Adverse outcomes after preterm labor are associated with tumor necrosis factor-α polymorphism -863, but not -308, in mother-infant pairs

Two single-base polymorphisms of the tumor necrosis factor-α gene (TNF-α) at positions -863 and -308 are associated with variation in production of TNF-α (TNF-α). TNF-α genotypes were tested for association with adverse outcomes in mother-infant pairs with preterm labor. We analyzed a cohort of 118 mother-infant pairs with preterm labor before 34 weeks' gestation. Polymerase chain reaction was used on extracted deoxyribonucleic acid for polymorphism assay. Outcomes included amniotic fluid TNF-α concentration, histologic chorioamnionitis, delivery gestational age, and composite neonatal morbidity. Statistical significance was determined by χ ² and Kruskal-Wallis analysis of variance. Mothers homozygous for the -863 polymorphism (AA) had significantly earlier deliveries (P =. 02), more chorioamnionitis (P =. 03), and greater composite neonatal morbidity (P =. 03). Neither maternal nor fetal carriage of the -308 polymorphism was associated with adverse outcome. In women with preterm labor before 34 weeks' gestation, maternal homozygous carriage of the -863 polymorphism may be associated with preterm delivery and adverse neonatal outcome.