Association of Lewis blood group phenotype with preterm premature rupture of membranes

OBJECTIVE: To evaluate the distribution of Lewis blood group phenotype and secretor status among women with preterm premature rupture of membranes. METHODS: ABO and Lewis blood group phenotypes were determined in 20 consecutive women with preterm premature rupture of membranes. The control group was composed of 48 women from our database without known history of preterm delivery. RESULTS: Of the 20 patients with preterm premature rupture of membranes six had blood type A (30%), nine type B (45%), two type AB (10%), three type O (15%), three Le(a(-)b(+)) (15%), one Le(a(+)b(-)) (5%), and 17 had Le(a(-)b(-)) (80%). Of the 48 controls, 18 had blood type A (37.5%), 10 type B (20.9%), two type AB (4.1%), 18 type O (37.5%), 37 Le(a(-)b(+)) (77.1%), six Le(a(+)b(-)) (12.5%), and five had Le(a(-)b(-)) (10.4%). The difference in the proportions of the A, B, AB, and O phenotypes between the groups was not statistically significant. The distribution of ABO and Lewis phenotype in the control group was similar to that in the general population. The proportion of combined recessive and nonsecretor phenotypes Le(a(+/-)b(-)) between patients with preterm premature rupture of membranes (17 of 20, 85%) and controls (11 of 48, 22.9%) was statistically significant (P <.001). CONCLUSIONS: Women with the Le(a(-)b(+)) phenotype who do secrete Le(b) antigen may have a protective effect against preterm premature rupture of membranes.