Abstract
To describe the fetal death rate of birth defects (including a broad range of specific defects) and to explore the relationship between fetal deaths from birth defects and a broad range of demographic characteristics. Data was derived from the birth defects surveillance system in Hunan Province, China, 2016-2020. Fetal death refers to the intrauterine death of a fetus at any time during the pregnancy, including medical termination of pregnancy. Fetal death rate is the number of fetal deaths per 100 births (including live births and fetal deaths) in a specified group (unit: %). The fetal death rate of birth defects with 95% confidence intervals (CI) was calculated by the log-binomial method. Crude odds ratios (ORs) were calculated to examine the relationship between each demographic characteristic and fetal deaths from birth defects. This study included 847,755 births, and 23,420 birth defects were identified. A total of 11,955 fetal deaths from birth defects were identified, with a fetal death rate of 51.05% (95% CI 50.13-51.96). 15.78% (1887 cases) of fetal deaths from birth defects were at a gestational age of < 20 weeks, 59.05% (7059 cases) were at a gestational age of 20-27 weeks, and 25.17% (3009 cases) were at a gestational age of ≥ 28 weeks. Fetal death rate of birth defects was higher in females than in males (OR = 1.25, 95% CI 1.18-1.32), in rural than in urban areas (OR = 1.43, 95% CI 1.36-1.50), in maternal age 20-24 years (OR = 1.35, 95% CI 1.25-1.47), and ≥ 35 years (OR = 1.19, 95% CI 1.11-1.29) compared to maternal age of 25-29 years, in diagnosed by chromosomal analysis than ultrasound (OR = 6.24, 95% CI 5.15-7.55), and lower in multiple births than in singletons (OR = 0.41, 95% CI 0.36-0.47). The fetal death rate of birth defects increased with the number of previous pregnancies (χ(2)(trend) = 49.28, P < 0.01), and decreased with the number of previous deliveries (χ(2)(trend) = 4318.91, P < 0.01). Many fetal deaths were associated with birth defects. We found several demographic characteristics associated with fetal deaths from birth defects, which may be related to the severity of the birth defects, economic and medical conditions, and parental attitudes toward birth defects.