Fetal gender and cocaine exposure as determinants of cord blood gamma-glutamyl transferase activity

Abstract

Objective: The serum activity of the hepatic enzyme gamma glutamyl transferase (GGT) is elevated in the newborn relative to older age groups. Few reports to date have studied the influence of perinatal factors on neonatal serum GGT and no study has assessed the influence of maternal drug ingestion. Study Design: Cord blood was randomly collected from 234 liveborn infants and correlated with a range of maternal and fetal perinatal variables to assess influences on cord blood GGT. Results: Our study showed that the range of cord blood GGT activity in 234 randomly selected term newborns was 22 to 556 IU/1. In a subgroup of 75 newborns, GGT activity was independently influenced by only two of the variables studied - cocaine exposure and fetal gender (p=0.009, r=0.39). Females had a lower GGT than males (95±66 vs 130±90 IU/1, p<0.001) while GGT activity in cocaine-exposed newborns was lower than in cocaine-nonexposed newborns (96±48 vs 142±109, p<0.01). Birth weight, race, gestational age, and maternal serum GGT were not found to significantly influence cord blood GGT activity. Maternal GGT was uniformly normal and was not affected by any of the variables tested. Conclusion: Our findings demonstrate that the reference range for cord blood GGT activity is wide and appears to be influenced by fetal gender and cocaine exposure.