Prevalence and death rate of birth defects from population-based surveillance in Hunan Province, China, 2010-2020

To describe the prevalence and death rate of birth defects from population-based surveillance in Hunan Province, China. Data were obtained from the population-based Birth Defects Surveillance System in Hunan Province, China (2010-2020). The surveillance population included all live births, stillbirths, infant deaths, and legal terminations of pregnancy from 28 weeks of gestation to 42 days after birth between 2010 and 2020 when the mother resided in the surveillance area (Liuyang County and Shifeng District, Hunan Province). The prevalence of birth defects is the number of birth defects per 1000 infants (parts per thousand). The death rate of birth defects is the number of deaths attributable to birth defects per 100 birth defects (%). The prevalence and death rate with 95% confidence intervals (CI) were calculated by the log-binomial method. Crude odds ratios (ORs) were calculated to examine the association of each demographic characteristic with birth defects. Our study included 228,444 infants, and 4453 birth defects were identified, with a prevalence of 19.49 parts per thousand (95%CI 18.92-20.07). Congenital heart defects were the most common specific defects (5.29 parts per thousand), followed by limb defects (4.01 parts per thousand). Birth defects were more common in males than females (22.34 parts per thousand vs. 16.26 parts per thousand, OR = 1.38, 95%CI 1.30-1.47), in premature birth than not (91.82 parts per thousand vs. 16.14 parts per thousand, OR = 6.16, 95%CI 5.72-6.65), in birth weight < 2500 g (98.26 parts per thousand vs. 16.22 parts per thousand, OR = 6.61, 95%CI 6.11-7.15) or > 4000 g (19.48 parts per thousand vs. 16.22 parts per thousand, OR = 1.21, 95%CI 1.03-1.42) than birth weight 2500-4000 g, in hospitalized deliveries than other institutions (22.16 parts per thousand vs. 11.74 parts per thousand, OR = 1.91, 95%CI 1.76-2.07), in multiple births than singletons (28.50 parts per thousand vs. 19.28 parts per thousand, OR = 1.49, 95%CI 1.27-1.76), in maternal age < 20 years (26.33 parts per thousand vs. 18.69 parts per thousand, OR = 1.42, 95%CI 1.15-1.76) or > = 35 years (24.31 parts per thousand vs. 18.69 parts per thousand, OR = 1.31, 95%CI 1.18-1.45) than maternal age 25-29 years, and in number of pregnancies > = 4 (22.91 parts per thousand vs. 18.92 parts per thousand, OR = 1.22, 95%CI 1.10-1.35) than the first pregnancy. A total of 747 deaths attributable to birth defects were identified, including 603 (80.72%) stillbirths, 75 (10.04%) deaths within 7 days after birth, 46 (6.16%) deaths in 7-27 days after birth, 23 (3.08%) deaths in 28-42 days after birth. The death rate of birth defects was 16.78% (95%CI 15.57-17.98). Deaths attributable to birth defects accounted for 51.09% (747/1462) of all deaths. Central nervous system defects had the highest death rate (90.27%), and neonatal genetic metabolic defects had the lowest death rate (0.39%). In summary, we have described the prevalence and epidemiology of birth defects from population-based surveillance in Hunan Province, China, 2010-2020. There were differences in the prevalence and death rate of birth defects between population-based surveillance and hospital-based surveillance.