Effects into adulthood of single or repeated antenatal corticosteroids in sheep

To determine effects of maternal or fetal injections of betamethasone on postnatal growth and arterial pressure.

We measured body weight, arterial pressure, and heart rate serially in sheep born after single or repeated maternal or fetal betamethasone injections. At approximately 3.5 years, organ weights were measured.

Repeated maternal betamethasone injections caused intrauterine growth restriction, and low body weight and blood pressure at 3 months. From 6 months to 3 years, body weight, blood pressure, and heart rate were not affected by treatment. At approximately 3.5 years, brain weight was reduced after single or repeated maternal betamethasone by 13% and 18%, respectively (P = .001). Fetal betamethasone reduced brain weight by 7% to 8% (P = .018). Weights of other organs were not affected by treatment. Brain weight was unrelated to body weight at approximately 3.5 years (P = .649) but was related to birth weight (P = .029).

Prenatal betamethasone does not have long-term effects on blood pressure but causes a persistent deficit in brain weight.