Maternal Age at Birth and Gastroschisis Prevalence in the United States and Puerto Rico, 2000-2020.

Gastroschisis-a congenital anomaly where there is an opening at the connection of the embryonic ectoderm and the amnion at the pars flaccida, resulting in the intestines protruding outside the body-is serious and requires surgical repair. The strongest risk factor is young maternal age. This study describes gastroschisis prevalence in the United States and Puerto Rico during 2000-2020 and indirectly examines whether prevalence patterns may be explained by maternal age trends. Using data from state and territorial surveillance systems (n = 46 total; n = 18 for all years), we expressed gastroschisis prevalence as 5-year averages, with moving averages every 2 years. We calculated the expected prevalence of gastroschisis by applying previously published maternal age-based estimates to all US live births during 2000-2020. Gastroschisis prevalence has increased since 2000-2004, peaked during 2008-2012 (based on active surveillance systems: 5.44 cases per 10 000 live births), and then declined until 2016-2020 (4.47 cases per 10 000 live births). Expected prevalence patterns were nearly identical. Gastroschisis prevalence patterns during the study period largely reflect the decline in US births among women aged <25 years rather than a substantial change in risk among younger women.