Correlation of 2-methoxyestradiol levels in cord blood and complications of prematurity.

2-methoxyestradiol (2ME2) is a potent antiangiogenic molecule that inhibits the expression of hypoxia-inducible factor (HIF)-1alpha and, consequently, of VEGF and other HIF-1alpha target genes. Although 2ME2 is elevated during pregnancy in maternal serum, its presence in fetal fluids and its impact in neonatal health are unknown. In this study, we 1) described normal levels of 2ME2 in maternal blood, cord blood, breast milk, and amniotic fluid, and 2) compared a composite measure of perinatal outcome between infants born with high and low levels of 2ME2. We found that 2ME2 was significantly decreased in all fluids compared with prepartum maternal serum. After stratifying babies by 2ME2 exposure levels, we observed no differences in the vulnerability to impaired lung development or to complications involving aberrant angiogenesis or vascular leak, such as necrotizing enterocolitis (NEC), intraventricular hemorrhage (IVH), posthemorrhagic hydrocephalus (PHH), and retinopathy of prematurity (ROP). In summary, fetal 2ME2 concentrations do not appear to affect neonatal outcome.