Do high fetal catecholamine levels affect heart rate variability and meconium passage during labour ?

To determine the relationship between umbilical arterial catecholamine levels and fetal heart rate variability and meconium passage. A prospective descriptive study was performed. Umbilical artery catecholamine levels were measured in 55 newborns and correlated with fetal heart rate before delivery, umbilical arterial pH, base excess and the presence of meconium-stained liquor. The range of catecholamine levels was enormous, with very high epinephrine or norepinephrine levels in several fetuses. We were unable to demonstrate an association between high catecholamine levels and the presence of normal fetal heart rate variability despite acidaemia. We postulate that high catecholamine levels may inhibit fetal meconium passage.