Hence, further studies must be conducted for a more detailed evaluation of the Rh blood type among pregnant women.Objective: To determine the distribution pattern of ABO and Rhesus blood groups among different ethnic populations in an urban centre. To the best of our knowledge, this is the first nationwide retrospective research about the association between Rh blood type and adverse pregnancy outcomes in Korea. Third, with regard to neonatal outcomes, attention is now shifting towards shortand long-term morbidity however, in this study, only neonatal weight was included, and more detailed data are required to evaluate neonatal outcomes. Second, as described above, the exclusion of multigravida pregnant women might have influenced the relatively varying results of the rates of preeclampsia compared to other previous studies.

However, the differences between the specific Rh blood type or the ABO classification were not assessed because the ABO blood group is not considered a disease category in the KNHI program. First, this study only included Rh blood type classifications. This result might be explained partly by the limitations of our research. However, we did not find any associations between Rh blood type and adverse pregnancy outcomes. In our study, different findings were obtained, which might be attributed to the fact that we did not assess the differences in these antigens. Among these antigens, Rh D, C, c, E, and e were considered the most clinically significant, and Rh D has the strongest antigenicity. In a previous research, more than 50 Rh antigens have been identified at the serological level encoding 2 genes (RHD and RHCE). However, in this study, multiparous women were enrolled, and only the Rh D antigen was evaluated. showed that Rh D-positive mothers had a slightly increased risk of preeclampsia in a large cohort study in Sweden (OR, 1.07, 95% CI, 1.03–1.10). However, there was no significant association between Rh blood type and pregnancy outcomes, even preeclampsia, in primiparous women. Thus, this study evaluated the differences in the rate of cesarean section, preeclampsia, postpartum hemorrhage, abruptio placenta, placenta previa, and uterine artery embolization among pregnant women with different Rh blood types. The clinical characteristics did not differ significantly between Rh-positive (n=1,661,320) and Rh-negative women (n=3,290).Ĭompared to the ABO types, studies about Rh blood type are limited.

Therefore, this study focused on the association between Rh-positive and Rh-negative blood groups and maternal pregnancy outcomes in 1,664,882 primigravida women in a large population study. However, whether Rh blood type (negative or positive) is correlated to pregnancy outcomes is not known. By contrast, another study showed a weak relationship between ABO blood type and gestational hypertension. Currently, a non-O blood group may affect hemostatic balance disturbances and lead to an increased risk of embolization compared to an O blood group. In Korea, Rh-negative is considered a rare blood type according to the Korean Red Cross standards, with an incidence of 0.4% however, pregnancy can lead to several complications among Rh-negative women. In general, Africa, the Middle East, Europe, India, and Central Asia have higher Rh-negative blood rates than other regions. The proportions of blood type differ according to race, region, and ethnicity. The discovery of the Rh blood type has played an important role not only in guiding blood transfusions more scientifically but also in improving experimental diagnoses and clinical immunotherapy. With continuous studies of the Rh blood groups, the Rh blood group system was found to be the most complex system in the RBCs. In 1940, during animal experiments, Landsteiner and other scientists discovered that rhesus monkeys and most human RBCs have antigenic Rh blood types, and this was used in naming the system. Rh represents the first 2 letters of the name Macacus Rhesus. Based on the presence or absence of the Rh factor, the blood group system is called the Rh blood group system. The ABO blood group system was named according to the different agglutinins, or blood group antigens, including A, B, and H (or O) antigens, on the surface of human RBCs. Karl Landsteiner first discovered the ABO blood group system in 1900 when he was investigating the causes of some fatal transfusions. The 2 main factors that determine the blood type are ABO (A, B, AB, and O) and rhesus (Rh) (positive or negative). A person’s blood type is determined according to the specific antigen types on the erythrocyte membranes of red blood cells (RBCs).

A negative blood type ethnicity