Impact of a mother's ABO blood group on fetal growth and pregnancy-induced hypertension

Abstract

Background: Blood type, as defined by the ABO system, has been identified as a potential contributor to various medical conditions. However, its influence on pregnancy complications remains under-explored, particularly regarding fetal growth and hypertensive disorders of pregnancy. This research seeks to investigate whether an individual's ABO blood group plays a role in unfavorable pregnancy outcomes, with a specific focus on infants born smaller than expected and the development of preeclampsia.Methods: Medical records, encompassing ABO blood group classifications, were obtained from the hospital's records and subjected to a backward-looking examination. The study concentrated on two particular pregnancy-related complications: hypertensive disorder of pregnancy and neonates with suboptimal weight. The duration of gestation at the time of delivery was also documented for each study participant.Results: Analysis of 2552 maternal medical records from our institution revealed the following blood type distribution: O (27.7%, N=708), A (48.5%, N=1236), B (17.2%, N=440), and AB (6.6%, N=168). Notably, offspring of type B mothers exhibited significantly reduced birth weights compared to those of O, A, and AB mothers. Gestational length at delivery showed no statistically significant variation among blood groups. The study identified 200 cases of gestational hypertensive disorders. No correlation was found between ABO blood classification and the incidence of this pregnancy complication.Conclusions: While a link was observed between maternal blood group and reduced neonatal weight, no such relationship was evident between blood type and hypertensive disorders of pregnancy. We theorize that genetic factors in maternal and fetal immune systems, which are closely tied to ABO blood group determination, may influence gestational processes, leading to variations in fetal growth and subsequent birth weight.