[Study on the distribution and related factors of birth weight of live births in Guangxi Zhuang Autonomous Region of China from 2016 to 2018].

Objective: To investigate the distribution and related factors of birth weight of live births and full-term infants in Guangxi Zhuang Autonomous Region of China. Methods: Based on Guangxi women and children information system from 2016 to 2018, a large real-time database about maternal and live-birth information was established. It covered 1 712 midwifery institutions in Guangxi. A total of 2 394 240 cases of live births were collected and 2 243 129 cases of which were full-term infants. The multivariate logistic regression model was used to analyze the related factors of low birth weight. Results: The birth weight of 2 394 240 live births, (3 123.49±461.08) g, in Guangxi was approximately normal distribution with a peak distribution to the left. The incidence of low birth weight was 8.05%, and the incidence of macrosomia was 2.07%. The incidence of low birth weight was 10.92% for the puerpera with body mass index (BMI, kg/m(2)) <18.5, 16.82% for the puerpera with height < 145 cm, 8.92% for the puerpera with age <20 years old, 7.67% for the puerpera with age ≥35 years old, and 54.65% for the puerpera with premature birth. The birth weight of 2 243 129 full-term infants, (3 176.01±400.78) g, was approximately normal distribution with a peak distribution to the right. The incidence of low birth weight was 2.97%, and the incidence of macrosomia was 2.19%. The incidence of low birth weight was 4.73% for puerpera with BMI<18.5, 8.17% for puerpera with height < 145 cm, 4.83% for puerpera with age <20 years old, and 3.05% for puerpera with age ≥35 years old. The risks of low birth weight [ OR (95 %CI ) value] of pregnant women aged <20, 25-29 and 30-34 years old were 1.31 (1.28-1.35), 0.88 (0.86-0.90) and 0.89 (0.87-0.91) times of those aged ≥35 years old. The risks of low birth weight [ OR (95 %CI ) value] of pregnancy BMI <18.5 and 18.5-23.9 kg/m(2) group were 1.98 (1.94-2.03) and 1.20 (1.18-1.23) times of those pregnancy BMI ≥24 kg/m(2). The risks of low birth weight [ OR (95 %CI ) value] of pregnant women's height (cm)<145, 145-154, 155-159 and 160-164 cm were 4.67 (4.39-4.97), 2.36 (2.29-2.44), 1.58 (1.53-1.63) and 1.22 (1.18-1.26) times of those heights ≥165 cm group. The risks of low birth weight [ OR (95 %CI ) value] of pregnant women's gestational age <28, 28-31 and 32-36 years old were 136.65 (124.33-150.20), 1 704.37 (1 509.02-1 925.02) and 33.45 (32.98-33.94) times of those gestational age ≥37 years old. Conclusion: The incidence of low birth weight of live births was higher in Guangxi from 2016 to 2018. There is a higher risk of low birth weight for younger, older, low height, low BMI and preterm women in Guangxi from 2016 to 2018.