Human chorionic gonadotropin as a predictor of outcome in assisted reproductive technology pregnancies.

OBJECTIVE

To determine whether serum hCG and progesterone levels obtained 16 days after ovulation are reliable predictors of pregnancy outcome.

DESIGN

A retrospective study.

SETTING

The data were obtained from two integrated Adelaide-based clinics: the Queen Elizabeth Hospital and Wakefield Clinic.

PATIENT(S): Women who have achieved a pregnancy through ART treatment.

MAIN OUTCOME MEASURE(S): Analysis of data using logistic regression (STATA v.5.0) to predict a binary outcome: ongoing pregnancy or miscarriage. Ongoing pregnancy was defined as progression to >20 weeks' gestation. Miscarriage included spontaneous abortion, biochemical and ectopic pregnancies, and blighted ovum.

RESULT(S): Human chorionic gonadotropin was found to be the main determinant of ongoing pregnancy. Age and progesterone had minor effects, whereas stimulation, luteal support, and treatment types were nonpredictive. Low hCG levels between 25 and 50 IU/L are associated with a low probability of ongoing pregnancy (<35%), whereas levels of >500 IU/L predict a >95% chance of ongoing pregnancy.

CONCLUSION(S): A single serum hCG level 16 days after ovulation provides a useful predictor of pregnancy outcome.