Epidemiological Characteristics, Outcome Distribution and Pregnancy Risk Factors of Low Birth Weight with Birth Defects

This paper summarized the occurrence of low birth weight with birth defects in Xi'an, China, so as to provide a new scientific basis for further improving the birth defects surveillance system and reducing the incidence of birth defects. Data were collected from all the perinatal infants from 28-week-old fetuses to 7-day-old infants born in all the hospitals with obstetrical department in Xi’an from 2003 to 2014. 1957 cases of low birth weight with birth defects were surveyed. The gestational age distribution was 28-45w. The weight distribution was 100g-2500g. Single type birth defect rate was 77.2%. The proportion of premature infants<37W was 72.4%. The outcomes of low birth weight birth defects were 702 live births (36.8%), 1045 fetal deaths (54.7%), 86 stillbirths (4.5%) and 77 deaths within 7 days (4.0%), respectively. The five common types of birth defects were 320 cases of congenital hydrocephalus (16.3%), 267 cases of spina bifida (13.6%), 197 cases of congenital heart disease (10.1%), 164 cases of anencephaly (8.4%), 159 cases of cleft lip with cleft palate (8.1%). The difference between the outcomes of low birth weight with birth defects and those normal birth weight with birth defects (χ2=647.59,P<0.01). Exposure history in early pregnancy(χ2=3369.61, P<0.01), sickness during pregnancy(χ2=4040.38,P<0.01), medication during pregnancy(χ2=4331.43,P<0.01) and exposure to harmful substances during pregnancy (χ2=5764.97, P<0.01) were statistically significant between low birth weight with birth defects and normal weight with birth defects. Children with low birth weight birth defects are more likely to have adverse birth outcomes than those normal birth weight with birth defects. There is a statistical correlation between low birth weight infants with birth defects and maternal exposure to risk factors during pregnancy.