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Prevention of Mother to Child Transmission (PMTCT) of HIV. HAIVN Harvard Medical School AIDS Initiative in Vietnam. Learning Objectives. By the end of this session, participants should be able to: Describe modes of mother to child transmission (MTCT) of HIV Explain the risk factors for MTCT
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Prevention of Mother to Child Transmission (PMTCT) of HIV HAIVN Harvard Medical School AIDS Initiative in Vietnam
Learning Objectives By the end of this session, participants should be able to: • Describe modes of mother to child transmission (MTCT) of HIV • Explain the risk factors for MTCT • Describe ways to prevent MTCT • Explain use of ARVs in pregnancy and for PMTCT
Overview: HIV in Women (1) • Globally, 15.9 million adult women living with HIV • 65% of PLHIV in sub-Saharan Africa are women • 43% of PLHIV in Caribbean are women • Proportion of women living with HIV in Latin America, Asia and Eastern Europe is increasing
Overview: HIV in Women (2) Percent of adults living with HIV who are female (1990-2007) WHO and CDC. Prevention of mother-to-child transmission of HIV Generic Training Package, Draft. January 2008.
Percentage of Pregnant Women Receiving an HIV Test, 2005, 2008, 2009 Towards universal access: Scaling up priority HIV/AIDS interventions in the health sector by WHO, UNICEF, UNAIDS, 2010 17%
Percentage of HIV + Pregnant Women Receiving ARVs for PMTCT 2005, 2008, 2009 Towards universal access: Scaling up priority HIV/AIDS interventions in the health sector by WHO, UNICEF, UNAIDS, 2010 32%
Mother to Child Transmission (MTCT) in Vietnam • National Sentinel Surveillance Data: • HIV prevalence in Vietnam 0.5% • HIV-1 prevalence in antenatal women 0.4% (0-1.9%) • 1.5-2 million births per year • 6000-7000 babies exposed to HIV at birth
Question: What are the three main times that a mother can transmit HIV to her infant?
MTCT Overview (1) MTCT can occur during: • Pregnancy (5-10%) • Labor and delivery (10-20%) • Breastfeeding (10-15%) Without intervention, the overall MTCT rate is 25-40%
10-20% 5-10% 10-15% Pregnancy Breast feeding Delivery MTCT Overview (2)
Pathogenesis: HIV Transmission During Pregnancy • HIV can cross from mother's blood through placenta's membrane to fetus • Thinning of membrane during later months of gestation facilitates HIV crossing over • CD4 cells containing HIV virus can also infiltrate through placenta to fetus
Pathogenesis: HIV TransmissionDuring Labor/Delivery • Factors facilitating transmission: • Uterine contractions and bleeding • Vaginal and cervical excoriations, ulcerative STDs bleeding • Fetal injury or excoriations bleeding due to episiotomy, forceps or vacuum • Baby swallows vaginal fluids containing HIV
Pathogenesis: HIV TransmissionDuring Breastfeeding • Transmission risk during breastfeeding depends on: • Use of safer breastfeeding practices • avoidance of mixed feeding • Duration of breastfeeding:
MTCT Risk Factors (1) Antepartum • Advanced maternal HIV disease • High viral load in mothers • MTCT < 1% if maternal viral load < 1000 • Viral load > 35,000 – higher in utero transmission • Viral load > 10,000 - higher intrapartum transmission
MTCT Risk Factors (2) Intrapartum • Prolonged rupture of membrane > 4 hours • Chorioamnionitis • Vaginal delivery compared to caesarean section when viral load > 1000 • Invasive procedures • scalp electrodes, etc
MTCT Risk Factors (3) Postpartum • Breastfeeding, risk is higher with: • Long duration • Mixed feeding in first 6 months • Breast infection • Infant with oral lesions • Pre-term, low birth weight infants
MTCT Risk Factors (4) • Other • STDs, especially ulcerative • Illicit drug use • Nutritional status
Small Group Activity: What are Some Ways to Prevent Mother to Child Transmission?
PMTCT Strategies Timely PMTCT interventions save babies
The Use of Caesarean Sections to Reduce MTCT • A scheduled C-section at 38 weeks decreases risk of transmission by approximately 50% • However, surgical risks may outweigh potential benefits in areas where this procedure is not performed often • Not recommended unless obstetrically indicated
What Are The Criteria For Starting Triple ART In A Pregnant Woman in Vietnam? The criteria to start a woman on ARV treatment are the same for pregnant and non-pregnant women
Criteria for ART Initiation in Pregnant Women • CD4 ≤ 350 cells/mm³ irrespective of clinical stage • Clinical stage 3 or 4 irrespective of CD4 cell count Modification and Supplement to the Guidelines for Diagnosis and Treatment of HIV/AIDS, MOH November 2011
ART Regimens Recommended in Pregnancy Guidelines for the Diagnosis and Treatment of HIV/AIDS. Ministry of Health, 2009. AZT + 3TC + NVP
Reminder: NVP Hypersensitivity • Most common side effects are rash and hepatic adverse events • Risk of symptomatic rash with hepatic toxicity is 9.8 times more common in women with CD4 > 250 • Unknown whether risk is increased in pregnant women, though cases have been reported
Viral Load and the Risk of MTCT • High maternal viral load is a major risk factor for MTCT of HIV • This supports the idea that the risk of transmission is most related to the baby’s overall exposure to virus • Therefore, reducing maternal viral load by ARVs is an effective way to prevent MTCT
PMTCT Regimen A: Infant • A single dose of NVP 6 mg, immediately after birth PLUS • AZT4mg/kg twice daily for 4 weeks
PMTCT Regimen B: Infant • AZT4mg/kg twice daily for 4 weeks
Triple ART in PMTCT Triple ARV treatment, if available, may be safely started any time after the first trimester Benefits: • Lowers VL most effectively in mother • Reduces transmission to < 2% • Decreases risk of viral resistance Downsides: • More expensive • Higher pill burden • More monitoring required
Single-Dose Nevirapineat Delivery Benefits • Inexpensive • Easy to implement • Effective for women who present late to care • Transmission rate reduced from 30% to 12% Downsides • Less effective than other regimens • Risk of NNRTI resistance
Scenario 1 Nga has been taking ARVs for the past 6 months, and recently found out that she is pregnant. What is the appropriate course of action in this scenario?
Scenario 1: Action First, review her ARV regimen, then use chart below to determine course:
Scenario 2 Trang is pregnant and HIV positive. She is eligible for ARVs, but has not yet started to take them. What is the appropriate course of action in this scenario?
Scenario 2: Action: Start ART • *Contraindications to NVP: CD4 > 250 cells/mm3, allergy to NVP, or history of NVP hepatotoxicity
Scenario 3 • Lan Anh is pregnant and HIV positive, but is not yet eligible for ARVs. What is the appropriate course of action in this scenario?
Scenario 3: Answer • Follow PMTCT protocol • Prescribe ARVs for PMTCT
Antenatal Care Assess HIV status Mother needs ART Mother does not need ART Intrapartum AZT + 3TC + single dose NVP Antepartum AZT from 14 weeks Post partum AZT + 3TC for 7 days For newborn AZT-3TC-NVP Single dose NVP immediately Followed by AZT 4 weeks ARVs in Pregnancy: Summary
Key Points • Increasing number of women in Vietnam with HIV; more babies potentially exposed • MTCT can occur during: • Pregnancy • Labor and delivery • Breastfeeding • PMTCT strategies include: • HIV counseling and testing • ART • Avoid breastfeeding
Thank you Questions?