[The progesterone receptor gene polymorphism as factor of risk for the preterm delivery]. / Polimorfismo do receptor de progesterona como fator de risco para o parto prematuro.

ABSTRACT

PURPOSE: to investigate the association between gene polymorphism of the progesterone receptor (PROGINS) and the risk of premature birth. METHODS: In this case-control study, 57 women with previous premature delivery (Case Group) and 57 patients with delivery at term in the current pregnancy and no history of preterm delivery (Control Group) were selected. A 10 mL amount of peripheral blood was collected by venipuncture and genomic DNA was extracted followed by the polymerase chain reaction (PCR) under specific conditions for this polymorphism and 2% agarose gel electrophoresis. The bands were visualized with an ultraviolet light transilluminator. Genotype and allele PROGINS frequencies were compared between the two groups by the χ2 test, with the level of significance set at value p < 0.05. The Odds Ratio (OR) was also used, with 95% confidence intervals. RESULTS: PROGINS genotypic frequencies were 75.4% T1/T1, 22.8% T1/T2 and 1.8% T2/T2 in the Group with Preterm Delivery and 80.7% T1/T1, 19.3% T1/T2 and 0% T2/T2 in the term Delivery Group. There were no differences between groups when genotype and allele frequencies were analyzed p = 0.4 (OR = 0.7) and p = 0.4 (OR = 0.7). CONCLUSIONS: the present study suggests that the presence of PROGINS polymorphism in our population does not constitute a risk factor for premature birth.