Isolated fetal omphalocele, Beckwith-Wiedemann syndrome, and assisted reproductive technologies.

OBJECTIVE

To assess the frequency of Beckwith-Wiedemann syndrome (BWS) among fetuses with an ultrasound diagnosis of isolated omphalocele and to examine relevant clinical variables, in particular route of conception.

MATERIALS AND

METHODS

An ultrasound and consultation database (1988-2007) was searched and cases were included that met the following criteria: omphalocele, no additional major structural anomaly or autosomal aneuploidy, and either newborn examination or molecular diagnostic studies for BWS. Medical records were reviewed and a nested case-control analysis matching day of birth assessed the route of conception, given the changing prevalence of assisted reproduction during the study period.

RESULTS

Thirty cases of isolated omphalocele were identified. Beckwith-Wiedemann syndrome was diagnosed in six cases (6/30 [20.0%]); four by newborn examination (4/6) and two on prenatal molecular studies (2/6). Of note, one case of BWS had a karyotype of 47,XXX, the remainder was euploid. Compared with isolated omphaloceles, fetuses with BWS more often were twins (3/6 vs. 1/24; p < 0.001), had polyhydramnios (4/6 vs. 2/24; p < 0.001), were macrosomic at birth (3/6 vs. 4/24 p < 0.001), and had been conceived by assisted reproduction (3/6 vs. 2/22; p = 0.04). When compared with normal controls matched by date of birth, conception by assisted reproductive technique among BWS births was highly significant, (p < 0001).

CONCLUSIONS

Beckwith-Wiedemann syndrome is present in a noteworthy portion of fetuses with isolated omphalocele on ultrasound, and prenatal molecular studies are warranted. Even among this small cohort, a recurring theme of conception by assisted reproduction exists.