Low hCG Levels Predict Early Miscarriage

Low levels of human chorionic gonadotrophin (hCG) in early pregnancy are associated with spontaneous miscarriage, study findings suggest.

Stephen Tong and colleagues from Monash University in Victoria, Australia, retrospectively studied 1054 women undergoing IVF. Participants were divided into three groups according to their hCG levels on day 16 after conception.

The overall miscarriage rate was 11.1 percent, and the median gestational age at miscarriage was 10 weeks and 4 days, Tong et al report.

They found that median day-16 hCG levels were significantly lower in women who subsequently miscarried than in those who had an ongoing pregnancy (182 vs 223 mIU/ml).

Furthermore, hCG levels were inversely correlated with the risk of pregnancy loss. The miscarriage rate was 8.0 percent for women above the 75th percentile, 9.9 percent for those between the 25th and 75th percentile, and 16.7 percent for those below the 25th percentile. This trend was highly statistically significant.

Tong et al conclude that low hCG levels in very early pregnancy are associated with an increased risk of miscarriage, adding: "The mechanisms underlying late first-trimester and second-trimester miscarriages may have begun as early as the first week of implantation."

Obstetrics & Gynecology 2006; 107: 300-4

Posted: 22 February 2006