Stillbirth burden and associated factors in Chengdu, Western China: a population-based retrospective study, 2019-2024

Stillbirth remains a significant global public health concern, imposing considerable psychological, social, and economic impacts on families. However, limited research exists on its burden and determinants in Western China. This study aimed to evaluate the burden of stillbirth, defined as its incidence and recent trends, and to examine associated factors in Chengdu, a major city in the region.

A retrospective study was conducted using data from the Chengdu Maternal and Child Health Information System for deliveries between 2019 and 2024. The study included 946,299 Chinese women aged 15-49 years with gestational ages between 20 and 42 weeks. Multivariable modified Poisson regression models were used to estimate adjusted incidence risk ratios (aIRRs) and 95% confidence intervals (Cls).

Stillbirth rates in Chengdu increased overall between 2019 and 2024, ranging from 4.07 to 5.36 per 1,000 births. Risk factors significantly associated with stillbirth included maternal age ≥ 35 years (aIRR: 1.59, 95% CI: 1.36, 1.85), overweight (aIRR: 1.30, 95% CI: 1.09, 1.56) or obesity (aIRR: 1.52, 95% CI: 1.13, 2.04), uterine scarring (aIRR: 9.79, 95% CI: 7.79, 12.29), preeclampsia/eclampsia (aIRR: 4.65, 95% CI: 2.56, 8.45), placental abruption (aIRR: 26.15, 95% CI: 13.09, 52.24), small-for-gestational-age infants (aIRR: 4.83, 95% CI: 4.28, 5.45), multiple gestations (aIRR: 10.67, 95% CI: 8.18, 13.92), conception via assisted reproductive technology (aIRR: 1.79, 95% CI: 1.41, 2.28), and assisted vaginal delivery (aIRR: 2.13, 95% CI: 1.77, 2.56). In contrast, higher maternal education (aIRR: 0.79, 95% CI: 0.68, 0.92 for college/university; aIRR: 0.34, 95% CI: 0.22, 0.54 for postgraduate), multiparity (aIRR: 0.84, 95% CI: 0.74, 0.95), female fetal sex (aIRR: 0.88, 95% CI: 0.80, 0.97), and cesarean delivery (aIRR: 0.03, 95% CI: 0.03, 0.04) were associated with a lower risk. Stratified analyses showed higher early stillbirth risk among women with rural hukou status (aIRR: 1.76, 95% CI: 1.16, 2.69).

Although annual stillbirth rates in Chengdu remain below national and global averages, a recent increase in third-trimester losses highlights the need for strengthened maternal health surveillance. Targeted interventions addressing modifiable risk factors, improving prenatal monitoring, and narrowing urban-rural disparities hold promise for further reducing stillbirth rates.