From the Guidelines
Rh-negative mothers with Rh-positive fetuses should receive Rho(D) immune globulin (RhoGAM) at 28 weeks of pregnancy and again within 72 hours after delivery if the baby is confirmed Rh-positive, as this has been shown to significantly reduce the risk of alloimmunization 1. The standard dose is 300 micrograms (μg) intramuscularly. Some key points to consider when administering RhoGAM include:
- Additional doses are needed after potentially sensitizing events such as miscarriage, abortion, ectopic pregnancy, amniocentesis, or trauma, ideally within 72 hours of the event.
- For first trimester events, a smaller dose of 50 μg is typically sufficient, while events after 12 weeks require the full 300 μg dose. This preventive treatment stops the mother's immune system from developing antibodies against the Rh factor in the baby's blood, which could cause hemolytic disease in future pregnancies, as supported by studies demonstrating a significant reduction in alloimmunization rates with the use of anti-D immunoglobulin 1. The introduction of a postpartum rhesus prevention program and antenatal prophylaxis has been shown to reduce fetal mortality from Rh hemolytic disease, highlighting the importance of this treatment in preventing long-term complications 1.
From the Research
Injection Times for Rh Positive Mothers
There is no specific information available regarding the injection times for Rh positive mothers, as the provided studies primarily focus on Rh negative mothers and the administration of Rho(D) immune globulin to prevent alloimmunization [ 2, 3, 4 ].
Rho(D) Immune Globulin Administration
- The administration of Rho(D) immune globulin is recommended for RhD-negative women to decrease the risk of alloimmunization [ 4 ].
- However, the provided studies do not specify the injection times for Rh positive mothers, as they are not typically administered Rho(D) immune globulin [ 2, 3, 4 ].
Prenatal Care for All Mothers
- Prenatal care should include routine fetal heart auscultation, urinalysis, and assessment of maternal weight, blood pressure, and fundal height [ 2 ].
- All pregnant women should be screened for asymptomatic bacteriuria, sexually transmitted infections, and immunity against rubella and varicella [ 4 ].
- Women should be offered prenatal serum marker screening for neural tube defects and aneuploidy [ 2 ].
Note: There are no research papers to assist in answering the question regarding the specific injection times for Rh positive mothers.