Association between the PAI-1 4G/5G promoter polymorphism and recurrent miscarriage

One of the factors known to cause thrombophilia in women with unexplained recurrent spontaneous abortion (RSA) is the 4G/5G polymorphisms in the promoter region of the plasminogen activator inhibitor-1(PAI-1). This study aimed to determine the association between RSA and this polymorphism in Iranian patients. In this case-control study, 30 patients with the background of two or more consecutive unexplained abortions and 10 women with at least two live births without a miscarriage who referred to Baqiyatallah hospital and Avicenna Infertility Clinic were analyzed for the PAI-1 4G/5G promoter polymorphism by the PCR-RFLP method. Results achieved from estimating the genotype of this polymorphism were analyzed by the SPSS16 and Chi Square. 4G allele frequency was 46.7 % in the patient group and 40% in the control group. Frequency of the PAI-1 4G/5G promoter polymorphism was 76.7% in patients and 80% in controls. For PAI-1 4G/5G promoter polymorphism, 60% of patients and 80% of controls were heterozygote. Furthermore, 16.7% of patients were homozygote, though there were not any homozygote in controls. These findings failed to support the relationship between PAI-1 4G/5G promoter polymorphism and the increasing risk of RSA in evaluated Iranian women.