**4.4. Cord cysts**

Cord cysts have no clinical relevance and develop from the remnants of the allantois or the omphalomesenteric duct. The finding of an isolated umbilical cord cystic mass should lead to further detailed sonographic evaluation and karyotype testing should be done when IUGR or other anomalies are found [45]. The majority of first-trimester cysts are transient ultrasound findings that have no influence on pregnancy outcome [46]. The prognosis of persistent cysts appears to be similar to that of second-trimester cysts [47].

Several studies concluded that morphologic features of cord cyst (single, multiple) correlate with fetal abnormalities like abdominal wall defects and patent urachus [48].

Umbilical cord cysts are classified as true cysts or pseudocysts. True cysts have an incidence of 3.4% in first trimester of pregnancy and have no clinical significance, and are sometimes associated with fetal structural anomalies and aneuploidy [45]. True cysts are derived from the embryological remnants of either the allantois or the omphalomesenteric duct, are located typically toward the fetal insertion of the cord and range from 4 to 60 mm in size [49].

The exact cause of umbilical cyst is not known, but it is thought to be due to raised hydrostatic pressure in the umbilical vessels (**Figure 8**).

have a very polymorphic presentation and should be evaluated when the lesion contains cal-

Abnormalities of the Umbilical Cord http://dx.doi.org/10.5772/intechopen.72666 355

It can also be associated with severe fetal anomalies such as anencephaly, intestinal anomalies, and abdominal wall defects. The outcome in extragonadal teratomas can be affected by the presence of associated anomalies and surgical complications after correction of the con-

Angiomyxomas are benign solid masses which may be associated with fetal demise. Associated complications are premature delivery, cardiovascular anomalies, nonimmune hydrops fetalis, hydatidiform mole, polyhydramnios, and stillbirth [57]. The management of

Urachus represents a vestigial structure formed by the bladder dome and the obliterated umbilical arteries. Patent urachus represents 10–15% of all urachal anomalies in the literature [58] and may lead to urination through umbilicus and infections. It is a rare condition because urachal lumen typically closes at week 17 post-conception [59]. Alterations in the morphology of the umbilical cord should extend the investigation, since there are associations with chromosomal anomalies. It has been associated with bladder exstrophy and anterior abdominal

Congenital hernia of the umbilical cord (CHUC) is a rare congenital entity recognized as a distinct entity since the 1920s but is often misdiagnosed as a small omphalocele. During the first 5th–6th week of gestation, the bowel herniates into the developing umbilical cord and withdraws into the abdominal cavity until the 10th–12th week of gestation [60]. Return of

pregnancy with angiomyxoma in the third trimester is not well defined.

**6. Congenital hernia of the umbilical cord**

cifications [55].

genital malformations [56].

**5. Patent urachus**

wall defects.

**Figure 9.** Large umbilical cyst 3D view.

**Figure 8.** Large umbilical cyst in the second trimester.

Pseudocysts are more common than true cysts and can be located anywhere along the cord; they have no epithelial lining and represent localized edema and liquefaction of Wharton's jelly (known as Wharton jelly cysts). It is rarely possible to differentiate between true cysts and pseudocysts on ultrasound imaging [50]. But differentiation between the two entities is not very important because both are associated with anomalies. Pseudocysts are more common than true cysts and they are strongly associated with chromosomal defects and other congenital anomalies, especially omphalocele, hydrops, and trisomy 18 [51]. Usually, ultrasonography monitoring is sufficient, invasive tests not being typically needed. A higher risk of fetal anomalies is associated with the following: detection of cysts in the second or third trimester, persistence after the first trimester, large size, and location near fetal or placental end. Also, trisomy 18, 13, and 21 are known to be associated, in such cases, chromosomal analysis may be warranted [52].

They might be associated with omphalocele, Meckel's diverticulum, patent urachus, and hydronephrosis. False cysts are most commonly found at the fetal end of the cord, do not have an epithelial lining and might be associated with omphalocele, patent urachus, and chromosomal anomalies [53]. Twenty percent of cord cysts, no matter what type they are, are associated with structural or chromosomal anomalies [54].

When the umbilical cyst is detected antenatally, especially in second or third trimesters, it is recommended a detailed ultrasonographic examination of the fetus, and it should be carefully looked for any associated defects. In case of any suspicion should be done the karyotyping analysis.
