Pregnancy represents a unique immunological state where maternal immune adaptations play a pivotal role in
supporting fetal development while maintaining tolerance to the semi-allogeneic fetus. Blood transfusions, often
necessary during pregnancy for various medical conditions, present an intriguing avenue for understanding
alterations in maternal immunity. This comprehensive review aims to elucidate the intricate immunomodulatory
effects of blood transfusions on maternal immunity during pregnancy. Beginning with an exploration of normal
immunological changes in pregnancy, this review navigates through the immunomodulatory challenges posed by
blood transfusions. The impact of donor factors, transfusion-related immunological components, and their influence on the maternal immune system are scrutinized. Mechanistic insights into altered cytokine responses, adaptive
immune changes, and the role of regulatory T cells post-transfusion form critical focal points. Clinically, discerning
the implications of altered maternal immunity on fetal, neonatal health, and obstetric outcomes is essential.
Assessing risks and benefits associated with transfusions in pregnancy further underscores the clinical relevance of
understanding these immunomodulatory effects. Despite advancements, this review acknowledges research gaps
and limitations, highlighting the need for future investigations. Recommendations for prospective studies and
potential clinical implications conclude this review, emphasizing the significance of comprehending
immunomodulation in maternal immunity post-transfusion for optimizing maternal-fetal health. In conclusion, this
review encapsulates current knowledge, challenges, and future directions in comprehending the complex interplay
between blood transfusions and maternal immune responses during pregnancy, offering valuable insights into a
crucial aspect of perinatal medicine.
Keywords: blood transfusions; maternal immunity; pregnancy; immunomodulation; cytokines; alloimmunization;
inflammation; transplacental immunomodulation