Feasibility and Validity of Mobile Phone-Based Proxy Full Pregnancy History (mPFPH) for Estimating Perinatal...

Robust estimates of perinatal mortality are essential for improving perinatal survival in low- and middle-income countries. Mobile phone surveys may offer a scalable alternative to in-person surveys for such estimates. This study assessed the feasibility and validity of mobile phone-based Proxy Full Pregnancy History (mPFPH) interviews in rural Bangladesh, comparing proxy-reported and self-reported full pregnancy histories collected via mobile phones.

Between June and November 2022, women who had experienced at least one adverse pregnancy outcome (index women) and their nominated closest confidants participated in mobile phone interviews. Self-reports served as the reference standard. We examined selection biases associated with mobile phone access and evaluated concordance between self- and proxy-reports for perinatal outcomes.

A total of 1838 index women and 1328 confidants were enrolled. Non-response rates ranged from 2.1% to 26.5%, with non-respondents more likely to be younger, multiparous, and from smaller households. Average interview durations ranged from 7.5 to 25 min. Compared with self-reports, proxy reports by index women and closest confidants underreported neonatal deaths by 9.9% (95% CI: 7.0%-12.8%) and 23.1% (95%-CI: 15.0%-31.2%), perinatal deaths by 13.6% (95%-CI: 11.2%-16.0%) and 21.3% (95%-CI: 15.1%-27.6%), early neonatal deaths by 11.6% (95%-CI: 8.2%-14.9%) and 20.5% (95%-CI: 11.6%-29.5%), stillbirths by 14.6% (95%-CI: 11.2%-18.0%) and 22.4% (95%-CI: 13.5%-31.2%), and other pregnancy losses by 30.8% (95%-CI: 27.1%-34.4%) and 46.9% (95%-CI: 41.4%-52.5%). The proxy-to-self rate ratios for index women were 0.91 (95%-CI: 0.79-1.04) for neonatal mortality, 0.89 (95% CI: 0.80-0.98) for perinatal mortality, 0.89 (95%-CI: 0.76-1.04) for early neonatal mortality, 0.88 (95% CI: 0.76-1.01) for stillbirths, and 0.74 (95% CI: 0.65-0.83) for other pregnancy losses.

The mPFPH method demonstrated feasibility through high response and completion rates, efficient call durations, and strong two-way validation. However, proxy reports underestimated perinatal mortality relative to self-reports. Further validation across diverse settings is needed before large-scale implementation.