Gastroschisis Prevalence and Co-occurring Malformations Among Danish Live Births During 1994-2021: A Nationwide Register-based Study

BACKGROUND: Gastroschisis prevalence has increased for decades with corresponding increases in the need for immediate and follow-up care. Such care can be complicated by presence of co-occurring malformations. This study explores prevalence of gastroschisis and co-occurring malformations among a 28-year cohort of Danish live-born infants.

METHODS: This retrospective cohort study used data from 1,695,992 infants born in Denmark during 1994-2021 and registered in the neonatal screening program. Infants were identified from the Danish Civil Registration System and Danish National Patient Register accessed through the Danish Biobank Register. Data on co-occurring malformations were ascertained to classify infants as syndromic or non-syndromic (either isolated or with co-occurring major malformations) and on selected infant and parental characteristics. Poisson regression models were used to estimate prevalence and corresponding 95% confidence intervals (CIs).

RESULTS: Prevalence (per 10,000 live births) of gastroschisis was 1.64 (CI: 1.45-1.84). Temporal trend analyses showed a statistically significant annual increase of 2.8% (CI: 1.4-3.3). Infants with gastroschisis most often presented as isolated (77.7%; CI: 72.3-82.5), followed by those with co-occurring malformations (21.9%; CI: 17.2-27.3) or a diagnosed syndrome (0.4%, CI: <0.1-2.0). Among infants with co-occurring malformations, cardiovascular (10.9%; CI: 6.8; 12.2) and intestinal (9.0%; CI: 5.9-12.2) malformations were most frequently recorded. Prevalence was higher among infants classified as premature but not influenced by infant sex or parental nativity.

CONCLUSION: Gastroschisis prevalence in Denmark increased during 1994-2021, similar to international reports, without increase in co-occurring malformations. Future work with this cohort will characterize healthcare received, comorbidities, and outcomes across the lifespan.

LEVELS OF EVIDENCE: Level III (High-quality prospective cohort study).