THE OVINE FETAL SYMPATHOADRENAL RESPONSE TO THE MATERNAL ADMINISTRATION OF METHAMPHETAMINE

OBJECTIVE: We hypothesized that maternally administered methamphetamin e would alter fetal sympathoadrenal activity. STUDY DESIGN: Six chroni cally catheterized near-term pregnant ewes received an intravenous bol us injection of methamphetamine (1.25 mg/kg). Maternal and fetal arter ial blood gas values, glucose, insulin, lactate, and catecholamines we re measured in the control period and at 15, 30, 60, 90, 120, and 180 minutes after methamphetamine. RESULTS: Fetal P-O2 decreased from 21.4 +/- 1.9 mm Hg at control measurement to 15.3 +/- 3.3 mm Hg after 60 m inutes (p < 0.05). Fetal pH declined from 7.35 +/- 0.014 at control to 7.29 +/- 0.024 after 180 minutes. Fetal plasma glucose rose from 15.3 +/- 2.4 mg/dl at control to peak at 51.2 +/- 6.8 mg/dl at 120 minutes . Insulin levels increased from a control of 40.5 +/- 8.06 to a peak o f 128 +/- 46 mu lU/ml at 180 minutes (p < 0.05). Lactate levels increa sed from a baseline of 33.5 +/- 2.0 mg/dl to 92.3 +/- 22.8 mg/dl at 18 0 minutes. Fetal catecholamines rose from a baseline of 153 +/- 20.2 p g/ml for epinephrine and 226 +/- 18.5 pg/ml for norepinephrine to maxi mum values of 518 +/- 87.3 and 661 +/- 59.3 pg/ml at 15 minutes (p < 0 .05), declining thereafter. CONCLUSIONS: Maternal administration of me thamphetamine is associated with a short-term increase in circulating fetal catecholamines followed by hyperglycemia, lactacidemia, and hype rinsulinemia. These findings suggest that the alteration of fetal symp athoadrenal activity may contribute to the various perinatal complicat ions associated with methamphetamine use.