Quinacrine sterilization: an assessment of risks for ectopic pregnancy, birth defects and cancer.

Quinacrine sterilization (QS) involves transcervical insertion of quinacrine pellets using a modified Copper TIUD inserter. Pellets are placed at the fundus in the proliferative phase of the menstrual cycle. Efficacy is presently estimated at 1 pregnancy failure per 100 women at 2 years. Early complications are lower for QS than surgical sterilization and this is also true for risk of ectopic pregnancy with newer insertion protocols. The risk of birth defects is very low, when estimated from a model with reasonable assumptions for probability of insertion in a pregnant uterus or within 30 days of conception, probability of such exposed pregnancy being carried to term, and probability of quinacrine exposure to the fetus causing a birth defect. Although quinacrine is a mutagen it is unlikely to be a carcinogen. Concentrations of quinacrine in the uterus after transcervical insertion are higher than for oral administration for only a matter of a few hours, although this brief exposure is adequate to cause injury to the tubal epithelium, leading to inflammation and an occluding scar. Oral administration of quinacrine is accepted as non-carcinogenic. Each site of use of QS must make its own risk/benefit assessment. The benefits of any contraceptive that can raise contraceptive prevalence is greatest for developing countries.