II. Epidemiology

  1. Women with AIDS are young: >80% are between ages 18-44
  2. HIV Prevalence in U.S. obstetrics patients: 1-5%
  3. Risks of vertical transmission
    1. HIV Viral Load <1000 copies per ml: 2% transmission
    2. HIV Viral Load >1000 copies/ml
      1. Untreated woman with HIV: 25% transmission
      2. AZT used intrapartum: 5-8% transmission
      3. AZT and Ceserean delivery: 2% transmission
  4. Racial discrepancy in Perinatally acquired HIV in United States (2009, CDC)
    1. Black patients: 9.9 in 100,000 live births
    2. Hispanic patients: 1.7 in 100,000 live births
    3. White patients: 0.1 in 100,000 live births
    4. http://www.cdc.gov/hiv/risk/gender/pregnantwomen/index.html

III. Risk Factors: Perinatal HIV Transmission Factors

  1. Risks of transmissions (13-39% with Zidovudine)
    1. Higher levels of maternal viremia (>1000 copies/ml)
    2. HIV core antigenemia
    3. Lower maternal CD4 Count
    4. Advanced clinical HIV disease
    5. Maternal immune factors and Viral factors
    6. Primary HIV Infection during pregnancy
    7. Chorioamnionitis
    8. Other Sexually Transmitted Disease
    9. Unprotected intercourse during pregnancy
    10. "Hard drug" use during pregnancy
    11. Invasive monitoring (e.g. fetal scalp electrodes)
    12. Premature birth or low birthweight infant
    13. Rupture of Membranes
      1. Artificial Rupture of Membranes
      2. Delivery more than 4 hours after ruptured membranes
    14. Instrumental deliveries (i.e. forceps or vacuum)
    15. DeLee Suction
    16. Vaginal Delivery
    17. Advanced maternal age
    18. First born of twins born to an HIV infected mother
  2. Factors that decrease risk of transmission
    1. Higher levels of neutralizing HIV Antibody titers
      1. Antibodies to certain epitopes of GP 120
    2. Elective Cesarean Section
    3. Zidovudine (AZT)
    4. Less invasive monitoring and intrapartum procedures

IV. Mechanisms: Vertical Transmission (Maternal to Child)

  1. Responsible for 90% of Pediatric HIV cases
  2. In Utero transmission (30%)
    1. Detected by PCR or Blood Culture
      1. Cord blood can not be used
      2. Results obtained in <48 hours
    2. Intrauterine HIV Transmission occurs early pregnancy
      1. Study of 124 HIV+ obstetric patients over 4 years
      2. Spontaneous Abortions 14 (11%) between 8-32 weeks
        1. HIV Positive on autopsy: 7 of 14 fetuses (50%)
      3. Reference
        1. Langston (1995) J Infect Dis 172:1451-60 [PubMed]
    3. Worse outcome then intrapartum transmission
      1. Associated with rapid HIV progression
      2. Newborn predictors of rapid course
        1. Hepatosplenomegaly
        2. Lymphadenopathy
        3. CD4+ Lymphocytes <30%
        4. HIV PCR positive within first week of life
        5. Mayaux (1996) JAMA 275:606-10 [PubMed]
  3. Intrapartum Transmission (70%)
    1. Mechanism
      1. Direct contact with maternal genital secretions
      2. Maternal-fetal micro transfusions
        1. Occur during labor as in Hepatitis B
      3. Possible ascending infections
        1. Similar Mechanism as Group B Streptococcus
        2. Increased transmission if Membranes Ruptured > 4h
    2. Infants subsequent Cultures
      1. Negative Culture or PCR within first 48 hours
      2. Positive Culture within 7-90 days after birth
    3. Higher risk for first twin delivered
  4. Postpartum transmission
    1. Breast Feeding is contraindicated in Maternal HIV

V. Labs

  1. Prenatal HIV Testing should be encouraged for all women
  2. See Pediatric HIV (for testing in the infant)
  3. Viral load and CD4 Count baseline and in each trimester
  4. PPD in second trimester

VI. Management: General Measures

  1. Treat all Sexually Transmitted Diseases
  2. Prevent opportunistic infections
  3. Diagnose Maternal HIV early
  4. Delivery within 4 hours of Rupture of Membranes
  5. Delivery by elective Cesarean Section at 38 weeks
    1. NSVD may be option if viral load <1000 copies/ml
    2. Ceserean does not reduce transmission if
      1. Labor starts prior to ceserean
      2. Spontaneous Rupture of Membranes
    3. Use best clinical evidence to estimate gestation
      1. Avoid Amniocentesis
    4. Use prophylactic antibiotics during Ceserean
      1. Most indicated in lower CD4 Counts
  6. Lactation is contraindicated (risk of HIV Transmission)
  7. Update vaccinations as needed
    1. Influenza Vaccine
    2. Pneumococcal Vaccine

VII. Management: Anti-Retroviral Therapy

  1. Treat HIV-infected pregnant women and infants!
    1. Mother on Antiretroviral drugs after 14 weeks
      1. NIH recommends same treatment as non-pregnant
      2. Consider multiple Retroviral drugs
      3. Includes the use of Protease Inhibitors
      4. (1999) MMWR Morb Mortal Wkly Rep 47(RR-5):1-41 [PubMed]
    2. Intravenous Zidovudine during labor
    3. Infants treated in first 6 weeks of life
  2. Decreases likelihood of maternal-infant transmission
    1. Zidovudine reduces overall transmission 25% to 8%
    2. Peripartum AZT reduces transmission by 30%
  3. Zidovudine (AZT) Protocol for HIV positive Mothers
    1. Nevirapine appears more effective than AZT
      1. Nevirapine protocols are being developed
      2. Guay (1999) Lancet 354:795-802 [PubMed]
    2. Antepartum (start at 14 weeks of gestation)
      1. Consider multi-Antiretroviral drug therapy
      2. Zidovudine (AZT) 100 mg PO 5 times per day
    3. Intrapartum
      1. Load: AZT 2 mg/kg over 1 hour
      2. Maintenance: AZT 1 mg/kg/hour until delivery
    4. Newborn
      1. See Pediatric HIV

VIII. Resources

  1. See HIV Resources
  2. Antiretroviral Pregnancy Registry
    1. Phone: 800-258-4263

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