First trimester maternal serum free human chorionic gonadotropin as a predictor of adverse pregnancy outcome

The purpose of this study was to evaluate whether abnormal levels of first trimester maternal serum free human chorionic gonadotropin (beta-hCG) are predictive of adverse pregnancy outcomes.

The study included 1,622 consecutive patients with singleton pregnancies who underwent first trimester Down syndrome screening using nuchal translucency, and maternal serum free beta-hCG and pregnancy-associated plasma protein-A. Patients with fetal anomalies or chromosome aberrations were excluded from the study. The incidences of various adverse pregnancy outcomes were evaluated according to maternal serum free beta-hCG levels. Outcome variables included spontaneous miscarriage, proteinuric and non-proteinuric pregnancy-induced hypertension, fetal growth restriction, intrauterine fetal demise, spontaneous preterm delivery, oligohydramnios and placental abruption.

No significant differences were noted between groups for any of the demographic variables. The only statistically significant result was an increase in the relative risk for spontaneous miscarriage (RR = 6.33) at free beta-hCG <0.2 multiples of the medians. No other statistically significant result was noted for the other adverse outcomes or for the overall complication rate.

Low free beta-hCG is associated with a higher incidence of spontaneous miscarriage but is a poor predictor of other pregnancy complications.