Table 1.

How Can Treatment Options Be Maintained in Children and Postpartum Women Receiving PMTCT Regimens: Summary of the WHO ResNet–CHAIN Group Discussions, October 2012

pMTCT considerations in mothers:
Women already on ART should continue their ART regimen and be managed as if they were nonpregnant. For women who are not on ART, Option B + bears, in principle, a lower risk of resistance than Options A or B. However, it is also affected by suboptimal ART adherence and drug stock-outs. Risk/benefit assessment of Options A, B, and B + :
	Option A	Benefits	Risks
		Overall, low risk of resistance, but such risk increases if the AZT/3TC tail is not properly followed Cheaper strategy with similar efficacy to Option B	More complex strategy than Options B or B + The strategy differs for women needing vs not needing lifelong ART based on CD4 counts, thus requires a fast turnaround of CD4+ tests to guide pMTCT choices; however, programs are moving to point-of-care CD4+ testing
	Option B	Benefits	Risks
		Maximum antiviral potency during pregnancy Suppression of HIV replication during pregnancy more likely than with Option A May have maternal health benefits over Option A Overall, easier to take and monitor during pregnancy than Option A Low risk of resistance on PI-containing regimens, but these are more expensive TDF/3TC/EFV as a once-daily single-tablet regimen is likely to be the best option; with such regimen, the tail may not be necessary thanks to the longer half-life of TDF and FTC (unknown)	Potential, but possibly small, risk of EFV-associated teratogenicity if EFV is used in first trimester Risk of selecting NNRTI resistance during NNRTI interruption, which might be more difficult to predict in African subjects due to PK variability: Requires a staggered stop of NNRTIs (eg, continuing TDF/3TC or AZT/3TC for 2 wk after TDF/3TC/EFV interruption, or switching to a PI-based regimen for 2 wk before interruption); this adds considerable complexity Relative to Option B + , women might be more likely to drop out of HIV care after delivery
	Option B +	Benefits	Risks
		Same benefits as Option B, plus: Does not require ART interruption, thereby avoids selection of NNRTI resistance at the end of pregnancy May have maternal health benefits over Options A or B May allow simplified infant prophylaxis, particularly during breastfeeding	Potential, but possibly small, risk of EFV-associated teratogenicity if EFV is used (particularly in women becoming pregnant again while taking EFV) Equally vulnerable to suboptimal adherence, and drug stock-outs as Options A and B Increased net cost, although possibly highly cost-effective
Infant prophylaxis:
The overriding aim of infant prophylaxis is to reduce vertical HIV transmission; regimens should be designed with this objective rather than for limiting antiretroviral drug resistance. Strategies should be designed to allow safe breastfeeding. It is unknown if NVP or ZDV for 6 wk is necessary in Options B or B+ or in women already on lifelong ART, as it increases complexity and may compromise scale-up of pMTCT. Conversely, providing infant prophylaxis may be particularly important in women who initiate ART late in pregnancy until the mother achieved full HIV suppression. Single-dose TDF or coformulated TDF/FTC could be a possible alternative to sdNVP in infants because it is less prone to develop high-level resistance after a single-dose administration; however, data are lacking and availability is still limited in many low-income countries.

Abbreviations: 3TC, lamivudine; ART, antiretroviral therapy; AZT, zidovudine; EFV, efavirenz ; FTC, emtricitabine; HIV, human immunodeficiency virus; NNRTI, nonnucleoside reverse transcriptase inhibitor; PI, protease inhibitor ; PK, pharmacokinetic; pMTCT, prevent mother-to-child transmission; sdNVP, single-dose nevirapine; TDF, tenofovir.