Prevalence and correlates of gastroschisis in 15 states, 1995 to 2005.

Gastroschisis, a congenital malformation causing the herniation of intestines and other abdominal organs outside of the fetal abdominal wall, continues to capture the attention of epidemiologists because of ongoing reports of the as-yet-unexplained increase in prevalence. Gastroschisis typically results in term or near-term live birth, with few comorbid congenital disorders.1–4 Whereas the cause of gastroschisis is unknown, identified risk factors include young maternal age with a lower body mass index (calculated as weight (kg)/[height (m)]2)5 and maternal race and ethnicity.6–8 Compared with foreign-born mothers, mothers born in the United States have a higher risk of having a neonate born with gastroschisis.9 Whereas estimates of prevalence of gastroschisis range from 2 to 3 cases per 10,000 live births, numerous reports indicate an increasing prevalence both in the United States and worldwide.1,8,10–15 Previous United States studies evaluating the trends and correlates of gastroschisis have been limited by the relatively rare occurrence. Small case counts may have prevented recognition of social, demographic, and clinical factors that might have provided information for prevention or intervention efforts. We therefore leveraged interstate collaboration within the National Birth Defects Prevention Network to pool data from a large, population-based, and nationally representative sample of gastroschisis cases over the course of 11 years to address the following research questions: What is the prevalence of gastroschisis in the United States?; Is there evidence to show that the prevalence has been increasing in the past two decades?; Are there subgroups of women at higher risk for having a neonate born with gastroschisis (eg, maternal age, racial, or ethnic groups)?; and Are there demographic (eg, sex of the newborn) or reproductive (eg, multiple gestations) characteristics associated with the occurrence of gastroschisis?