Table 3: Studies on the Association Between ABO Blood Groups and Placental Malaria

Table S1: Studies on the association between ABO blood groups and placental malaria

Loscertales et al. Senga et al. Adam et al. Malaria J. Adam et al. J. Parasit (study Present study (study listed here, but not only listed here, not included included into Forest plot as into comparisons) meta analysis focused on holoendemic settings Study 09/1967-05/1968 02-06/04, 01-07/05 10/06-03/07 11/07-01/08 period Setting Banjul and Kombo-St Mary Chikwawa District, Southern New Halfa teaching Hospital, Gadarif Hospital, eastern Lambaréné/ Gabon, perennial District of Gambia, seasonal Malawi, highly endemic Eastern Sudan. Low malaria Sudan malaria transmission, EOR malaria transmission, peak perennial malaria transmission Unstable malaria transmission ≈50 infective bites per person after rainy season ( July- Oct.) transmission. year at risk. Declared To describe the association To confirm associations To investigate the epidemio- To determine the prevalence, To investigate the association objectives between AB0 phenotypes, between AB0 phenotypes, pathological characteristics of and evaluate the risk factors, between the ABO blood placental malaria and placental malaria and placental malaria with special of placental malaria groups and active placental pregnancy outcomes pregnancy outcomes attention to blood-groups. malaria Analysis 198 mothers, 89 (45%) 647 mothers, 206 (32%) 293 mothers, 114 (40%) 236 mothers, 111 (47%) 378 mothers, 84 (22%) population primiparae, active placental primiparae, active placental primiparae, active placental primiparae, active placental primiparae, active placental malaria in 74 (37%) malaria in 124 (19%) malaria in 12 (4%), past malaria in 18 (7.6%), past placental infection in 82 (, placental infection in 28 28%) (11.9%) Main ABO-blood group 0 vs. other ABO-blood group 0 vs. other ABO-blood group 0 vs. other “Risk factors” for placental ABO-blood group 0 vs. other exposure malaria Main Active placental malaria Active placental malaria Past placental malaria (for the Past, acute & chronic Active placental malaria Outcome comparison here active placental malaria (for the placental malaria was used) comparison here active placental malaria was used) Findings Blood group 0 associated with Blood group 0 associated with Blood group 0 associated with No significant association Blood group 0 (non- - a lower risk of active - a lower risk of active - a higher risk of past between Blood group 0 and significantly) associated with placental malaria infection in placental malaria infection in placental malaria infection in placental infection (OR 0.8, a higher risk of active multiparae (OR 0.5, 95% CI multiparae (OR 0.6, 95% CI all (OR 1.9, 95% CI 1.1-3.2). 95% CI 0.4-1.1). Main risk placental malaria infection 0.2-1.0) 0.4-1.0) - a higher risk of past factor for placental infection independently of the parity - a higher risk of active - a higher risk of active placental malaria infection in was lack of prenatal care status (Combined OR 0.6, placental malaria infection in placental malaria infection in primiparae (OR 2.6, 95% CI 95% CI 0.3-1.3) primiparae (OR 3.0, 95% CI primiparae (OR 2.2, 95% CI 1.1-6.5). 1.2-7.3) 1.2-4.6)