The action of anti-inflammatory drugs on the fertility of female rats with intrauterine contraceptive devices

Abstract

A silk thread (0-0) or a Cu wire (0.18 mm diameter) was placed in the left uterine horn of rats, at least 3 days before fertilization. The animals were untreated or given daily injections of 3 mg hydrocortisone or 30 mg aspirin beginning the day after insertion of the IUD [intrauterine contraceptive device]; 2 wk after coitus, the animals were killed. A longitudinal (.ltoreq. 10 mm) silk thread and the Cu wire were effective IUD regardless of treatment. With the short silk thread [.ltoreq. 2 mm), implantation occurred in all groups of rats but a high failure rate was observed in hydrocortisone-treated rats (5/9 with implantations). The number of implantations/number of corpora lutea (.apprx. 100) was much higher (20.4%) in rats treated with aspirin and hydrocortisone than in untreated animals (3.2%) (P < 0.01). The effectiveness of an IUD apparently can be altered by treatment with an anti-inflammatory substance.