Rhesus testing and anti‐D prophylaxis in RhD‐negative women undergoing first‐trimester abortion—Systematic Review and Opinion

Background The introduction of immunoglobulin G (IgG) anti‐D prophylaxis for Rhesus D (RhD)‐negative women has substantially reduced the incidence of RhD alloimmunization and hemolytic disease of the fetus and newborn in Europe by 85%, transforming fetal health outcomes. However, there is little evidence for the need of giving IgG anti‐D prophylaxis to RhD‐negative women in first‐trimester abortions. Objectives To analyze the international and national evidence‐based guidelines on Rh testing and anti‐D prophylaxis in first‐trimester abortion, along with current literature both supporting and opposing this practice, to facilitate informed decision making in clinical practice. Search Strategy A systematic search was conducted in Pubmed/MEDLINE, EMBASE, Cochrane Library, Google Scholar, and Gry literature for publications from January 1, 2003 to January 17, 2024. Selection Criteria Guidelines, reviews, meta‐analyses, observational and qualitative studies, randomized trials, real‐world data, and cohort studies that addressed the use of IgG anti‐D prophylaxis in first‐trimester abortions were included. Data Collection and Analysis Identified studies were screened and assessed independently by two authors. A standardized extraction grid was used to extract information from the selected articles. Main Results Guidelines published from 2022 onwards, such as those from the World Health Organization, recommend against anti‐D for women undergoing first‐trimester abortion. In contrast, most older guidelines recommend RhD testing and the administration of IgG anti‐D prophylaxis in abortions even before 12 weeks of amenorrhea, although exact gestational age thresholds vary widely. These discrepancies in the management of RhD‐negative women undergoing first‐trimester abortion are caused by different interpretations of the available evidence, IgG anti‐D availability, cultural and social influences, as well as legal and regulatory considerations. Conclusions This review highlights the need for evidence‐based, harmonized guidelines on IgG anti‐D prophylaxis in first‐trimester abortions. It is crucial for healthcare providers to stay informed on the latest recommendations and engage in shared decision‐making with women undergoing first‐trimester abortion.