Early [beta]-HCG levels predict IVF pregnancy viability.(Gynecology)

LOS ANGELES -- Physicians counseling patients after in vitro fertilization can use early [beta]-HCG levels and slopes to predict whether a pregnancy is viable, according to a study presented at the annual meeting of the Society for Gynecologic Investigation.

Researchers in the Center for Reproductive Medicine at New Jersey Medical School, Newark, have identified [beta]-HCG thresholds at 16 and 18 days after oocyte retrieval based on a retrospective chart review of 322 pregnancies by in vitro fertilization.

Investigator Shirley A. Fong, M.D., and her colleagues reported in a poster presentation at the meeting that the new levels were highly significant for distinguishing viable pregnancies from those that did not sustain a fetal heart beat through the first trimester. They also were significantly higher for multiple pregnancies, compared with singleton pregnancies.

"What it puts in my mind is, if their first level is below 100, they are probably not going to have a viable pregnancy outcome.... I know to couch my counseling," Dr. Fong said in an interview.

The investigators reviewed all IVF pregnancies at the New Jersey center from June 1998 to March 2004. A total of 53 patients did not have a fetal heartbeat at the end of the first trimester. Their mean [beta]-HCG levels were 56 mIU/mL on day 16, and 115 mIU/mL on day 18, with an average slope of 24 mIU/mL.

Levels and slopes were much higher for the remaining 269 women with viable pregnancies with mean levels of 216 mIU/mL on day 16 and 505 mIU/mL on day 18, with an average slope of 140 mIU/mL.

Most of the women, 180, had singleton pregnancies. Their average [beta]-HCG levels were 169 mIU/mL on day 16 and 401 mIU/mL on day 18. The researchers noted that the average slope of 111 mIU/mL was 4.62 times higher than in the pregnancies that were not viable.