14.4 vs. 21.1, p = 0.04) and one of them died after delivery. Conclusions. GAS6 levels are raised in IUGR fetuses and we speculate that GAS6 might be involved in the fetal adaptation to placental insufficiency.