Percent frequencies were as follows: blood group O, 58.49%; A, 31.40%; B, 8.40%; AB, 1.71%; RhD, 95.36%; and RhD negative, 4.64%. Genic frequencies were: i, 0.7648; IA, 0.1821; IB, 0.0519; D, 0.7845; and d, 0.2155, respectively. Incompatibilities between couples and mother-child were 0.3023 and 0.1685 for ABO, 0.0442 and 0.0364 for RhD, and 0.0134 and 0.0061 for double incompatibility, respectively. The probability of maternal alloimmunization was estimated at 0.0309.
Source: Blood group frequencies and ABO and RhD incompatibilities in La Paz, Baja California Sur, Mexico.
ABO and Rho (D) blood groups were studied in 61,023 people receiving medical care at the medical units or blood banks of the Instituto Mexicano del Seguro Social in the metropolitan area in the city of Monterrey, Nuevo León, so as to determine the genetical inheritance patterns that control these blood antigens, and that were used in the stimation of ABO and Rho (D) incompatibility in married couples and in births with maternal fetal incompatibility. It was found that IMSS populations, regardless of the medical units, can be considered as part of the same one and are different to those observed in blood banks. From the married couples, 28.58 percent were found to be incompatible with ABO and 7.15 percent with Rho (D); in 2.04 percent of cases, maternal fetal incompatibility had a ratio of 15.63 percent in the ABO group and 5.60 percent in the Rho (D) group. Double incompatibility was found in 0.88 percent of cases. The importance of these facts is stressed, considered as significant data for neonatologists and for those working in maternal fetal isoimmunization clinics.