Clinically Significant Fetomaternal Hemorrhage: Incidence and Recurrence Rate [26I]

• Published in: Obstetrics and gynecology (New York. 1953) Vol. 133 Suppl 1; no. 1; p. 102S
• Main Authors: Boller, Marie J, Hung, Yun-Yi, Varghese, Reshma, Weintraub, Miranda Ritterman, Moore, Gaea S, Schauer, Galen M
• Format: Journal Article
• Language: English
• Published: by The American College of Obstetricians and Gynecologists. Published by Wolters Kluwer Health, Inc. All rights reserved 01.05.2019
• ISSN: 0029-7844; 1873-233X
• DOI: 10.1097/01.AOG.0000558803.79128.07

INTRODUCTION:Clinically significant fetomaternal hemorrhage (CS-FMH) occurs in 1/1000-1/5000 pregnancies and has an unknown risk of recurrence. We sought to establish recurrence rate by analyzing reproductive histories of patients with CS-FMH confirmed by flow cytometry in a large integrated health care system over a 10-year period (375,864 total births). METHODS:We conducted an IRB-approved retrospective case series of patients with a positive flow result (>0.1% fetal red cells in maternal circulation) from January 2008 through May 2018 within Kaiser Permanente Northern California (KPNC). For cases of CS-FMH we collected indication for testing, adverse outcomes, reproductive history and demographics. RESULTS:Of over 19,000 patients tested, 1105 had a positive flow result. Of these, 7.4% had a result > 1.0%, with 85.4% of these identified as CS-FMH. Of CS-FMH cases, 28.6% had a fetal demise, 71.4% had a symptomatic neonate, and 4.3% had a neonatal demise. 58.6% presented with decreased fetal movement. Excluding cases of fetal demise, 90.0% had an abnormal fetal heart rate tracing (14.0% sinusoidal). Autopsy supported CS-FMH in all but one case of demise. There were no predictive demographic characteristics for CS-FMH. There were no cases of recurrent CS-FMH. Collectively, affected patients had 126 additional pregnancies with 75 liveborns. At term, a flow result ≥4.0% had a positive predictive value (PPV) of 100% for CS-FMH. For preterm deliveries, a result ≥ 1.0% had a PPV of 100%. CONCLUSION:The incidence of CS-FMH in our diverse KPNC population is 0.19/1000. We did not find an increased risk of recurrence in future pregnancies.