Transient omphalocele

Prenatal discovery of an omphalocele associated with an inner umbilical cord Meckel's diverticulum

The antenatal discovery of Meckel's diverticulum is a rare occurrence; the localization of both Meckel's diverticulum and omphalocele in the umbilical cord has never been described. We present herein a prenatal case of an omphalocele associated with inner umbilical cord dilated Meckel's diverticulum. An umbilical cord cyst was suspected with the cystic image seen during the first trimester exam, and sonography was repeated every month. Several possible diagnoses were discussed including umbilical cord cyst, omphalocele and umbilical cord hernia due to the changing sonographic images during pregnancy. Childbirth had to be arranged at a specialized center. After birth, clamping of the umbilical cord away from the base prevented iatrogenic atresia of the ileum. Surgical treatment had to be arranged during the first days of life.

Early detection of fetal structural abnormalities

Most published data on the detection of fetal anomalies at 11-14 weeks are from specialized centres with considerable experience in fetal anomaly scanning. However, there is still limited information on the feasibility and limitations of the screening of these anomalies compared with the now classical mid-gestation screening. This review indicates that overall, the detection rate of fetal anomalies at 11-14 weeks is 44% compared with 74% by the mid-pregnancy scan. Major abnormalities of the fetal head, abdominal wall and urinary tract, and of the umbilical cord and placenta, can be reliably detected at 10-11 weeks of gestation. Detection of other anomalies such as spina bifida, diaphragmatic hernia or heart defects is limited before 13 weeks of gestation. So far it cannot be stated that routine first trimester screening can be used on a large scale to evaluate the fetal spine and heart in the general population. In particular, in screening for congenital heart defects, the ability to perform a full cardiac examination increases from 20% at 11 weeks to 92% at 13 weeks. The early prenatal diagnosis of these anomalies may be improved by screening at 13-14 weeks rather than during the first trimester.

Fetal Omphalocele Detected Early in Pregnancy: Associated Anomalies and Outcomes

PURPOSE

To detect omphalocele and associated anomalies at ultrasonography (US) early in pregnancy and to describe the outcomes in fetuses with isolated and nonisolated omphalocele.

MATERIAL AND METHODS

Fetal endovaginal US was performed in 43,896 pregnant women at 12-16 weeks gestation. The women found to have fetal omphalocele were offered an amniocentesis to determine the fetal karyotype. For parents who decided to continue the pregnancy, repeat targeted transabdominal fetal US was performed at 20-24 weeks gestation. Additional follow-up US examinations performed until delivery were recommended. Postnatal pediatric examinations were performed in all of these fetuses. For the pregnancies in which no anomaly was detected at early US, the women were advised to undergo repeat US at about 24 weeks gestation for the detection of late-manifesting fetal anomalies. For pregnancies in which the baby was not delivered at the authors' affiliated hospital, the woman, her obstetrician, and her pediatrician were asked to inform the authors of any detected anomaly.

RESULTS

Omphalocele was visualized at US in 38 fetuses, who were categorized into two groups. One group consisted of 22 (58%) fetuses with associated structural anomalies. According to the karyotype determined for 18 of these fetuses, 11 of them also had chromosomal anomalies. The pregnancy was terminated at the parents' request in 19 of these 22 cases. There were two cases of missed abortion, and a small omphalocele in one fetus disappeared at 21 weeks gestation. The second group consisted of 16 (42%) fetuses with a normal karyotype and an omphalocele as an isolated US finding. In eight of these fetuses, the omphalocele disappeared at 20-24 weeks gestation and no defect was seen at delivery. In six other fetuses, omphalocele was identified at delivery. There was one case each of missed abortion and pregnancy termination. There were no false-negative diagnoses of omphalocele.

CONCLUSION

Isolated omphalocele diagnosed during the early stages of gestation typically has a good prognosis. In cases of a small defect, the anomaly may disappear later in the pregnancy.