In patients with hemolytic disease of the fetus and newborn (HDFN), a possible association exists between elevated body mass index (BMI) and weight and the reduced efficacy of anti-D prophylaxis, according to findings from a systematic review and meta-analysis published recently in The International Journal of Transfusion Medicine.
Among individuals with HDFN, maternal antibodies, which often are generated by fetal antigens, destroy fetal and neonatal red blood cells. The severity of HDFN can be impacted by a variety of factors, including strength of the antibodies, gestational age and quantity of maternal antibody production.
Anti-D prophylactic treatment can be administered via intramuscular or intravenous injection to RhD-negative mothers. Although the use of routine antenatal anti-D prophylaxis has dramatically decreased the number of HDFN cases, the effect of a patient being overweight (ie, BMI of >25-30 kg/m2) or obese (ie, BMI of >30 kg/m2) on anti-D prophylaxis remains to be elucidated. The researchers of the study sought to understand the effect of BMI on the efficacy of anti-D prophylaxis among Rhesus (Rh)D-negative pregnant women.
Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) protocols were performed to assess the impaired effectiveness of RhD prophylaxis in RhD-negative mothers with high BMIs who were carrying an RhD-positive fetus. The literature search involved relevant publications between Jan. 1, 1966, and Aug. 1, 2023.
Read more about HDFN signs and symptoms
Of the 5444 total publications collected within the time frame, a total of 10 articles fulfilled eligibility requirements and were included in the systematic review. Of these 10 publications, only three covered an investigation of BMI/weight values among pregnant RhD-negative mothers who were carrying an RhD-positive fetus and specifically focused on their anti-D serum concentrations. Therefore, these three studies were incorporated into the meta-analysis.
Quality of the studies selected was evaluated with use of the Strengthening the Reporting Observation Studies in Epidemiology (STROBE) checklist.
Results of the meta-analysis showed a significant negative relationship between high BMI/weight and serial anti-D levels among RhD-negative pregnant women carrying RhD-positive fetuses. Moreover, elevated BMI/weight had a lower likelihood of a serial anti-D level being >30 ng/mL.
“[F]urther studies should explore the long-term clinical outcomes of altered anti-D prophylaxis dosing based on BMI/weight,” the authors emphasized. “Additionally, investigating the mechanism underlying the observed relationship between BMI/weight and anti-D levels would provide valuable insights,” they concluded.
