Objective: Increased amniotic fluid concentrations of tumor necrosis factor-alpha are observed in women with preterm labor and subsequent preterm birth. We tested whether a mutation in the promoter region of tumor necrosis factor-alpha gene, TNF T2, which increases transcription of the gene, is more frequent in a preterm delivery cohort.
Study design: Deoxyribonucleic acid was extracted from whole blood of 203 women and 44 fetuses delivered at < 37 weeks of estimated gestational age. The polymerase chain reaction was used to amplify the promoter region of the tumor necrosis factor-alpha gene. The resulting polymerase chain product was subjected to allele-specific enzymatic digestion with Nco I. Fragments were size fractionated on a 3% Metaphor agarose gel stained with ethidium bromide. Results were analyzed with use of a chi 2 contingency table.
Results: No statistically significant differences for either the TNF T1 or TNF T2 allele frequencies were found between women or fetuses delivered preterm compared with a control group or previously published allele frequencies.
Conclusions: The frequency of this tumor necrosis factor-alpha promoter mutation, TNF T2, is not increased in either women or fetuses delivered at < 37 weeks' gestation. Basal levels of tumor necrosis factor-alpha are unlikely to affect a woman's risk of preterm delivery. Tumor necrosis factor-alpha variants should not be used as a predictive test for preterm delivery.