Reproductive evaluations in female rat offspring exposed to metformin during intrauterine and intrauterine/lactational periods.

Metformin (MET) is a widely-used drug for the treatment of type 2 diabetes mellitus and gestational diabetes. It is known that metformin crosses the placenta and can to be transferred through milk. In vitro studies show that MET decreases gonadotropin-releasing hormone and gonadotropins release in rat neurons, and decreases progesterone and estradiol in rat granulosa cells and androstenedione synthesis in human theca cells.

In utero and lactational exposure to metformin induces reproductive alterations in male rat offspring.

Metformin (MET) is prescribed for the treatment of type 2 diabetes mellitus and gestational diabetes. Although MET crosses the placenta, it is considered safe throughout gestation. However, it has been shown in humans that maternal exposure to MET increases sex hormone binding globulin levels in newborns, and in rats it decreases the testosterone concentration at gestational day (GD) 16.