Risk of Bronchopulmonary Dysplasia by Second Trimester Maternal Serum Levels of Alpha-fetoprotein, Human Chorionic Gonadotrophin, and Unconjugated Estriol

Although maternal serum alpha-fetoprotein (AFP), human chorionic gonandotrophin (hCG), and estriol play important roles in immunomodulation and immunoregulation during pregnancy, their relationship to the development of bronchopulmonary dysplasia (BPD) in young infants is unknown despite BPD being associated with pre- and postnatal inflammatory factors. The objective of this population-based study was to examine whether second trimester levels of AFP, hCG, and unconjugated estriol (uE3) were associated with an increased risk of BPD. We found that these serum biomarkers were associated with an increased risk of BPD. Risks were especially high when AFP and/or hCG levels were above the 95(th) percentile and/or when uE3 levels were below the 5(th) percentile (relative risks (RRs) 3.1 to 6.7). Risks increased substantially when two or more biomarker risks were present (RRs 9.9 to 75.9). Data suggested that pregnancies which had a biomarker risk and yielded an offspring with BPD were more likely to have other factors present that suggested early intrauterine fetal adaptation to a stress including maternal hypertension and asymmetric growth restriction.