Effect of gestogens on lactation maintenance in the albino rat.

6 groups of 8 primiparous Wistar albino rats each were investigated to determine the effects of different contraceptives on lactation. There was a marked drop in lactation efficiency index (76.2% to 45.8%) in 3 of the medicated groups. The growth rate of the litters of treated mothers was found to be much lower than that of control litters. These results agree well and confirm the previous findings that administration of contraceptives to lactating humans and goats induced an adverse effect on their lactation performance. It is suggested that high levels of circulating estrogens tend to inhibit lactation even in the presence of the ovary.