Trophoblastic markers in women using intrauterine contraception.

Serum levels of human chorionic gonadotropin (hCG) and pregnancy-specific beta 1-glycoprotein (PSBG) were measured in 214 women using Copper-T200 intrauterine devices (CIUDs). In a cross-sectional study the samples were taken between the 25th and 35th cycle days, 1 sample per cycle. Either trophoblastic marker was detectable in 8 women (3.7%), hCG in 3 (1.4%), PSBG in 7 (3.3%), and both markers together in (0.9%). Normal menstruation-like bleeding ensued in all but 1 woman whose bleeding was delayed by 5 days. Our results suggest that the intrauterine contraceptive device (IUD) prevents pregnancy mainly before significant amounts of trophoblastic products are secreted. Still, the incidence of subclinical abortion based on the demonstration of trophoblastic markers in serum was 7 to 10 times higher than that of established pregnancy in women using a CIUD.