HIV, Hepatitis Flashcards
How is HIV transmitted, when does transmission occur in pregnancy
HIV is an RNA retrovirus transmitted through sexual contact, blood and blood products, shared needles for IVDU or vertical transmission. Vertical transmission mainly occurs in the late third trimester during labour, delivery or breast feeding. Risk of vertical transmission is dependent on maternal plasma viral load, obstetric factors and infant feeding.
What is the prevalence of HIV in pregnancy
2.2 per 1000 pregnancies. Around 20,000 women in the UK live with diagnosed HIV, whilst an estimated 1300 have undiagnosed infection
What is the risk of verticla transmission of HIV if left untreated
Between 15-20% in non-breastfeeding women in Europe (25-40% in breastfeeding African populations)
What is the risk of vertical transmission of HIV which is being actively managed
- Transmission rates of less than 2% have been reported due to efficacy of HAART, appropriate management of delivery and avoidance of breastfeeding
Risk factors for vertical transmission
Advanced maternal HIV disease, high maternal plasma viral load, low CD4 lymphocytes counts, PROM, chorioamnionitis, preterm delivery, co-existing viral infection (HSV, Hep C), breastfeeding (doubles rates of transmission)
Protective factors against vertical transmission
Low or undetectable viral counts at the time of delivery, antiretroviral therapy delivery via C-section, exclusive formula feeding
What screening exists for HIV in pregnancy
- All pregnant women are recommended to have screening for HIV infection in every pregnancy at their booking visit- significantly improves care with early identification
- If a woman declines screening, her reasons should be explored sensitively to ensure that she has received accurate information. Should also involve a senior- decision to decline should be clearly documented and screening should be offered again around 28 weeks
- Fourth-generation laboratory assays are recommended as a 1st line test
- Rapid HIV tests are recommended for women with unknown HIV status who present in labour
What additional investigations for HIV are required in the antenatal period
- HIV resistance testing should be completed and results available prior to initiation of treatment, except for late-presenting women (after 28 weeks)- in this case, cART (combined anti-retroviral therapy) should be initiated without delay
- A minimum of one CD4 count should be taken on initiation of cART and one at delivery
- In women who commence cART in pregnancy, an HIV viral load should be performed 2-4 weeks after commencing cART, at least once every trimester, at 36 weeks and at delivery
- Hepatotoxicity may occur as a result of cART- therefore LFTs should be performed to monitor function
- Additional recommended blood tests for women who are HIV positive include hepatitis C, VZV, measles, toxoplasma
- Women who are HIV positive taking HAART at the time of booking should be screened for gestational diabetes
- Assessment of antenatal and postnatal depression should be undertaken at booking, 4-6 weeks postpartum and 3-4 months postpartum
- Prevalence of depressive symptoms amongst women living with HIV is nearly 30%
- All women should also be routinely asked about their social situation so that they can be referred to appropriate support if needed
- Foetal USS should be performed as for women without HIV, including an anomaly scan between 18 and 20+6 weeks
- Invasive prenatal diagnostic testing should not be performed until after the HIV status of the woman is known, and should ideally be deferred until HIV viral load has been adequately suppressed
How should HIV be managed in the antenatal period
- Antenatal HIV care should be delivered by an MDT: HIV specialist, obstetrician, specialist midwife and paediatrician. May also involve GP, social worker, psychiatrists etc.
- Arrange contact with joint HIV physician and obstetric clinic every 1-2 weeks
- A plan for contraception to be used postnatally should be discussed antenatally with each woman. Antiretrovirals may need to be changed postnatally to align with a woman’s choice of contraception
All women not on cART should commence cART (NOT harmful to baby):
* As soon as they are able to do so in the second trimester where the baseline viral load ≤30,000 HIV RNA copies/mL
* At the start of the second trimester, or as soon as possible thereafter, in women with a baseline viral load of 30,000–100,000 HIV RNA copies/mL
* Within the first trimester if viral load >100,000 HIV RNA copies/mL and/or CD4 cell count is less than 200 cells/mm3 .
* All women should have commenced cART by week 24 of pregnancy.
* Women on ART regimes that do not contain dolutegravir who are trying to conceive or in the first trimester of pregnancy (<12 weeks gestation) should take standard dose folic acid 400ug OD (should take 5mg otherwise)-> Higher prevalence of neural tube defects with dolutegravir
What cART regimen should be used in pregnancy
- Women not already on cART should start tenofovir or abacavir with emitricitabine or lamivudine as a nucleotide backbone. The third agent should be efavirenz or atazanavir (safest in pregnancy)
How should women be managed if they have been initiated on cART but have a viral load > 50 HIV RNA copies/ml
o Review adherence and concomitant medication
o Perform resistance test if appropriate
o Consider therapeutic drug monitoring
o Optimise best regimen and consider intensification
How should women be managed if they have been initiated on cART but have a viral load > 50 HIV RNA copies/ml
o Review adherence and concomitant medication
o Perform resistance test if appropriate
o Consider therapeutic drug monitoring
o Optimise best regimen and consider intensification
How is mode of delivery affected by HIV
For women with a plasma viral load of < 50 HIV RNA copies/ml at 36 weeks, and in the absence of obstetric complications, planned vaginal delivery should be supported.
* Once SVD is planned, management is no different to normal population
* VBAC can be offered with viral load < 50
For women with a plasma load of 50-399 at 36 weeks, prelabour c-section should be considered (taking into account trajectory of the viral load, adheranc issues, length of time on treatment)
Where the viral load is >400, PLCS is recommended
* Where prevention of vertical transmission is the indication for CS, it should be undertaken between 38 and 39 weeks
Intrapartum IV zidovudine infusion is recommended:
* For women with a viral load >1000 who present in labour or with SROM or who are admitted for PLCS
* For untreated women who present in labour or with SROM in whom viral load is not known
How is PROM and PPROM managed in women with HIV
- In prelabour SROM, delivery within 24 hours should be the aim (can do IOL if load is < 50)
- The management of PPROM at >34 weeks is the same as that of SROM, except that women at 34-37 weeks gestation will require GBS prophylaxis (since preterm)
- When PPROM occurs at < 34 weeks:
o Intramuscular steroids should be administered in accordance with guidelines
o Where HIV viral load is not controlled, this should be optimised
o There should be an MDT decision about timing and mode of delivery
IS risk increased in women with HIV and multiple pregnancy
No
