Effects of maternal oral salbutamol therapy on neonatal endocrine status at birth.

Cord blood concentrations of insulin, growth hormone (GH), triiodothyronine (T3), thyroxine (T4), and thyroid-stimulating hormone (TSH) from 20 patients treated with oral salbutamol were compared with those of 18 matched patients who had not received any betamimetic agents. No significant difference was found in circulating insulin, T3, T4, and TSH between both groups. However, GH levels were significantly higher in the treated group (36.5 +/- 17.4 ng/mL) than in the control group (17.4 +/- 6.6 ng/mL; P less than .001). The unexpected increase in GH levels in the treated group could reflect either fluctuating fetal blood glucose in response to episodic betamimetic administration or direct fetal pituitary production through adrenergic stimulation.