Altered strategy of prophylactic anti-D administration in pregnancy to cover term and post-term - a pilot study.

Agneta Wikman, Anette Mörtberg, Elisabeth Jalkesten, Yvonne Jansson, Anita Karlsson, Eleonor Tiblad, Gunilla Ajne

Vox sanguinis 2021 Oct

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Routine antenatal anti-D prophylaxis (RAADP) to RhD-negative women is most often administered in gestational age (GA) 28-30 weeks with the next anti-D dose administered postpartum. The aim of this study was to analyse the proportion of RhD-negative women where RAADP is not detectable at term and in a pilot study to investigate whether RAADP administered in GA 28 and 38 results in detectable levels at term, post-term and post-delivery. In a retrospective analysis, 4280 RhD-negative women carrying an RHD positive fetus were included and the proportion with a negative antibody screen at delivery was determined. In the second part, 39 pregnancies were included prospectively, a second dose of RAADP was administered in GA 38 weeks, and anti-D was quantified before the second dose and then weekly for 5 weeks. In the retrospective analysis, 20·5% (856/4280) with RAADP administered in GA 28 were negative in routine antibody screening at delivery. In the small prospective study, 18% (7/39) had a negative antibody screen and 26% (10/39) had levels below 0·005 IU/ml, in the quantification assay, in GA 38. Anti-D prophylaxis administered in GA 38 showed detectable levels of anti-D up to 30 days post-delivery, with concentration at delivery 0·060 ± 0·034 IU/ml (mean ± SD). Approximately 20% of the RhD-negative women show non-detectable levels of anti-D at term. A second dose of RAADP at GA 38 results in stable concentrations of anti-D at term, post-term and post-delivery, but with large interindividual variation. © 2021 The Authors. Vox Sanguinis published by John Wiley & Sons Ltd on behalf of International Society of Blood Transfusion.

Citation

Agneta Wikman, Anette Mörtberg, Elisabeth Jalkesten, Yvonne Jansson, Anita Karlsson, Eleonor Tiblad, Gunilla Ajne. Altered strategy of prophylactic anti-D administration in pregnancy to cover term and post-term - a pilot study. Vox sanguinis. 2021 Oct;116(9):1005-1011