Recommendations for antenatal calcium supplementation to prevent preeclampsia could substantially reduce maternal mortality, but adherence to multiple daily doses may constrain effectiveness. World Health Organization guidelines recommend 3 daily calcium supplements (1.5-2 g/d), taken separately from 1 iron-folic acid (IFA) supplement; however, limited data suggest lower calcium doses may also be effective. We conducted mixed-methods household trials to identify strategies for supporting adherence and integrating calcium into antenatal IFA supplementation programming in Ethiopia. Participants were randomly assigned to 3 regimens varying in dose and timing and were later given a choice of regimens. Semistructured interviews conducted over 6 weeks explored acceptability, barriers, and facilitators and offered opportunities to choose calcium pill type. Interviews were transcribed, translated, and analyzed thematically. Calcium adherence was measured using medication event monitoring. All participants (N=48) agreed to try supplementation. Adherence barriers included forgetting to take pills when busy or travelling and perceived side effects. Midday doses were the most challenging because of farming, market, and social events; women avoided taking supplements in public due to fear of being perceived as HIV positive. Social support from families, visual reminders, and anticipated benefits motivated adherence. More participants (75%) selected chewable versus conventional supplements due to organoleptic properties, but this preference declined over time. Adherence rates did not substantially differ across regimens with 2 (81.1%), 3 (83.4%), or 4 (77.1%) pill-taking events. Women indicated that the 2-event regimen was more acceptable than 3- and 4-event regimens, but this acceptability was not associated with higher adherence. Consequently, mean daily calcium consumption (811.3 mg) was lower than for 3-event (1,251.1 mg) and 4-event (1,156.4 mg) regimens. Integrating calcium into antenatal IFA supplementation is acceptable to Ethiopian women, with a 3-event regimen yielding the highest consumption rates. Despite women experiencing challenges with midday dosing and stigma, using simple home-based strategies and being counseled on the purpose of supplementation were more effective than reducing dosage for mitigating barriers and improving adherence.
© Klemm et al.