OBJECTIVETo investigate the relationship between a single nucleotide insertion/deletion(4G/5G) polymorphism located in the promoter region of the plasminogen activator inhibitor-1(PAI-1) gene and the pathogenesis of pregnancy-induced hypertension syndrome(PIHs).

METHODSThe 4G/5G polymorphism of PAI-1 gene in 171 PIHs patients (PIHs group) and that in 193 normal pregnant women (control group) were detected by a combination of polymerase chain reaction-restriction fragment length polymorphism.

RESULTS(1)The genotype frequencies of PAI-1 gene in PIHs group were 47.4% for 4G/4G, 41.5% for 4G/5G, and 11.1% for 5G/5G. The 4G/4G genotype and 4G allele frequencies of PAI-1 gene(47.4% and 0.681) for PIHs patients were higher than those (21.2% and 0.495) for normal controls respectively (P<0.001). (2)Both the 4G/4G genotype and the 4G allele of PAI-1 gene occurred more frequently in the severe PIHs group(61.3% and 0.758) than those (35.8% and 0.623) in the mild PIHs group respectively (P<0.001). However, there were no significant differences between those in mild group (35.8% and 0.623) and moderate group(42.8% and 0.625) respectively. (3) The 4G/4G genotype was significantly associated with PIHs (OR=3.34, 95%CI: 2.14-5.22).

CONCLUSIONThese findings suggested that PAI-1 gene polymorphism may be a susceptible factor to the pathogenesis of PIHs and the 4G/4G genotype may be one of the major risk factors for PIHs in pregnant women.