1. Presented by Sanika Satoskar, MD and reviewed by Herleen Rai, MD

An adult female presented to Labor & Delivery late in her pregnancy for obstetric management of preeclampsia. The patient’s history is significant for daily IV drug use. She has received no prior prenatal care during this pregnancy. Ultrasound imaging reveals the fetus to be in the cephalic position with a size that is appropriate for gestational age. A type and screen was performed.

 

 

Subsequently, the patient undergoes labor induction and delivers a newborn female weighing 6 lbs. 5 oz. A cord blood sample is collected and ABO/Rh type performed with the following results:

 

 

As part of the workup, a maternal sample is sent down for a fetal-maternal hemorrhage (FMH) screen and yields a positive result. The follow-up Kleihauer-Betke test reveals 4.1% fetal cells in maternal circulation. What is the appropriate dose of Rh immunoglobulin (RhIg) dose (if any) that the mother should receive?