Association Between Maternal Blood Group and Anaemia in First-trimester Pregnancy: A Cross-sectional Study from Tamil Nadu, India
TL;DR
Blood group typing may serve as a supplementary biological marker for identifying vulnerable populations, but effective prevention and management should prioritise evidence based strategies with routine iron supplementation, early haematologic screening, and structured nutritional education to reduce the burden of anaemia, particularly in pregnancy.
Abstract
Introduction: Iron Deficiency Anaemia (IDA) is a significant public health concern among first-trimester pregnant women in India, particularly in Tamil Nadu. Given the dual burden of maternal anaemia and the potential role of blood group as a biological determinant, exploring this relationship is essential. Elucidating such relationships may strengthen antenatal care by enabling risk based screening, improved antenatal care practices, personalised interventions, and ultimately better maternal and neonatal outcomes. Aim: To assess the association between maternal blood group and iron deficiency anaemia among pregnant women in their first trimester attending a hospital in Tamil Nadu, India. Materials and Methods: This hospital-based, cross-sectional study was conducted at the Department of Obstetrics and Gynaecology of SRM Medical College and Hospital, Faculty of Medicine and Health Sciences, S.R.M. Institute of Science and Technology, Kattankulathur, Chengalpattu, Chennai, Tamil Nadu, India, for six months, from July 2025 to December 2025, among 280 pregnant women in their first trimester. Initial obstetric evaluation included basic analytes such as iron, Transferrin Iron Binding Capacity (TIBC), % Transferrin Saturation (TSAT), haemoglobin and blood group. Iron profile was evaluated in a Beckman Coulter DXC700 analyser. Subjects were categorised as Group A with mild anaemia, Group B with moderate anaemia and Group C with severe anaemia. Normality of the variables was evaluated by applying the Shapiro-Wilk test, and it was demonstrated as skewness, non parametric methods were employed. Descriptive statistics were expressed as median values with interquartile ranges, while categorical variables were summarised as frequencies and percentages. Results: A total of 280 women in the first trimester of pregnancy were enrolled in this study. The mean age of the participants was 26.86±4.52 years. The distribution of ABO blood groups among participants was as follows- group O- 120 (43%), Group A- 53 (18.92%), group B- 92 (33%), group AB- 15 (5.36%). This distribution highlights the predominance of group O, followed by group B, consistent with population level data. Out of 280 participants, the majority of participants were Rh positive 246 (87.86%), while a smaller proportion were Rh negative 34 (12.14%). The AB+ group had the lowest median haemoglobin concentration among the blood groups studied; however, between-group statistical comparisons were not performed/ reported. Participants with Hb less than 11 g/dL were 131 (46.78%), and haemoglobin levels more than 11 g/dL were 149 (53.22%). About 3 (2.29%) had severe anaemia with Hb less than 8 g/dL, 58 (44.27%) had moderate anaemia with Hb levels ranging between 8 and 9.9 g/dL and 70 (53.44%) had mild anaemia with Hb levels between 10 and 10.9 g/dL. Conclusion: Blood group typing may serve as a supplementary biological marker for identifying vulnerable populations, but effective prevention and management should prioritise evidence based strategies with routine iron supplementation, early haematologic screening, and structured nutritional education to reduce the burden of anaemia, particularly in pregnancy.
