First trimester maternal serum free β human chorionic gonadotrophin and pregnancy associated plasma protein A as predictors of pregnancy complications

Abstract

Objective To examine the value of first trimester maternal serum free β human chorionic gonadotrophin (β hCG) and pregnancy associated plasma protein A (PAPP‐A) as predictors of pregnancy complications. Design Screening study. Setting Antenatal clinics. Population Singleton pregnancies at 10–14 weeks of gestation. Methods Maternal serum free β hCG and PAPP‐A were measured at 10–14 weeks of gestation in 5584 singleton pregnancies. In the 5297 (94.9%) pregnancies with complete follow up free β hCG and PAPP‐A were compared between those with normal outcome and those resulting in miscarriage, spontaneous preterm delivery, pregnancy induced hypertension or fetal growth restriction and in those with pre‐existing or gestational diabetes. Results Maternal serum PAPP‐A increased and β hCG decreased with gestation. The multiple of median maternal serum PAPP‐A was significantly lower in those pregnancies resulting in miscarriage, pregnancy induced hypertension, growth restriction and in those with pre‐existing or gestational diabetes mellitus, but not in those complicated by spontaneous preterm delivery. The level was < 10th centile of the reference range in about 20% of the pregnancies that subsequently resulted in miscarriage or developed pregnancy induced hypertension or growth restriction, and in 27% of those that developed gestational diabetes. Maternal serum free β hCG was < 10th centile of the reference range in about 15% of the pregnancies that subsequently resulted in miscarriage or developed pregnancy induced hypertension or growth restriction, and in 20% of those that developed gestational diabetes. Conclusion Low maternal serum PAPP‐A or β hCG at 10–14 weeks of gestation are associated with subsequent development of pregnancy complications.