Pregnancy outcome documentation in low-resource settings: a multi-country study

As the maternal vaccine portfolio expands, reliable documentation of adverse events of special interest (AESI) is critical for safety surveillance in low- and middle-income countries (LMIC). However, such documentation is often not easily available, even prior to introduction of new vaccines, and background rates are therefore lacking.

Nested within a retrospective multisite analysis of routine maternal health data from six LMICs (Bangladesh, The Gambia, Nepal, Nigeria, Tanzania, and Uganda) from 2019 to 2022, we extracted aggregated monthly counts of vaccination-relevant pregnancy AESI- preterm birth, stillbirth, congenital malformations, neonatal death, and maternal death- and assessed their availability, completeness, and consistency using descriptive analyses. Outcome rates were compared with published country-specific background estimates.

Among 123,867 pregnancies across 27 clinics (totaling 1277 clinic-months) in six LMICs, substantial limitations in pregnancy outcome recording were identified. AESI recording was predominantly paper-based (clinic registers in 92.6% of clinics, maternal-held documents in 51.9%); with use of digital systems in only 14.8% of clinics. Congenital malformations and preterm subcategories were absent in seven of 27 clinics (25.9%). Documentation completeness ranged from 65.2% to 68.9% for preterm birth categories to 96.8% to 98.4% for mortality outcomes (stillbirths, neonatal and maternal deaths). Considerable inter-clinic variability was noted, and observed rates diverged substantially from national background estimates for several pregnancy outcomes.

Substantial gaps in documentation of routine clinical data across LMIC underscore the need for linked, standardized, and digital maternal and neonatal outcome documentation to support the safe introduction and surveillance of vaccines administered during pregnancy.