Citations 1
Clinical significance of anti‐M in pregnancy and self‐reported ancestry: The BEST collaborative study
Lu, Wen , Ziman, Alyssa , Yan, M. T. S., Virk, Mrigender , Stephens, Laura D. , Radwi, Ghazala, Morrison, Douglas, Marrero‐Rivera, Gisela , Ly, Judy , Ikeda, Kazuhiko, Hands, Katie , Malti, Salwa El, Eichbaum, Quentin , Covello, Thomas, Chang, Shelley, Brancamp, Rachel , Badawi, Maha, AlMozain, Nour, Shan, Hua , Collaborative, The Biomedical Excellence for Safer Transfusion, AlMozain, Nour , Yin, Charles , Yan, Matthew T S , Stephens, Laura , Marrero-Rivera, Gisela , Hasan, Rida A , Clarke, Gwen , Bakhtary, Sara , Badawi, Maha , Ziman, Alyssa , Lu, Wen , Almozain, Nour , Raval, Jay S. , Radwi, Ghazala , Ly, Jane, Juskewitch, Justin E. , Ikeda, Kazuhiko, Hasan, Rida A. , Duncan, Jennifer, Bakhtary, Sara , Au, Nicholas H. C.
Transfusion | April 6, 2026 | Volume: 66 | Issue: 6 | Pages: 1086-1098
Abstract Background Anti‐M antibodies were described as rarely eliciting hemolytic disease of the fetus and newborn (HDFN) in pregnancy. More recent literature, primarily from Asia, reports severe HDFN attributed to maternal anti‐M. The objective of this study is to determine if there is a difference in the frequency and/or severity of anti‐M HDFN among subjects who self‐report as Asian compared to non‐Asian. Methods Retrospective data were collected from 18 sites. Fetuses/neonates affected by HDFN were categorized as unaffected, mild, moderate, or severe based on clinical management and outcomes. Results Anti‐M was identified in 557 obstetric patients. Among 332 neonates with complete data for analysis, anti‐M was detected in isolation during the pregnancies of 210 (63.3%) neonates; 198 (94.3%) were unaffected by HDFN. The overall frequency of HDFN was 6.5% (2/31) in Asian patients and 5.6% (10/179) in non‐Asian patients. The frequency of severe HDFN was 6.5% (2/31) among Asian patients and 0.6% (1/179) among non‐Asian patients. Among non‐Asian patients, eight (4.5%) were mild and one (0.6%) was moderate. Of 63 pregnancies with anti‐M and ABO incompatibility, 6 (9.5%) were associated with mild HDFN and 57 (90.5%) were unaffected. Of 49 pregnancies with anti‐M and non‐ABO antibody(s), 6 (12.2%) were associated with mild HDFN and 43 (87.8%) were unaffected. One case (10.0%) of HDFN (mild) occurred in the presence of anti‐M, additional antibody(s), and ABO incompatibility. Conclusion In this study, severe anti‐M HDFN was rare in non‐Asian subjects. There is a signal that Asian patients are at greater risk for severe anti‐M HDFN.