Long-term adverse effects on reproductive function in male rats exposed prenatally to the glucocorticoid betamethasone

Betamethasone is the drug of choice for antenatal treatment, promoting fetal lung maturation, decreasing the incidence of respiratory distress syndrome and neonatal mortality. Previous studies reported that prenatal treatment with this drug reduced testosterone levels, sperm quality and fertility in adult rats. We aimed to further evaluate the reproductive consequences of prenatal betamethasone exposure in male rats. Pregnant Wistar rats (n = 13/group) were separated into two groups: control (vehicle) and betamethasone- treated (0.1 mg/kg IM) and rats were injected on gestational days 12, 13, 18 and 19. Body weight, sexual behavior, reproductive organ weights, serum hormone levels, accessory glands contractility, sperm parameters, and fertility after in utero artificial insemination were evaluated. Our results showed that prenatal betamethasone exposure provoked a significant reduction in body weight at PND 01 and, at adulthood, decrease in FSH levels, sperm motility and production. Furthermore, seminal vesicle weight was decreased while testicular and ventral prostate weights were increased. Serum LH levels and the percentage of abnormal sperm were significantly increased. Although sexual behavior was not altered, a significant reduction in fertility in the adult rats exposed prenatally to betamethasone was noted. We concluded that prenatal betamethasone exposure leads to long-term reproductive impairment in male rats. These results may have important implications for humans, considering the use of this glucocorticoid in pregnant women.