Levonorgestrel is one of the contraceptives used by women during lactation. Previous studies have shown that the administration of levonorgestrel to lactating female rats has affected the offspring, causing puberty delay in males and alterations on uterus and oviduct weight.PURPOSE: To study the reproductive capacity of F1 females from rats treated with levonorgestrel.METHODS: Female Wistar rats were treated with levonorgestrel (0.030 mg/1 ml of distilled water) from day 7 to day 13 after birth (day 1 = birth). On day 90 F1 females were mated with fertile males and insemination was confirmed by the presence of spermatozoa in the vaginal smear (first day of pregnancy). Inseminated females were distributed in three groups of 20 animals each (10 F1 control and 10 F1 treated). The animals were killed on days 2, 4 and 5 after insemination by ether overdose inhalation and the ovaries, oviducts and uterine cornua were removed. The ovaries were weighed and the corpora lutea counted. Oviducts and corpora lutea were washed with saline solution and the pre-embryos were counted and examined in all segments.RESULTS: The ovaries weight, the number of corpora lutea, the number and development phase of the pre-embryos were similar in both groups.CONCLUSION: In the experimental model used, F1 females whose mothers were treated with levonorgestrel during lactation, did not show any alteration in their reproductive capacity.
Levonorgestrel; Lactation; Rats; Reproduction
