At the present time, the incidence of congenital digestive tract defects among mainland Chinese people is rarely reported. Our study presents up-to-date figures for prevalence of congenital digestive tract defects in the population of Jiaxing City, China. In order to evaluate the incidence of digestive tract malformation in this region most accurately, our study is mainly based on analysis of the local registered population in a specific region. This study describes in a standardized way, a large number of cases with digestive tract malformation by a total prevalence per 10,000 births.
Our results showed that the overall incidence of birth defects was 3.42%. A study by Wang  reported that the incidence in Jiaxing was 2.1% between 2006 and 2010. The increase in the prevalence may be due to different registration methods during our study period.
Compared with other regions and countries, the incidence of congenital digestive tract defects in Jiaxing City of this study was different (Table 5). According to previous reports, the rates of esophageal atresia in Europe (2.23–2.57 per 10,000 births from 1987–2006; 2.56 per 10,000 births from 1980–1988) [27, 28] and Hawaii (2.2 per 10,000 births from 1989–2000)  were higher than in Jiaxing. The prevalence of hypertrophic pyloric stenosis in Taiwan Region (3.9 per 10,000 births from 1997–2007)  and in Sweden (8.5 per 10,000 births from 1987–1996)  was higher than in the present study. However, the data in our study included hypertrophic pyloric stenosis in only one year; this warrants further investigation in the future. A previous study showed that the incidence of duodenal atresia in England was 0.7–1.8 per 10,000 births . Studies from Europe reported the overall incidence of Hirschsprung’s disease in Europe was 1.03–1.05 per 10,000 births  and in England was 1.33–1.98 per 10,000 births ; these findings are similar to the prevalence in our study (1.45 per 10,000 births). The prevalence of anorectal atresia/stricture in a worldwide survey in 2006 (2.0–6.67 per 10.000 births)  and in Europe (4.05 per 10,000 births)  was also similar to our study. Previous studies reported that the incidence of biliary atresia in Taiwan Region was 0.89–1.90 per 10,000 births , in Japan was 0.96 per 10,000 births , and in Korea was 0.93–1.19 per 10,000 births , while in New York it was 0.76–0.93 per 10,000 births  and in overall USA it was 0.65–0.85 per 10,000 births . The incidence in Jiaxing was similar to that in Taiwan Region. Several studies [35-37] have reported that biliary atresia is common in Asian countries, possibly attributed to racial and geographic factors. In addition, due to hypertrophic pyloric stenosis, Hirschsprung’s disease and biliary atresia are usually detected more than seven days after birth, and data collected in this study cannot exclude the omission of the registration of birth defects. For example, some cases developed symptoms after the first seven days since birth, and attended other hospitals for treatment. However, compared with previous studies, the incidence in this study was within a reasonable range. Furthermore, the differences in incidence between previous reports from other countries and China may be attributable to racial, environmental, and genetic factors.
Of the 76 cases with congenital digestive tract defects in our study, 68.4% survived. Different digestive tract abnormalities may affect survival. The general consensus is that live-born cases with associated malformations may have higher rates of mortality [40, 41]; in our study, 32.9% also congenital heart disease, and this may be a risk factor that reduces survival. Additionally, the incidence of digestive tract malformations in male infants was higher than in female infants (male: female=1.58:1), which was consistent with previous studies [42-44]. Compared with other congenital malformations, digestive tract defects are not easily detected immediately after birth, especially biliary atresia. In addition, the general population know little about congenital digestive tract defects, and it is necessary to educate patients about these diseases during the perinatal period and establish targeted prevention and awareness programs to prompt faster diagnosis and expedite treatment.
In the current study, although the association between preterm birth and congenital alimentary tract malformation was not assessed, more than a third of cases (39.2%) were premature births. Other studies have reported similar results. For example, a study of esophageal atresia in 23 European regions found that one third of live-born infants with isolated esophageal atresia were born preterm (gestational age <37 weeks) , and this was also demonstrated in a study regarding isolated anal anomalies . Some studies have also reported that low birth weight is associated with higher incidence of birth defects. Yoon et al.  found that the incidence of biliary atresia in infants weighing less than 2500g was higher than in infants of normal weight, and considered that low birth weight was an independent risk factor for biliary atresia. Digestive tract malformation will undoubtedly affect the normal function of a newborn’s digestive system, thereby hindering children’s digestion and absorption of nutrients. In tandem with these findings, our study showed that more than a third (40.8%) of the gastrointestinal malformation cases had lower birth weight than normal newborns. Most newborns with low birth weight are premature infants. Premature birth and low birth weight may be risk factors for the occurrence of digestive tract malformations. However, these findings require further investigation and research.
Our study had some limitations. Firstly, the database only covered a five-year period (2015–2019) of birth registration, meaning that our investigation utilized relatively short-term data. Secondly, newborn data in this study was not linked to maternal data, so it was not possible to consider or adjust for confounding factors such as perinatal health. In addition, congenital digestive tract defects are not easily diagnosed within seven days of birth, particularly hypertrophic pyloric stenosis, Hirschsprung’s disease, and biliary atresia. Therefore, there may have been omissions in the registration of birth defects in our study and some inaccuracy in the incidence estimates for biliary atresia. However, A major strength of this study was based on the population of a region in mainland China. The estimated incidence of congenital digestive tract malformations in mainland China is based upon studies that have been published abroad. There is little to no local information on this subject specific to China, and we believe more accurate local data will assist clinicians, researchers, and healthcare planners in providing better diagnostic and prognostic outcomes for newborns and their families by establishing awareness programs and increasing and expediting diagnosis and treatment. Our findings point out that digestive tract defects are not always established immediately after birth, which naturally impacts upon the health of the newborn, and these findings support and are supported by the findings of numerous other studies published throughout the world, though none relate to China at the same level of specificity as ours. In addition, we found that roughly one third of our subjects with digestive tract defects also had concomitant congenital heart disease, suggesting a link between the two which may warrant further investigation. China is a vast territory with a large and fluid population base, so it is difficult to compile very large sample reports focusing on digestive tract malformations. Thus, so far the prevalence of congenital digestive tract defects among Chinese people is rarely reported. This study fills a gap in the incidence of digestive tract malformations.