Implication of ABO Blood Type on Ovarian Reserve in Indian Women

Background: To explore the association between ABO blood type and ovarian reserve, as reflected by early follicular phase follicle stimulating hormone (FSH) levels. Materials and methods: In this cross-sectional observational study, early follicular phase (day 3) serum levels of FSH (IU/L) and information on blood types (O, A, B, AB), patient age, and body mass index (BMI) were collected from 300 female patients, who were undergoing fertility evaluation at Vydehi Institute of Medical Sciences and Research Centre (VIMS & RC), Bengaluru. Serum FSH > 10 IU/L was taken as a measure of decreased ovarian reserve (DOR). Data distribution for FSH, age, BMI were analyzed and nonparametric tests were used for comparison across blood groups. Pearson’s correlation test was used to determine the relationship between elevated FSH and blood types after adjusting for age and BMI. Results: Proportions of blood types O, A, B, and AB were 42, 24.3, 28.7, and 5% respectively. Mean age (years) and BMI (kg/m2) among study group were 34.08 ± 3.48 and 24.34 ± 2.56 respectively. Out of 300 women, 240 women had serum FSH < 10 IU/L and 60 women had serum FSH > 10 IU/L. Women with blood type “O” (32 out of 60) were twice as likely to exhibit FSH > 10 IU/L (p = 0.02) compared to “A” and “B” blood type. Conclusion: Our results have shown that there is an association between ABO blood type and DOR among Indian women. Blood group “O” appears to be associated with DOR that is independent of advancing age and BMI.