Prevalence and risk factors of stillbirths among pregnant women from twelve high-volume birthing facilities of Karachi, Pakistan: a longitudinal cohort study.

BACKGROUND: Stillbirth, defined as the death of a fetus at or after 22 weeks of gestation, remains a neglected public health issue, with approximately 2 million stillbirths occurring annually. Pakistan ranks among the top three countries with the highest number of stillbirths, yet progress in reducing stillbirth rates remains slower than regional and global averages. Despite the substantial burden, there is a lack of evidence on the prevalence, geographic variation, and predictors of stillbirths in Pakistan, particularly from marginalized settings. METHODS: We conducted a longitudinal cohort study in 12 selected public and private birthing facilities located in Karachi, Sindh, Pakistan between February 9, 2021, and January 1, 2022. We enrolled pregnant women visiting the selected birthing sites during antenatal care visits and those directly visiting for deliveries. We used the World Health Organization (WHO) standard definition of stillbirth occurring at a gestational age of ≥22 weeks. We analyzed stillbirth rates across birthing sites, geographic location, and gestational age, and used firth logistic regression to identify risk factors for stillbirths. RESULTS: Of the pregnant women enrolled (n = 21,523), 63.5% (13,668/21,523) with a gestational age ≥ 22 weeks delivered their babies at the study birthing facilities. The overall weighted stillbirth rate was 12.0 per 1,000 births across all sites. The prevalence varied substantially across sites, geographic location, gestational age, and facility type (public or private). Multivariable logistic regression showed a significant association between polio-endemic super high-risk union councils (AHR: 3.53; CI: 1.84-6.75), preterm delivery (AHR: 3.97; CI: 1.42-11.16), unvaccinated for Tetanus Toxoid (TT) vaccine during pregnancy (AHR: 5.29; CI: 2.61-10.74), and having received <8 ANC visits (AHR: 2.40; CI: 1.04-5.53) with stillbirth outcomes. CONCLUSION: Our study found significant variation in stillbirth prevalence across birthing facilities and geographic locations, with notably higher stillbirth rates in polio-endemic regions. These findings highlight the need for integrated approaches that combine polio eradication efforts with enhanced maternal healthcare services including maternal immunizations to maximize efficiency and impact. Additionally, efforts are needed to ensure high-quality antenatal care services and efficient management of medical conditions and prematurity during pregnancy.