Maternal/newborn GSTT1 null genotype contributes to risk of preterm, low birthweight infants.

Objectives: Maternal cigarette smoke exposure during pregnancy has been identified as a risk factor for prematurity and low birthweight. However, little is known about genetic susceptibility and possible interactions with cigarette smoking which may increase risk of these events.

Methods: Maternal peripheral and umbilical cord blood samples from 955 mother/newborn pairs were genotyped for a panel of phase I/II metabolic enzymes responsible for the metabolism of tobacco related mutagens and carcinogens in order to evaluate the association with premature birth.

Results: As reported previously, maternal cigarette smoking during the last trimester was significantly associated with premature birth. In addition, maternal glutathione S-transferase T1 (GSTT1) null genotype also increased risk of premature birth. Risk was further elevated among subjects with the combination of maternal and newborn GSTT1 null genotype with or without maternal cigarette smoke.

Conclusions: These observations suggest that women and/or newborns with the GSTT1 null genotype who are exposed to cigarette smoke during pregnancy are at elevated risk for premature delivery. The ability to identify high-risk women by genotyping has potential for reducing the frequency of premature births, a major public health concern.