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.