The challenge of adherence during pregnancy and after
Polly Clayden, HIV i-Base
Data on adherence rates during and after pregnancy are limited. These data are important particularly as international guidance moves towards universal ART in pregnancy and during breastfeeding.
A systematic review and meta-analysis published in the 23 October 2012 edition of AIDS was conducted to estimate adherence rates in pregnancy and postpartum and found that achieving adequate adherence during this period was a challenge particularly after delivery. 
Jean Nachega and an international group of researchers performed a literature search, which included all studies from low-, middle-, and high-income countries reporting adherence rates in HIV positive women as a primary or secondary outcome. From the review, 72 articles were selected of which 51 met the inclusion criteria for the analysis.
The majority (74%) of the studies were observational and the remaining ones were RCTs evaluating PMTCT programmes. Most were conducted in the United States (27%), followed by Kenya (12%), South Africa (10%) and Zambia (10%). Almost half (45%) the studies reported adherence rates in women receiving ART, and 29% and 24% in women receiving AZT and single dose nevirapine (NVP) respectively. One study compared adherence rates between women receiving ART and those AZT. Adherence thresholds differed across studies from >80% to 100% and most used self reported questionnaires followed by pill count and pharmacy refills. Most studies (76%) reported adherence during the antepartum period, 8% post partum, and 16% reported rates during both periods.
A pooled analysis of all studies found an estimate of 73.5% (95% CI 69.3 – 77.5%) of women with adequate ART adherence (>80%). The pooled proportion of women who achieved adequate adherence was significantly higher during the antepartum (75.7%, 95% CI 71.5 – 79.7%) than the postpartum period (53%, 95% CI 32.8 – 72.7%, p=0.005).
The pooled adherence of women with good adherence rates was significantly higher in low- and middle-income countries (76.1%, 95% CI 72.2 – 79.7%) than in high-income countries (62%, 95% CI 50.1 – 73.3%, p=0.021). When the investigators excluded single dose NVP studies from the analysis, this difference became non-significant (74.3 vs 62%, p=0.062). When the analyses were limited to adherence thresholds of >90% (74.8 vs 69.7%, p=0.071) and 100% (78.3 vs 74%, p=0.103) the differences between low- and middle-income countries and high-income countries were also non-significant.
The investigators noted that this meta-analysis showed that adherence during pregnancy is significantly below that recommended for virologic suppression. They wrote: “It is crucial to monitor ART adherence, investigate specific barriers for nonadherence, and develop interventions to assist antepartum and postpartum women in adhering to ART and ensure the long-term efficacy of such an approach for both maternal health and PMTCT.”
The importance of adherence in pregnancy and post partum is a big consideration in discussions about WHO Option B+, ie all women starting lifelong treatment in pregnancy regardless of CD4.
There are many brilliant community models to support adherence. MSF recently launched a toolkit describing their very successful Adherence Clubs in the Western Cape. 
- Nachega J et al. Adherence to antiretroviral therapy during and after pregnancy in low-income, middle-income and high-income countries: a systematic review and meta-analysis. AIDS. Vol 26 No 16. 2012.
- MSF. ART Report and Toolkit.