What is Free Beta Human Chorionic Gonadotrophin (Free B HCG)

The purpose of this study was to evaluate whether abnormal levels of first trimester maternal serum free human chorionic gonadotropin (?-hCG) are predictive of adverse pregnancy outcomes. Methods: The study included 1,622 consecutive patients with singleton pregnancies who underwent first trimester Down syndrome screening using nuchal translucency, and maternal serum free ?-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 ?-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. Results: 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 ?-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. Conclusion: Low free ?-hCG is associated with a higher incidence of spontaneous miscarriage but is a poor predictor of other pregnancy complications.