Stillbirth in Shanghai, China: prevalence, fetal sex disparities, and gestational age trends over a decade

Objective To examine the prevalence, sex ratio, and gestational age distribution of stillborn disparities. Design This was a cross-sectional study. Setting A tertiary-care hospital in Shanghai, China. Population A population of 145200 pregnant women who delivered at the International Peace Maternity and Child Health Hospital between October 2014 and September 2024 was included. Methods After exclusion, 140594 pregnant women were included in the analyses. Stillbirth rates were calculated for the total population and for the sex ratio, and further analyses were conducted in gestational age subgroups (28-31 w, 32-36 w, and ≥37 w). We used the Mann‒Kendall trend test to identify the trend of stillbirth rates during the past years. Main outcome measures Risks of stillbirth in subgroups of each characteristic. Results The overall incidence of stillbirth in our hospital during the study period was 0.18% (249/140594). The observed upwards trend in the stillbirth rate from 2015 to 2023 was not statistically significant (Z=0.738; Z statistic; P value=0.461; Tau=0.229; Kendall's tau coefficient), with no statistically significant difference noted between stillbirth rates of 51.81% (129/249) for males and 48.19% (120/249) for females (χ² = 0.325; p= 0.5684). Regardless of sex, there were significantly more stillbirths at 28–31 weeks of gestation and significantly fewer stillbirths at greater than 37 weeks of gestation (χ²=28.79 (male) and 21.05 (female), p<0.001) (chi-square goodness-of-fit test). Conclusions Our study confirms a consistently low stillbirth rate in Shanghai over the past decade, with no significant temporal increase or sex-based disparities. Critically, stillbirth risk declines significantly with advancing gestational age in late pregnancy, highlighting the need for targeted monitoring and interventions for pregnancies at 28–31 weeks or earlier to further reduce the stillbirth burden.