Physiological range of human chorionic gonadotropin for support of early human pregnancy.
OBJECTIVE: To determine the physiological range of hCG in early pregnancy. DESIGN: Retrospective study of patient charts. SETTING: Magee-Women's Hospital IVF clinic, Monroeville, Pennsylvania. PATIENT(S): Sixty patients with successful, singleton birth outcomes. INTERVENTION(S): Serum hCG measurements on days 12-16 post-oocyte retrieval (OR). MAIN OUTCOME MEASURE(S): Lowest values, highest values, mean values, quartile mean values, and 48-hour doubling times for days 12-16 post-OR. RESULT(S): The average production of hCG in successful pregnancies is roughly 4-fold greater than the lowest amount observed in successful pregnancies, suggesting that a considerable excess of hCG is normally produced. Additionally, the average doubling time is almost 2-fold greater than the slowest doubling rate. CONCLUSION(S): The data from this study provide a set of values for the minimum and maximum threshold of hCG for days 12-16 post-OR that may be physiologically required, although not entirely predictive, for a successful IVF pregnancy outcome.