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

Abstract

OBJETIVO: investigar a associação entre o polimorfismo do gene do receptor da progesterona (PROGINS) e o risco de parto prematuro. MÉTODOS: estudo caso-controle, para o qual foram selecionadas 57 pacientes com antecedente de parto prematuro (Grupo Caso) e 57 pacientes com parto a termo na gravidez atual e sem antecedentes de parto prematuro (Grupo Controle). Foi realizada a coleta de 10 mL de sangue por venopunção de veia periférica para extração de DNA. As genotipagens foram feitas por reação em cadeia de polimerase (PCR) nas condições de ciclagem específicas para o polimorfismo em estudo seguida de eletroforese em gel de agarose a 2%. Foram determinados três genótipos: selvagem (T1/T1), heterozigoto (T1/T2) e mutado (T2/T2). As frequências genotípicas e alélicas dos dois grupos foram comparadas pelo teste do χ² adotando-se, com o nível de significância, valor pPURPOSE: 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.

Keywords

• Gravidez de alto risco
• Trabalho de parto prematuro
• Receptores de progesterona
• Polimorfismo genético
• Pregnancy, high-risk
• Obstetric labor, premature
• Receptors, progesterone
• Polymorphism, genetic