Prolonged Interval Before Conception Following Aglepristone-Induced Abortion In Albino Rats

Abstract

For many years now, the several drugs used as abortifacients in animals have often been associated with severe adverse effects on the general and reproductive health of treated animals. Aglepristone is a recent antiprogestin (progesterone-receptor antagonist) used for the induction of abortion in animals. The goal of this study was to investigate the effect on further fertility after mid-gestation termination of pregnancy with aglepristone in albino rats. Fifteen healthy female, 12-14 weeks old, albino rats (Rattus norvegicus) were used. Group I (n = 7) comprised rats whose pregnancies were terminated mid-gestation (day 11) with a subcutaneous injection of 10 mg/kg b.w. aglepristone. Group II (n = 8) comprised rats which were treated midgestation with sterile water and had normal, spontaneous gestation and parturition. The further fertility of the groups was compared by monitoring the following parameters for two subsequent pregnancies: interval before pregnancy, gestation length, litter size, litter weight at birth, fetal weight at birth and percentage of fetuses alive at birth. A subcutaneous injection of aglepristone caused abortion in 100% of rats in group I. There was a longer (P < 0.05) interval between abortion and pregnancy in the aglepristone-treated group (23.7 ± 6.6 days) than in group II (12.5 ± 2.7 days). However, there were no significant differences (P > 0.05) between the groups when gestation length, litter size, litter weight, fetal weight and percentage of live fetuses were compared. In the subsequent pregnancy, both groups displayed no differences (P > 0.05) in all the reproductive parameters compared. Aglepristone can be used to induce a single instance of mid-gestation abortion without any severe or prolonged adverse effects on the fertility of treated animals. It will be interesting, however, to evaluate the effects on reproduction following prolonged use or repeated induction of abortion with aglepristone.