From prophylaxis to parturition: evaluating antibody screen reactivity following antenatal anti-D at 28 weeks

A single 300-µg anti-D dose at 28 weeks leaves nearly two-thirds of RhD-negative women serologically undetectable for anti-D at term once the prophylaxis-to-delivery interval exceeds 10 weeks. While this suggests a potential late-gestation coverage gap, it does not directly establish the level of immunologic protection or the risk of new alloimmunization. Therefore, strategies such as a second antenatal dose at 34-36 weeks, late-pregnancy IAT-triggered boosters, or BMI-adjusted dosing should be prospectively evaluated within the framework of existing national guidelines to further minimize residual RhD alloimmunization.