Fetomaternal hemorrhage assessment in Rh-negative patients undergoing dilation and evacuation between 20 and 24 weeks' gestational age: A retrospective cohort study.

Objective: To estimate the rate of requiring more than one 300-mcg Rh D immune globulin dose for fetomaternal hemorrhage (FMH) at the time of second-trimester dilation and evacuation (D + E).

Study Design: We performed a retrospective cohort analysis of patients at greater than 20 weeks' gestation who underwent D + E, had Rh D-negative blood type, and received FMH quantification testing.

Results: Of 25 eligible patients, 24 had negative quantification of FMH; one had positive quantification that did not meet the clinical threshold for additional dosing.

Conclusions: The absolute risk of requiring additional Rh D immune globulin after D+E for pregnancies greater than 20 weeks' gestation was 0%.