Objective: To describe prostanoid DP receptor (PTGDR) variants in women with preterm births who admitted to coital activity (CA) within 24 h of labor.
Study design: To achieve >80% statistical power, a pilot case-control study compared 24 premature births from mothers with CA (Group 1), 30 mothers of premature infants who did not have CA (Group 2 non-coital activity) and 95 non-coital activity mothers with term births (Group 3 controls). Four functional PTDGR single nucleotide polymorphisms (SNPs) were evaluated: T-549C, C-441/T, T-197C and G+1044A. PHASE 2.0.2 and SAS 9.2 were used for analysis.
Result: All SNPs were in Hardy-Weinberg equilibrium in controls. The C-441/T genotype frequency was significantly increased among Group 1 women relative to Group 2 and 3 women (odds ratio (OR): 30.1, 95% confidence interval (CI) 6.9-191 and 25.7 95%CI 25.7-not computible, respectively). Of the possible haplotypes among the groups, the TCTG haplotype (T-549C, C-441/T, T-197C and G+1044A) was significantly more frequent in Group 1 women compared with the control groups (OR 53.4, 95%CI 10.3-554.8).
Conclusions: A differential genomic pattern of PTGDR polymorphisms was identified in a sub-set of mothers which was associated with an increased risk of post-coital preterm birth.