Impact of prenatal exposure to testosterone in biometrics and endocrine parameters of newborn lambs

Abstract

Biometric and endocrine parameters were studied in male and female Suffolk Down newborn lambs born to mothers exposed to an excess of testosterone (EPT) during 60 days (EPT-P1) and during 90 days (EPT-P2), beginning at day 30 of pregnancy. Control mothers received vegetable oil. At delivery time the following data were registered: time of delivery, number of newborns per mother and sex of the newborn. At 8 hours postpartum, the characteristics of the genitalia, the anus-urinary meatus distance and body weight were recorded. Blood samples were taken to measure cortisol, T3 and T4 on plasma. Data regarding time of birth, number of offspring and sex did not show any differences between the three groups of newborn lambs. Females born to EPT-P1 and EPT-P2 mothers exhibited masculinized genitalia, showing a penis and an empty scrotum. Females born to EPT-P1 mothers showed lower body weight and lower plasma T4 concentrations than females and males born to the other 2 groups of mothers (P < 0.05). Plasma cortisol concentrations were not different between offspring from the 3 groups of mothers, however, females born to EPT-P1 mothers showed an inverse correlation between cortisol concentration and body weight. Data showed that exposure to testosterone during a critical time during pregnancy had a profound impact on genitalia of females, and depending on the dose it produces lower body weight and lower plasma T4 concentrations in newborn females. The EPT had no effect on biometric and endocrine parameters in newborn male lambs.