Abstract
The aim of this study was to observe the effects of incorporation into an intrauterine contraceptive device (IUCD), either separately or in combination, of medroxyprogesterone acetate (MPA), a progestogen (PG), and indomethacin on the retention rate of the devices in rats. 4 groups of 5 adult Wistar rats were checked for regular estrus cycles by daily vaginal smears. IUCDs were prepared so as to contain 40 mg indomethacin, 20 mg indomethacin with 20 mg MPA, or 40 mg MPA. 1 rat died during injection of the device and a further 4 at laparotomy. The results support the view that PG-synthetase inhibition is effective in reducing myometrial spasm. The Progestasert has markedly lower expulsion rates than plain devices; however, the nonsteroidal anti-inflammatory drug is the most effective in this study. Indomethacin and MPA are effective in increasing retention rates of IUCDs in the rat over a 3 week period of time.