Pregnancy outcomes and prenatal traditional karyotype analysis with fetal omphalocele.

Background: Omphalocele is associated with many aneuploidies, deletions and congenital anomalies. This study evaluates pregnancies diagnosed with omphalocele and its relevance to concomitant genetic disorders.

Methods: The data of patients with the intrauterine diagnosis of omphalocele who had invasive diagnostic testing performed between January 2017 and January 2020 were evaluated retrospectively. The traditional karyotype analysis was performed to prenatal diagnosis for all fetuses. During the study period, all patients were scanned via ultrasonography by an experienced perinatologist, prenatally.

Results: We evaluated 22 cases of omphalocele whose genetic testing results were available. The mean maternal age was 25 (18-41) years. The median gestational week at diagnosis was 13 (11-22). Invasive genetic testing revealed aneuploidy in 7 patients (31.8%), 2 with trisomy 13 (9.1%), and 5 with trisomy 18 (22.8%). There were 5 fetuses (22.7%) that had extracorporeal liver: 1 had trisomy 18 (20%), 1 had trisomy 13 (20%), and the other 3 fetuses had a normal karyotype (60%). Further, 14 (63.6%) pregnancies were terminated: 4 had trisomy 18 (28.6%), 1 had trisomy 13 (7.1%), and 9 of the terminated pregnancies (64.3%) had additional congenital anomalies. There were 4 infants who died (50%) born from 8 patients who decided to continue with their pregnancy. The omphalocele sac of 1 infant spontaneously regressed in the ensuing weeks of pregnancy who is now 1 year old.

Conclusions: The chromosomal abnormalities presented in up to 31.8% of cases diagnosed with omphalocele. Moreover, for cases with normal genetic testing results, the propensity for additional structural defects was high and the prognosis remains poor. Counseling parents to consider their option of terminating the pregnancy is appropriate.