Methamphetamine, smoking, and gestational hypertension affect norepinephrine levels in umbilical cord tissues

Abstract

Background: These studies were undertaken to determine methamphetamine (METH) and smoking effects on umbilical vascular dynamics and pregnancy outcomes. Materials and Methods: Umbilical cords (54) were collected prospectively at birth, washed of blood, and stored at -80°C. Cords were thawed and lysates prepared, then catecholamine levels quantified with enzyme-linked immunosorbent assay (ELISA). Results: Catecholamine levels in umbilical cords were not associated with maternal or gestational age, gravidity, parity, neonatal or placental weight. Neither smoking nor METH affected dopamine or epinephrine. However, smoking (two-fold) and METH (four-fold) decreased norepinephrine and together a 60-fold reduction occurred (p = 0.025). Cesarean section and hypertension were both associated with lower norepinephrine levels (p < 0.001) regardless of drug status. In normotensive pregnancies, smoking and METH significantly decreased norepinephrine levels (two-fold and 3.5-fold each, respectively) with a 40-fold decrease for METH/smoking together. Discussion: Depletion of norepinephrine by METH and smoking likely contributes to pregnancy complications, including the higher incidence of respiratory distress and postpartum hemorrhage in cesarean section.