Prevalence, timing of diagnosis and pregnancy outcome of abdominal wall defects after the introduction of a national prenatal screening program

Objective: To examine prevalence, time of diagnosis and outcome of fetuses with an exomphalos or gastroschisis, diagnosed since the introduction of a national prenatal screening program in 2007. Methods: A prospective cohort study was undertaken in two fetal medicine units in the Netherlands. Cases were included if the estimated due date was between 2009 and 2013. Outcome measures were gestational age at diagnosis, presence of additional anomalies and pregnancy outcome. Results: A total of 141 exomphalos and 44 gastroschisis cases were included in the study, of which, respectively, 96 and 95% were diagnosed prenatally. The majority of the cases are visualized prior to the 20-week scan. In the exomphalos group, 83% had additional anomalies of which 57% had a chromosomal anomaly. Additional anomalies were present in 11% of the gastroschisis cases of which 40% had a chromosomal anomaly. The pregnancy termination rate was 61% (exomphalos) and 14% (gastroschisis). Conclusion: Almost all exomphalos and gastroschisis cases are diagnosed prenatally, the majority in the first trimester. Associated anomalies are far more common in exomphalos with a fourfold lower survival rate than gastroschisis. In the exomphalos group, the pregnancy termination rate doubled, while in the gastroschisis group the rate remained low.