Background: There is global consensus that there is benefit to providing Rh immune globulin in the third trimester to prevent immune sensitization and consequent pregnancy complications, however, evidence to guide management of Rh-negative women in the first trimester bleeding is lacking. Our preliminary data indicate that women undergoing abortion in the first trimester are exposed to very low levels of fetal-maternal hemorrhage, below the threshold of clinical significance. We therefore hypothesize that medication abortion patients have little to no risk of mounting a response to fetal red blood cells due to low exposure.
Methods: To test this hypothesis, and address patient-level disparities as well as enumerate the societal costs associated with Rh immune globulin administration in the first trimester, we propose a prospective cohort study.
Proposed analysis: Data collected will be used to 1) determine the concentration of fetal red blood cells in patients’ circulation following medication abortion using our highly sensitive flow cytometry protocol; 2) ascertain facilitators and barriers to accessing Rh immune globulin in the first trimester, and 3) determine the patient, healthcare sector and societal costs associated with the practice of giving Rh immune globulin to medication abortion patients.