What is the best recommendation for a 27-year-old primigravid (first pregnancy) woman at 16 weeks gestation, with a blood type of O, Rh negative, and no immunity to Rubella (German measles) and Varicella (chickenpox), presenting with mild anemia (hemoglobin 11.2 g/dL) and normocytic anemia (mean corpuscular volume 84 fL)?

From the Guidelines

The best recommendation for this patient is to administer Rh immune globulin (RhoGAM) at 28 weeks gestation and again within 72 hours after delivery if the infant is Rh positive, and to start oral, low-dose (30 mg/day) supplements of iron at the first prenatal visit, as well as receive the Tdap vaccine during the third trimester of pregnancy. This is necessary because the patient is Rh negative, which creates a risk for Rh sensitization if the fetus is Rh positive, and iron supplementation is recommended for all pregnant women to prevent iron deficiency anemia, as stated in the study by the Centers for Disease Control and Prevention 1. During pregnancy or delivery, fetal blood can enter the maternal circulation, potentially causing the mother to develop antibodies against Rh-positive blood. These antibodies can cross the placenta in subsequent pregnancies and attack the red blood cells of an Rh-positive fetus, leading to hemolytic disease of the newborn. RhoGAM prevents this sensitization by neutralizing any fetal Rh-positive cells that enter the maternal circulation before the mother's immune system can respond. The standard dose is 300 mcg intramuscularly. Additionally, the patient should receive the Tdap vaccine during the third trimester of pregnancy, as recommended by the Infectious Diseases Society of America 1, to provide passive immunity to the infant. The patient should also receive the MMR and varicella vaccines postpartum due to her lack of immunity, but these live vaccines are contraindicated during pregnancy.

Some key points to consider:

• The patient's hemoglobin level is 11.2 g/dL, which is within normal range for pregnancy, but iron supplementation is still recommended to prevent iron deficiency anemia.
• The patient's lack of immunity to rubella and varicella requires postpartum vaccination with live vaccines, which are contraindicated during pregnancy.
• The Tdap vaccine is recommended during the third trimester of pregnancy to provide passive immunity to the infant, as stated in the study by the Infectious Diseases Society of America 1.
• The patient's Rh negative status requires administration of Rh immune globulin (RhoGAM) at 28 weeks gestation and again within 72 hours after delivery if the infant is Rh positive.

From the FDA Drug Label

Although a lesser degree of protection is afforded if Rh antibody is administered beyond the 72-hour period, HyperRHO S/D Full Dose may still be given. For antenatal prophylaxis, one full dose syringe of HyperRHO S/D Full Dose (1500 IU; 300 mcg) is administered at approximately 28 weeks’ gestation. If abdominal trauma, amniocentesis, or other adverse event requires the administration of HyperRHO S/D Full Dose (1500 IU; 300 mcg) at 13 to 18 weeks’ gestation, another full dose should be given at 26 to 28 weeks

The patient is at 16 weeks gestation and has no history of Rh sensitization. Antenatal prophylaxis with Rh immune globulin is recommended at approximately 28 weeks’ gestation. Since the patient is currently at 16 weeks gestation, no action is required at this time. The patient should receive a full dose of HyperRHO S/D Full Dose (1500 IU; 300 mcg) at approximately 28 weeks’ gestation 2.

From the Research

Patient Recommendations

The patient is a 27-year-old primigravid woman at 16 weeks gestation with no medical issues or previous surgeries. She has no history of sexually transmitted infections and her family history is noncontributory. Her blood type is O, Rh negative, and rubella and varicella titers show no immunity.

Vaccination Recommendations

• The patient should be advised to receive the MMR (measles, mumps, and rubella) vaccine and varicella vaccine postpartum, as she is not immune to these diseases 3.
• Two doses of the MMR vaccine and varicella vaccine, separated by 4 weeks, are recommended for all adults who do not have immunization or contraindications 3.
• The patient's lack of immunity to varicella puts her at risk for severe varicella infection during pregnancy, and postpartum vaccination can help prevent this 4.

Considerations for Pregnancy

• The patient is currently pregnant and should not receive live vaccines, such as the MMR and varicella vaccines, during pregnancy 5, 6.
• The patient's healthcare provider should discuss the risks and benefits of vaccination with her and recommend postpartum vaccination to protect her against measles, mumps, rubella, and varicella.

Additional Recommendations

• The patient's healthcare provider should also discuss the importance of Rh immune globulin administration at 28 weeks gestation, as she is Rh negative [7 is not relevant to this point].
• The patient should be counseled on the importance of receiving all recommended vaccinations to protect herself and her newborn against vaccine-preventable diseases.