The intra-uterine contraceptive device--contraceptive or abortifacient?

Further to the investigation of the possible mode of action of the intra-uterine contraceptive device (IUCD), an assay for the beta-specific subunit of human chorionic gonadotrophin (HCG) has detected endogenous chorionic activity 21 days after menstruation. In 22 proven ovulatory cycles, 7 patients wearing an IUCD had demonstrable serum HCG levels in 45% of these cycles. Abnormal menstruation was associated with the majority of cycles in which there was HCG in the serum. Subsequent luteolysis occurred in all cases. The results of this study may support the hypothesis that IUCD exerts its effect on the fertilized, implanted blastocyst, thus causing possible 'micro-abortion'. Caution should be exercised in the interpretation of HCG values in the follow-up of patients with hydatidiform mole or choriocarcinoma who are bearing IUCDs, since positive HCG levels may be due to an early, fertilized and implanted blastocyst and not to invasive tissue.