A 6-hour-old boy is being evaluated in the nursery. He was born at 39 weeks gestation via spontaneous vaginal delivery to a 33-year-old primigravida. The pregnancy was complicated by intravenous drug use, and the mother was incarcerated for 2 months during the second trimester. First trimester serologies, including RPR, HIV antibodies, and hepatitis B surface antigen (HBsAg), were negative. Due to the mother's risk profile, follow-up testing was obtained during the third trimester and revealed the following: Liver function testing was normal. Hepatitis C and repeat HIV testing were negative. The remainder of the pregnancy was uncomplicated. The infant weighs 3.7 kg (8 lb 3 oz). Physical examination of the infant is normal. There is no jaundice or hepatomegaly. Which of the following is the most appropriate next step in management of this infant?

Question

A 6-hour-old boy is being evaluated in the nursery.  He was born at 39 weeks gestation via spontaneous vaginal delivery to a 33-year-old primigravida.  The pregnancy was complicated by intravenous drug use, and the mother was incarcerated for 2 months during the second trimester.  First trimester serologies, including RPR, HIV antibodies, and hepatitis B surface antigen (HBsAg), were negative.  Due to the mother's risk profile, follow-up testing was obtained during the third trimester and revealed the following:  Liver function testing was normal.  Hepatitis C and repeat HIV testing were negative.  The remainder of the pregnancy was uncomplicated.  The infant weighs 3.7 kg (8 lb 3 oz).  Physical examination of the infant is normal.  There is no jaundice or hepatomegaly.  Which of the following is the most appropriate next step in management of this infant?

Quizplus · Accepted Answer

11ec25c8_d6b7_f709_bc81_1fa7237bc23c_MD0003_00 Hepatitis B virus (HBV) can be transmitted vertically from infected pregnant women to their infants. This mother had negative HBsAg testing during the first trimester but became positive for both HBsAg and anti-hepatitis B core antigen (HbcAg) in the third trimester, suggesting she became infected with HBV during her pregnancy. The majority of vertical transmissions occur during the passage of the fetus through the birth canal; in rare cases, transplacental infection can occur, particularly in women with high HBV viral loads or acute infection in the third trimester. Approximately 90% of infants with vertical HBV infection progress to chronic HBV infection, which can lead to cirrhosis, hepatocellular carcinoma, and liver failure. Therefore, newborns of all mothers with active hepatitis B infection should be passively immunized at birth with hepatitis B immune globulin (HBIG), followed by active immunization with recombinant HBV vaccine. These should be administered within 12 hours of birth, regardless of the infant's birth weight or clinical condition. (Choices A and C) Active (HBV vaccine) or passive (HBIG) immunization alone does not provide suitable protection against vertical transmission. Vaccine and immune globulin should always be given together as prophylaxis against HBV for newborns of HBsAg+ mothers. (Choices D and E) Obtaining the infant's serologic status or liver function testing is unnecessary before administering prophylaxis. Infants should have their serologic status checked after the full HBV vaccine series is completed to determine whether they were vertically infected, and infants with confirmed infection should then have liver function tests. (Choice F) HBV infection is not transmitted through breast milk; HIV is the only absolute infectious contraindication to breastfeeding in the developed world. Because this mother is HIV-negative, breastfeeding should be encouraged. Educational objective: Newborns of mothers with hepatitis B virus (HBV) infection should receive passive immunization with hepatitis B immune globulin and active immunization with HBV vaccine within 12 hours of birth. References: Prophylaxis of vertical HBV infection. (http://www.ncbi.nlm.nih.gov/pubmed/27402246)

A 6-Hour-Old Boy Is Being Evaluated in the Nursery