Hernia of the umbilical cord can be defined as a simple midgut failure to return from the umbilical celom to the peritoneal cavity at 10–12 weeks of gestation, so the defect has solely midgut unlike the other abdominal wall defects which can be defined as herniation of the abdominal viscera through an anterior abdominal wall defect. HUC described as < 4 cm in diameter has only midgut but never liver and covered by a membrane with a normal abdominal wall above the defect . All patients involved in this study were fulfilling the HUC criteria. The majority of patients in this study had a diameter of 2–3 cm; only one patient had a diameter of 3.5 cm. None of the cases involved in this study had contents other than the midgut, but it is worth to stress upon the presence of projecting cuff of the skin from the umbilical ring with the sac at the cord proximal end displacing Warton jelly as essential criteria of HUC.
HUC was first reported in researches by Hempel-Jorgensen in 1929, and he reported two cases in a family of this entity and had coined the term familial congenital umbilical hernia . After that, little case reports were published clearly describing this entity [10,11,12]. Proper antenatal diagnosis by ultrasound, amniocentesis, karyotyping, and amniotic fluid AFP needs to be done to differentiate between abdominal wall defects and other umbilical cord abnormalities. Moreover, this research did not record cases diagnosed by antenatal USG. Stanley et al.  used antenatal USG to differentiate omphalocele from HUC by the presence of the liver in the sac. Achiron et al.  reported that HUC happened at early embryological stage and diagnosed at early second trimester on antenatal USG. Sherer and Dar  diagnosed hematoma of the umbilical cord or excessive Wharton’s jelly after his antenatal USG observation as well as using karyotype, amniotic fluid, and AFP data. Elevated AFP in both amniotic fluid and maternal serum and raised amniotic fluid acetylcholinesterase associated with abdominal wall defects when myelomeningocele is absent . So, the existence of normal amniotic fluid, AFP, normal appearing abdominal umbilical cord insertion covered by echogenic non-membranous covering, with semisolid, semi-cystic lesion distal to insertion point, which at times may reveal peristalsis movement, and lack of associated anomalies can support HUC diagnosis. Meanwhile, pure omphaloceles, a more common lesion, have different prenatal ultrasonographic characteristics, as a wider base or stalk covered by a thin membrane and associated elevated amniotic fluid AFP, as well as a well-established high frequency of associated fetal chromosomal and structural anomalies . Prenatal diagnosis, as well as a thorough clinical evaluation, is critical in preventing intestinal injury during cord clamping during birth . The more recent obstetric literature reported no benefit of delivering these babies by cesarian Sect [17,18,19]. In this study, male preponderance (21 cases, 70%) was present which was in accordance with previous studies [9, 11].
There are four varieties of HUC: type 1 is a simple hernia into the cord with no accompanying consequences, type 2 is associated with intestinal obstruction, type 3 is linked with mucosal prolapse, and type 4 is associated with evisceration [20, 21]. Other related defects including the intestine atresia, persistent cloaca, Meckel’s diverticulum, small bowel syndrome, vitellointestinal duct persistence, and stenosis, glaucoma, congenital heart disease, and cleft lip and palate are rarely associated with HUC . There have been no reports of underlying genetic abnormalities associated with HUC up to now .
Our experience in the management of 30 neonates with HUC showed that the majority of patients (17 cases) had a simple classical HUC that was managed with full content reduction and non-surgical closure of defect by applying the umbilical clamp or vicryl tie at the base of HUC except for 3 of these usual cases where additional minor surgical intervention was needed. On the other hand, 13 patients presented with complicated unusual presentations and need surgical corrections. Postnatally, counseling and reassuring the parents and careful examination of umbilical defect should be done, and pediatric surgical referral should be considered to reach the proper diagnosis and reducibility of the contents. Choosing the proper line of management depends upon the umbilicus base as well as hernia contents, either by simple content reduction and sac ligation if the base is narrow and there is a short protrusion or by initial reduction, clamping, and immediate or later repair with cosmetic umbilicoplasty if the base is broad or there is a long-epithelialized protrusion around the umbilicus then surgical intervention is needed, but more mandatory if contents are not reducible or if there is bleeding or associated abnormalities that require surgical intervention. Once classical HUC was diagnosed, contents can be easily reduced by holding the sac upwards and doing gentle bowel milking into the peritoneal cavity. The fascia closed primarily, and cosmetic umbilicoplasty is always feasible which might be immediate or late. Care should be taken as the sac content is the midgut with or without the appendix, patent omphalomesenteric duct, or adhesions between the bowel and sac  as what is found in the present study cases.
In our experience and that of others, HUC can be accompanied with additional anomalies such as congenital short gut, PVID, and intestinal, ileal, and colonic atresia as a result of intrauterine vascular accidents such as intussusception and volvulus . In seldom cases, fetal demise is reported due to the rupture of the umbilical cord that led to in utero bowel evisceration and umbilical vessel rupture . In this respect, Klein et al. reported the umbilical cord hernias associated with malrotation of the intestine . Pal et al. described them as linked with cloacal anomalies, persistent vitello-intestinal duct, and atresia of the intestine . Haas et al.  in their case series of eight patients recommended that HUC is associated with bowel complications such as cysts of the umbilical cord, dilation of the intestine, short bowel, and ascites. The authors advocated for close monitoring and early induction of labor between 34 and 36 weeks of gestation. Gupta et al. described a case of congenital HUC coupled with type 3 ileal atresia . Pal et al. described an HUC case with gut perforation and extracelomic colonic atresia . Mirza et al. reported a case series of three HUC cases: one case associated with in utero evisceration of whole small bowel through presumably ruptured HUC and other 2 cases associated with patent vitellointestinal duct . In Patole1 et al. , most cases had ileal loops (49.42%) as the content of hernial sacs, 36.78% cases had Meckel’s diverticulum, and 6.39% had cecum with the appendix. Mortality was reduced to 3.33% with fast detection of the disease, early management, and good postnatal care.