ﺑﺎﺯﮔﺸﺖ ﺑﻪ ﺻﻔﺤﻪ ﻗﺒﻠﯽ
خرید پکیج
تعداد آیتم قابل مشاهده باقیمانده : 3 مورد
نسخه الکترونیک
medimedia.ir

Omphalocele: Prenatal diagnosis and pregnancy management

Omphalocele: Prenatal diagnosis and pregnancy management
Literature review current through: Jan 2024.
This topic last updated: Apr 22, 2022.

INTRODUCTION — An omphalocele is a midline abdominal wall defect (absent skin, fascia, abdominal muscles) of variable size at the base of the umbilical cord. The defect is covered by a three-layer membranous sac consisting of amnion, Wharton's jelly, and peritoneum. The cord/umbilical vessels insert at the apex of the sac, which typically contains herniated abdominal contents (picture 1). Omphaloceles are categorized as either non-liver-containing (containing bowel loops) or liver-containing. Small defects generally can be closed in the first 24 to 72 hours of life. The remaining spectrum of defects usually involves some type of silo in the first 24 hours of life and delayed closure.

This topic will discuss issues related to omphalocele, primarily focusing upon prenatal diagnosis and pregnancy management. The other major fetal abdominal wall defect, gastroschisis, is reviewed separately. (See "Gastroschisis".)

EMBRYOLOGY AND PATHOGENESIS — Fetal abdominal wall defects result from disturbances in organogenesis during the embryonic period.

Normal embryologic development of the abdominal wall – During the fourth to fifth week of development, the flat embryonic disk folds in four directions and/or planes: cephalic, caudal, and right and left lateral. Each fold converges at the site of the umbilicus, thus obliterating the extraembryonic coelom. The lateral folds form the lateral portions of the abdominal wall, and the cephalic and caudal folds make up the epigastrium and hypogastrium [1,2]. Rapid growth of the intestines and liver also occurs concurrently.

During the sixth week of development (or eight weeks from the last menstrual period), the abdominal cavity temporarily becomes too small to accommodate its contents, resulting in protrusion of the midgut into the residual extraembryonic coelom at the base of the umbilical cord. This temporary herniation involves 90 degrees of counterclockwise rotation of the midgut around the superior mesenteric pedicle and is called physiologic midgut herniation. It is sonographically evident in the 9th to 11th postmenstrual weeks (up to crown rump length 45 mm) (image 1). Reduction of the hernia involves further rotation to 270 degrees in the abdominal cavity and normally occurs by the 12th postmenstrual week; thus, midgut herniation is no longer physiologic beyond the 12th week [3].

In contrast to the bowel, the liver does not undergo physiologic migration outside of the abdominal cavity during development. Therefore, the liver is never present in physiologic midgut herniation.

Pathogenesis – The pathogenesis of omphalocele has not been definitively established, but two mechanisms have been proposed. In one, the extraembryonic gut fails to undergo the obligatory 270 degree counterclockwise rotation back into the abdomen, resulting in a simple, small, midline omphalocele [1,2,4].

In the other, failure of the left and right lateral folds to close normally creates a large abdominal wall defect through which contents of abdominal cavity (including the liver) can herniate [1,2]. In addition, the rectus abdominis muscles insert laterally into the costal margins instead of meeting in the midline at the xiphoid.

PREVALENCE AND EPIDEMIOLOGY — Omphalocele and gastroschisis are the most common fetal abdominal wall defects in the United States, with prevalences of approximately 2 and 4 per 10,000 live births, respectively [5], consistent with the worldwide omphalocele prevalence of 2.6 per 10,000 births [6]. The prevalence of gastroschisis appears to be increasing at a faster rate than that of omphalocele [7].

The occurrence of omphalocele appears to be more common in offspring of mothers at the extremes of reproductive age [8,9]. In mothers <20 or >40 years of age, the odds of omphalocele in offspring are more than doubled compared with the general obstetric population: odds ratio (OR) 2.45 (95% CI 1.22-4.86) and OR 8.76 (95% CI 4.02-19.32), respectively [8]. The prevalence is slightly higher in Black than White patients (1.91 versus 1.47 per 10,000 live births) [10].

Modest associations between occurrence of omphalocele in offspring and maternal obesity and in utero selective serotonin reuptake inhibitor (SSRI) exposure have also been reported in some studies, while others have found no association [11,12]. Omphalocele has also been associated with male sex and multiple births [9].

PRENATAL (FETAL) DIAGNOSIS

Potential benefits — Prenatal diagnosis of an omphalocele can increase the chance of identifying some syndromes prenatally and provides time for parents to learn about and adjust to the abnormality; prepare for the needs of their offspring; and make arrangements to transfer to a center with prenatal, delivery, and/or neonatal care commensurate with maternal and/or neonatal needs. It also allows them the option of terminating the pregnancy.

Presentation — Omphalocele is typically diagnosed as part of an obstetric ultrasound examination performed for a standard indication (eg, fetal anatomic survey, pregnancy dating, assessment of nuchal translucency for Down syndrome screening). Over 90 percent are diagnosed prenatally [13].

Prenatal diagnosis of a non-liver-containing omphalocele can be made reliably after 12 postmenstrual weeks; prior to this time, unless large, omphalocele can be difficult to differentiate from physiologic midgut herniation.

Prenatal diagnosis of liver-containing omphalocele can be made by transvaginal sonography as early as 9 to 10 postmenstrual weeks if a homogenous mass measuring greater than 5 to 10 mm in diameter suggestive of liver is imaged within the area of physiologic midgut herniation [14-19]. The sonographic diagnosis of a liver-containing omphalocele can be made before the 12th postmenstrual week because herniated liver is never a normal developmental finding.

Findings on ultrasound — An omphalocele appears as a midline abdominal wall defect of variable size in the area of the umbilicus, covered by a membranous sac consisting of amnion as the outer layer, peritoneum as the inner layer, with Wharton's jelly in between, and containing abdominal contents (typically bowel [peristalsis can be observed] but often liver and occasionally stomach or bladder). The cord inserts into the apex of the sac. Ascites may be seen in the sac or the abdomen.

Eighty percent of omphaloceles contain part of the liver. The presence of the liver can be confirmed by using color Doppler to visualize the hepatic vessels or ductus venosus in the sac. The location of the liver is important, in part because the smallest omphaloceles are those that are bowel only, non-liver-containing omphaloceles. These small omphaloceles are commonly associated with a fetal aneuploidy, while the larger liver-containing omphaloceles are usually associated with euploid fetuses [20-22]. (See 'Associated abnormalities' below.)

The term "giant omphalocele" has been used to describe omphaloceles that contain most (>75 percent) of the liver or have a very large size (absolute size typically ≥5 cm or large size relative to the fetal abdomen), although "large" is variably defined [23,24].

Diagnostic images:

Ultrasound of normal umbilical cord insertion without and with color Doppler (image 2 and image 3)

Ultrasound of omphalocele at 12 weeks of gestation (image 4)

Ultrasound of omphalocele (containing liver) at 28 weeks of gestation (image 5)

Three-dimensional ultrasound of omphalocele at 15 weeks of gestation (image 6)

Associated abnormalities

Structural anomalies – Associated structural anomalies are common, generally ranging from 35 to 70 percent [25,26] but over 80 percent in some studies [27-30]. Associated abnormalities occurring with increased frequency include additional gastrointestinal abnormalities (eg, malrotation, intestinal or anal atresia), cardiac defects (eg, ventricular septal defect, tetralogy of Fallot, dextrocardia), genitourinary anomalies (eg, renal or bladder agenesis, polycystic kidney, hydronephrosis, ureteral stenosis/duplication/ectopic placement), orofacial clefts, neural tube defects, and diaphragmatic defects [9,14,15,29,31-34].

Chromosomal abnormalities – Omphaloceles containing only small intestine (ie, the liver is intracorporeal) are associated with a high frequency of fetal aneuploidy [20,35,36]. As many as 60 percent of these omphaloceles are associated with fetal aneuploidy, particularly trisomy 18 or 13 [22]. In one series of 250 fetuses with an omphalocele and an abnormal karyotype, the karyotypes included trisomy 18 (n = 158; 63 percent), trisomy 13 (n = 44; 17 percent), trisomy 21 (n = 9; 4 percent), Turner syndrome (n = 15; 6 percent), triploidy (n = 12; 5 percent), and rare chromosomal deletions (n = 12; 5 percent) [37].

The frequency of aneuploidy is higher in fetuses with more than one anatomic anomaly than in those with isolated omphalocele [23,27,30]. Fetuses with isolated omphalocele containing an extracorporeal liver are often euploid (90 percent in some studies) [20,21], but not invariably [38].

Amniotic fluid volume – Polyhydramnios is common after 20 weeks of gestation and was observed in over one-third of cases in one series [39].

Fetal growth restriction – An increased frequency of growth restriction has been reported in some studies. (See 'Prenatal care' below.)

Syndromes associated with omphalocele — Omphalocele has been associated with several syndromes (table 1), which can be categorized by the location of the midline abdominal wall defect in the upper, middle, or lower abdomen (table 2) [40-46].

In one series of almost 1500 newborns with omphalocele, the four most common genetic disorders identified were Beckwith-Wiedemann syndrome (BWS; 6 percent), trisomy 13 (3 percent), trisomy 18 (2 percent), and trisomy 21 (1 percent) [26]. The incidence of BWS is particularly high in fetuses with isolated omphalocele. In a single center series in which testing was consistently offered after exclusion of aneuploidy, BWS was diagnosed in 6 out of 16 (37.5 percent) fetuses with isolated and 1 out of 20 (5 percent) fetuses with nonisolated omphaloceles [47]. The genetics, clinical manifestations, and diagnosis of BWS are reviewed in detail separately. (See "Beckwith-Wiedemann syndrome".)

Differential diagnosis

Gastroschisis – Gastroschisis is the major disorder to consider in differential diagnosis of omphalocele. In most cases of gastroschisis, the abdominal wall defect is located to the right side of a normal appearing umbilical cord insertion site. The membranous sac of an omphalocele also helps to distinguish it from gastroschisis, which is characterized by loops of bowel free floating in amniotic fluid. However, omphalocele membranes occasionally rupture in utero, particularly in giant omphaloceles. In such cases, an extracorporeal liver and/or an umbilical defect site suggest an omphalocele, while an intracorporeal liver and a paraumbilical defect suggest gastroschisis. (See "Gastroschisis".)

Umbilical cord hernia – In an umbilical cord hernia, the umbilical cord inserts normally into the umbilical ring, which is surrounded by intact skin and is typically <2 cm in diameter, whereas in an omphalocele, the cord inserts into a membranous sac that covers a large abdominal wall defect occupying the area of the umbilical ring [48-50]. Like an omphalocele, the hernia is at the base of the umbilical cord. Also like an omphalocele, umbilical cord hernias can contain bowel, but in contrast to omphaloceles, they are not associated with an increased risk for anomalies or genetic syndromes. Pathogenesis is also probably different. Omphalocele is either a rotational abnormality or a primary failure of the four body folds to form a normal midabdominal wall, whereas in umbilical cord hernia, the body folds develop normally, but physiologic midgut herniation may persist and result in a simple hernia.

Other major abdominal wall defects in differential diagnosis, such as ectopia cordis, limb-body wall complex, cloacal exstrophy, Pentalogy of Cantrell, and urachal cyst, are rare (prevalence of each less than 1 in 100,000 births). They can be differentiated by their location (upper, middle, or lower abdomen), cord insertion, and associated abnormalities (table 2). Omphalocele and body stalk defects are both connected to the cord, but body stalk anomaly is also associated with scoliosis and a short umbilical cord. Ectopia cordis (and the Pentalogy of Cantrell) has at least a portion of the heart outside of the body cavity and is the classic upper midline abdominal wall defect. Bladder exstrophy develops below the cord insertion and is the classic lower midline abdominal wall defect.

Amniotic band sequence (ABS) can also result in abdominal wall disruption. Many times with ABS, other structures are involved beyond the abdominal wall, such as the cranium (eg, anencephaly, encephalocele), spine (eg, neural tube defect), and limbs (eg, amputations). (See "Amniotic band sequence".)

Associated maternal findings — The mother is asymptomatic. If a maternal serum alpha-fetoprotein concentration has been performed as part of screening for neural tube defects, it may be elevated [51,52].

POSTDIAGNOSTIC FETAL EVALUATION — After an omphalocele is diagnosed, further evaluation of the fetus may include:

Microarray

Echocardiogram

Testing for Beckwith-Wiedemann syndrome (BWS) after exclusion of aneuploidy

Microarray should be offered if an omphalocele or related body wall defects are identified prenatally because of the increased risk of aneuploidy, especially in cases with an intracorporeal liver or additional anomalies in other organ systems. (See "Prenatal genetic evaluation of the fetus with anomalies or soft markers".)

We suggest performing a fetal echocardiogram, given the increased incidence of cardiac abnormalities. (See "Congenital heart disease: Prenatal screening, diagnosis, and management", section on 'Indications for echocardiography'.) Magnetic resonance imaging is utilized on a case-by-case basis when it can provide additional information needed for pregnancy management.

Given the high risk of BWS in euploid fetuses with omphalocele, it is reasonable to offer testing for BWS, but this testing is complex and should be discussed with a geneticist [53]. We offer testing to all patients with fetal omphalocele (isolated or nonisolated) after confirmation of euploidy, recognizing that the risk for BWS is higher in isolated cases but still increased above baseline in nonisolated cases [47]. Methylation-sensitive multiplex ligation probe analysis (MS-MLPA) is the most robust method available for detecting the majority of epigenetic and genetic variations at 11p15 associated with this syndrome. These abnormalities include microdeletions, microduplications, alterations in gene dosage, DNA methylation at two imprinting centers, and uniparental disomy. (See "Beckwith-Wiedemann syndrome".)

If microarray and BWS testing are normal, fetal exome sequencing is an option, given that it increases the diagnostic yield in structurally abnormal fetuses by approximately 8 to 10 percent after normal microarray results [54]. Few data are available in patients with omphalocele [55,56]. In one study, three patients with non-isolated omphalocele and normal microarray accepted exome sequencing and one had a pathogenic variant [55]. This fetus had an omphalocele, cystic hygroma, spinal malformation, and short limbs and its mother had two similarly affected previous pregnancies.

PRENATAL CARE

Parental counseling — After the prenatal diagnosis of omphalocele is established, parents can benefit from the additional expertise and perspective provided by a team of maternal-fetal medicine specialists, neonatologists, pediatric surgeons, and genetic counselors working in collaboration.

Key issues for discussion include:

In utero therapeutic interventions are not available.

Although the omphalocele may appear to be an isolated anomaly prenatally, a substantial proportion of these fetuses will have associated abnormalities identified after birth (range 11 to 39 percent [53,57,58]). In one study of 87 fetuses with apparently isolated omphalocele and normal or untested karyotype, 61 percent were confirmed to have an isolated abnormality postnatally, while 13 percent had a cardiac abnormality, 11 percent had other abnormalities, 9 percent had Beckwith-Wiedemann syndrome (BWS), and 5 percent had another diagnosis (eg, gastroschisis, cloaca) postnatally [58].

Neonatal morbidity and mortality rates directly correlate with the presence and severity of associated anatomic and chromosomal anomalies [27,59-61]. Omphalocele associated with pulmonary hypoplasia from Pentalogy of Cantrell, trisomy 13 or 18, or triploidy generally carries a dismal prognosis. (See 'Outcome' below.)

If the parents choose to terminate the pregnancy, evaluation of the products of conception is recommended to confirm/determine the etiology of the omphalocele if unclear prenatally, as identifying a syndrome can be helpful in determining recurrence risk in future pregnancies.

The postnatal course can be difficult to predict. A primary repair may be possible, or repair can be a long and difficult process, involving multiple reconstructive procedures [62]. Poorer prognostic factors include an extracorporeal liver [63,64], large absolute or relative defect size (eg, ratio of omphalocele circumference/abdominal circumference [AC], ratio of defect diameter/widest diameter of the abdomen parallel to the defect), and the presence and type of additional congenital anomalies [65].

Fetal follow-up

Serial sonography to monitor fetal growth – In addition to routine prenatal care, we follow most pregnancies complicated by omphalocele with serial ultrasound examinations every three to four weeks to evaluate fetal growth. Fetal growth restriction is common in pregnancies complicated by an omphalocele, particularly with associated abnormalities [63,66,67], and predictive of an increased risk of adverse neonatal outcome [63]. Because the most commonly used formulas for estimating fetal weight rely heavily on the measurement of abdominal circumference (AC), these formulas tend to underestimate the weight of these fetuses. Therefore, when AC is small and discordant with estimated gestational age, we look closely at the size and growth velocity of other biometric parameters (eg, femur length, biparietal diameter) and amniotic fluid volume. If these findings are in the low normal range or are consistent with growth restriction, we perform umbilical artery Doppler. (See "Fetal growth restriction: Evaluation".)

Siemer and colleagues developed a specific formula for estimating fetal weight in fetuses with abdominal wall defects using the biparietal diameter, occipitofrontal diameter, and femur length measurements [68]. This formula may estimate fetal weight in these fetuses more accurately than formulas using AC [68-70] but is not widely used.

In patients with BWS who undergo serial ultrasound examinations after identification of omphalocele, other signs of BWS, such as fetal overgrowth, macroglossia, visceromegaly, and retrognathia, when present, are typically detected later in gestation [71].

Nonstress test/biophysical profile – When growth is appropriate and amniotic fluid volume is normal, we begin weekly nonstress testing or biophysical profile monitoring at 32 weeks of gestation to assess fetal well-being, as fetuses with omphalocele appear to be at increased risk of late fetal death [72,73]. We increase the frequency of fetal surveillance in pregnancies with additional complications, such as growth restriction, oligohydramnios, or nonisolated omphalocele. (See "Fetal growth restriction: Evaluation" and "Oligohydramnios: Etiology, diagnosis, and management in singleton gestations".)

Location, timing, and route of delivery

Location – Planning for delivery at a tertiary care center, as opposed to transporting a critically ill infant, provides optimal outcome for the newborn [25]. Increased morbidity in "out-born" neonates may be related to factors such as temperature and hydration status, initial care of the defect, and vascular compromise of prolapsed gut during prolonged transportation [74].

Timing – In the absence of standard indications for early delivery, expectant management is reasonable until spontaneous labor or at least 39+0 weeks of gestation. Preterm birth offers no advantage to affected neonates and is associated with increased morbidity and mortality. In one series of prenatally diagnosed isolated omphalocele, the only neonatal deaths occurred because of complications of prematurity [53]. As in other pregnancies, nonreassuring fetal testing and/or cessation of fetal growth at or near term is an indication for early delivery.

Route – No randomized trials evaluating the optimum route of delivery for these pregnancies have been performed. In most patients with omphalocele, we suggest a trial of labor and vaginal birth in the absence of standard indications for cesarean birth, as there is no strong evidence that cesarean birth improves outcome [25,75-78]. Our approach is based on a meta-analysis of 15 observational studies that found cesarean birth may be associated with an increased likelihood of primary repair (pooled relative risk [RR] 1.22, 95% CI 0.99-1.51) but no significant improvement in neonatal sepsis (pooled RR 0.70, 95% CI 0.30-1.62) or pediatric mortality (pooled RR 1.14, 95% CI 0.59-2.21) [79]. Furthermore, route of delivery was also not a factor in time until enteral feeding or length of hospital stay.

We recommend cesarean birth for fetuses with giant omphaloceles (defined as an omphalocele containing >75 percent of the liver or a defect greater than 5 cm) in an attempt to avoid dystocia, rupture, infection, and hemorrhage [80]. However, visceral trauma has also been reported after cesarean birth [76]. If a scheduled cesarean birth is performed, it should be at ≥39+0 weeks of gestation in the absence of standard indications for earlier delivery.

Outcome — A study using a prospectively collected database including almost 1500 infants with omphalocele discharged from 348 neonatal intensive care units in North America from 1997 to 2012 reported the following outcomes [26]. No information was available on the frequency of pregnancy termination or the characteristics of these fetuses, which likely biases these findings.

60 percent of births occurred at term, and 28 percent occurred between 33 and 36 weeks. The increased frequency in preterm birth is related, in part, to preterm prelabor rupture of membranes.

35 percent of cases were associated with at least one other anomaly.

82 percent of live births survived to hospital discharge; the median length of hospitalization after birth in this group was 17 days.

9 percent had pulmonary hypertension, and one-half of these newborns received pulmonary vasodilating drugs.

The risk of infant death is as high as 45 percent in infants with pulmonary hypertension. The incidence of pulmonary hypertension appears to correlate with the size of the defect; it has been reported in 37 percent of infants with giant omphalocele, which can cause pulmonary hypoplasia [81].

APPROACH TO THE NEONATE

Delivery room — In the delivery room, the key is to avoid clamping the umbilical sac. (In umbilical cord hernias, it is important to avoid clamping the proximal part of the umbilical cord, which may contain occult herniated bowel.)

The immediate care of the newborn with omphalocele involves [25,82]:

Sterile wrapping of the bowel to preserve heat and minimize insensible fluid loss

Insertion of an orogastric tube to decompress the stomach

Stabilizing the airway to ensure adequate ventilation

Establishing peripheral intravenous access

Positioning left-side down right-side up if low blood pressure, tachycardia, or dusky bowel appearance suggesting vascular compromise

One approach is to place gauze dressings soaked in warm sterile saline and cover the dressing with clear plastic wrap; some use a plastic bag that encloses the infant up to the chest. Excessively wet and circumferential dressings should be avoided because they can macerate the omphalocele sac and cause the newborn's temperature to drop [82]. Circumferential abdominal wall wraps also should be avoided, as they have the potential to compromise blood flow.

Intravenous fluids and broad spectrum antibiotics are administered [82]. Cardiorespiratory and fluid status should be monitored closely and a thorough physical examination performed to identify additional malformations. The neonate should be maintained in a thermoneutral environment.

Synopsis of surgical management — The priority for abdominal wall repair is preservation of intestinal blood flow. In all cases, the size of the abdominal wall defect must be balanced with right of domain (ie, anteroposterior depth of abdominal cavity). In general, small defects (2 to 3 cm) can be repaired in the first 24 to 72 hours of life by primary closure of both fascia and skin. The remaining spectrum of defects usually involves some type of silo in the first 24 hours of life and delayed closure. The silo can be reduced gradually over three to seven days in the intensive care unit, after which the infant is returned to the operating room for final closure of the abdominal wall [82,83]. Reducing a large defect or one that contains an anatomically kinked liver can be done with Doppler ultrasound guidance to ensure the vena cava and hepatic outflow are not compromised during the silo reduction. Giant omphaloceles (ie, containing >75 percent of the liver or defect greater than 5 cm) may be managed by a combination of silo, acellular dermal patch, and skin graft or by promoting formation of an amniotic sac eschar by application of a sclerosing solution (topical povidone-iodine), with delayed hernia repair.

After omphalocele reduction, the neonate may require prolonged mechanical ventilation because of respiratory difficulties and caval compression. Postoperative increase in intra-abdominal pressure required to restore intestinal right of domain must be carefully monitored through urine output, pulse rate, and blood pressure [25,80]. Infants with very large omphaloceles containing most of the liver may require multiple reconstructive procedures and have the potential for long-term morbidity [80]. Nutritional status, associated anomalies, and pulmonary hypoplasia all play major roles in determining whether the child will have a good long-term outcome [84].

RISK OF RECURRENCE IN FUTURE PREGNANCY — The recurrence risk is dependent on the underlying cause.

Most cases of omphalocele are sporadic. For isolated omphalocele with a normal fetal karyotype, the recurrence risk is less than 1 percent [85].

For omphalocele with a trisomic karyotype, the recurrence risk is 1 percent but increases if a parental balanced translocation is detected.

For omphalocele with Beckwith-Wiedemann syndrome (BWS), microarray should be performed to look for duplications or abnormalities of chromosome 11p15. Familial cases of BWS can be autosomal dominant and have a 50 percent recurrence risk. (See "Beckwith-Wiedemann syndrome", section on 'Genetics and pathogenesis' and "Beckwith-Wiedemann syndrome", section on 'Genetic testing' and "Beckwith-Wiedemann syndrome", section on 'Genetic counseling'.)

SUMMARY AND RECOMMENDATIONS

Definition and diagnosis – An omphalocele is a type of abdominal wall defect (picture 1). The prenatal diagnosis is based on ultrasound examination and made in a fetus with a midline abdominal wall defect of variable size in the area of the umbilicus, covered by a membranous sac, and containing herniated abdominal contents (typically bowel, but often liver, and occasionally stomach or bladder) (image 5 and image 6). The cord inserts into the apex of the sac. Ascites may be seen in the sac or the abdomen. (See 'Findings on ultrasound' above.)

A “giant” omphalocele can be defined as an omphalocele containing >75 percent of the liver or a defect greater than 5 cm. (See 'Findings on ultrasound' above.)

Prenatal ultrasound examination can detect almost all cases of omphalocele and define associated anomalies, which can occur in any organ system and can be syndromic. (See 'Associated abnormalities' above and 'Syndromes associated with omphalocele' above.)

Differential diagnosis – Gastroschisis is the major disorder to consider in differential diagnosis. It can be differentiated from omphalocele by its absence of a membranous sac and its paraumbilical (rather than umbilical) cord insertion site (image 7 and image 8). (See 'Differential diagnosis' above.)

Postdiagnostic evaluation – Postdiagnostic evaluation of fetuses with omphalocele includes (see 'Postdiagnostic fetal evaluation' above):

Fetal chromosomal microarray, because of the increased risk of aneuploidy. An isolated omphalocele containing liver is usually associated with fetal euploidy, whereas associated anomalies and an intracorporeal liver are commonly associated with aneuploidy.

Echocardiogram

Testing for Beckwith-Wiedemann syndrome in euploid fetuses.

Pregnancy management

Fetal surveillance – When growth is appropriate and amniotic fluid volume is normal, we begin weekly nonstress testing or biophysical profile monitoring at 32 weeks of gestation to assess fetal well-being. We increase the frequency of fetal surveillance in pregnancies with additional complications, such as growth restriction, oligohydramnios, or nonisolated omphalocele. (See 'Fetal follow-up' above.)

Timing of birth – In the absence of standard indications for early delivery, expectant management is reasonable until spontaneous labor or at least 39 weeks of gestation. Preterm birth offers no advantage to affected neonates and is associated with increased morbidity and mortality. (See 'Location, timing, and route of delivery' above.)

Route of birth – For most patients with fetuses with omphalocele, we suggest a trial of labor (Grade 2C). We perform a cesarean birth in selected cases, including fetuses with giant omphalocele. (See 'Location, timing, and route of delivery' above.)

Care of the newborn – Ideally, delivery should occur at a tertiary care center with the appropriate level of neonatal medical and surgical care. In the delivery room, neonatal management involves covering the defect with gauze dressings soaked in thermally neutral sterile saline, covering the dressing with clear plastic wrap, inserting an orogastric tube to decompress the stomach, stabilizing the airway to ensure adequate ventilation, and establishing peripheral intravenous access. (See 'Approach to the neonate' above.)

Outcome – Overall survival of live born infants is approximately 90 percent. This high rate reflects the ability to diagnose abdominal wall defects prenatally and the decision of many families to proceed with termination of pregnancy when the defect is severe or multiple associated anomalies are present. (See 'Parental counseling' above.)

Recurrence risk – Most cases of omphalocele are sporadic. Recurrence risk depends on the cause. (See 'Risk of recurrence in future pregnancy' above.)

  1. Duhamel B. Embryology of Exomphalos and Allied Malformations. Arch Dis Child 1963; 38:142.
  2. HUTCHIN P. SOMATIC ANOMALIES OF THE UMBILICUS AND ANTERIOR ABDOMINAL WALL. Surg Gynecol Obstet 1965; 120:1075.
  3. Cyr DR, Mack LA, Schoenecker SA, et al. Bowel migration in the normal fetus: US detection. Radiology 1986; 161:119.
  4. Margulis L. Omphalocele (amnicele). Am J Obstet Gynecol 1945; 49:695.
  5. Stallings EB, Isenburg JL, Short TD, et al. Population-based birth defects data in the United States, 2012-2016: A focus on abdominal wall defects. Birth Defects Res 2019; 111:1436.
  6. Nembhard WN, Bergman JEH, Politis MD, et al. A multi-country study of prevalence and early childhood mortality among children with omphalocele. Birth Defects Res 2020; 112:1787.
  7. St Louis AM, Kim K, Browne ML, et al. Prevalence trends of selected major birth defects: A multi-state population-based retrospective study, United States, 1999 to 2007. Birth Defects Res 2017; 109:1442.
  8. Byron-Scott R, Haan E, Chan A, et al. A population-based study of abdominal wall defects in South Australia and Western Australia. Paediatr Perinat Epidemiol 1998; 12:136.
  9. Marshall J, Salemi JL, Tanner JP, et al. Prevalence, Correlates, and Outcomes of Omphalocele in the United States, 1995-2005. Obstet Gynecol 2015; 126:284.
  10. Kirby RS. The prevalence of selected major birth defects in the United States. Semin Perinatol 2017; 41:338.
  11. Waller DK, Shaw GM, Rasmussen SA, et al. Prepregnancy obesity as a risk factor for structural birth defects. Arch Pediatr Adolesc Med 2007; 161:745.
  12. Alwan S, Reefhuis J, Rasmussen SA, et al. Use of selective serotonin-reuptake inhibitors in pregnancy and the risk of birth defects. N Engl J Med 2007; 356:2684.
  13. EUROCAT Prenatal Detection Rates. EUROCAT Website Database. http://www.eurocat-network.eu/PrenatalScreeningAndDiagnosis/PrenatalDetectionRates (Accessed on May 03, 2019).
  14. Khoury MJ, Erickson JD, Cordero JF, McCarthy BJ. Congenital malformations and intrauterine growth retardation: a population study. Pediatrics 1988; 82:83.
  15. Romero R, et al. Omphalocele. In: Prenatal diagnosis of congenital anomalies, Romero R, et al (Eds), Appleton & Lange, Norwalk 1998. p.220.
  16. Curtis JA, Watson L. Sonographic diagnosis of omphalocele in the first trimester of fetal gestation. J Ultrasound Med 1988; 7:97.
  17. Brown DL, Emerson DS, Shulman LP, Carson SA. Sonographic diagnosis of omphalocele during 10th week of gestation. AJR Am J Roentgenol 1989; 153:825.
  18. Gray DL, Martin CM, Crane JP. Differential diagnosis of first trimester ventral wall defect. J Ultrasound Med 1989; 8:255.
  19. Pagliano M, Mossetti M, Ragno P. Echographic diagnosis of omphalocele in the first trimester of pregnancy. J Clin Ultrasound 1990; 18:658.
  20. Nyberg DA, Fitzsimmons J, Mack LA, et al. Chromosomal abnormalities in fetuses with omphalocele. Significance of omphalocele contents. J Ultrasound Med 1989; 8:299.
  21. Benacerraf BR, Saltzman DH, Estroff JA, Frigoletto FD Jr. Abnormal karyotype of fetuses with omphalocele: prediction based on omphalocele contents. Obstet Gynecol 1990; 75:317.
  22. van Zalen-Sprock RM, Vugt JM, van Geijn HP. First-trimester sonography of physiological midgut herniation and early diagnosis of omphalocele. Prenat Diagn 1997; 17:511.
  23. Kleinrouweler CE, Kuijper CF, van Zalen-Sprock MM, et al. Characteristics and outcome and the omphalocele circumference/abdominal circumference ratio in prenatally diagnosed fetal omphalocele. Fetal Diagn Ther 2011; 30:60.
  24. Danzer E, Gerdes M, D'Agostino JA, et al. Prospective, interdisciplinary follow-up of children with prenatally diagnosed giant omphalocele: short-term neurodevelopmental outcome. J Pediatr Surg 2010; 45:718.
  25. Bianchi DW, Crombleholme TM, D'Alton ME. Omphalocele. In: Fetology, McGraw Hill, New York 2000. p.483.
  26. Corey KM, Hornik CP, Laughon MM, et al. Frequency of anomalies and hospital outcomes in infants with gastroschisis and omphalocele. Early Hum Dev 2014; 90:421.
  27. Brantberg A, Blaas HG, Haugen SE, Eik-Nes SH. Characteristics and outcome of 90 cases of fetal omphalocele. Ultrasound Obstet Gynecol 2005; 26:527.
  28. Mayer T, Black R, Matlak ME, Johnson DG. Gastroschisis and omphalocele. An eight-year review. Ann Surg 1980; 192:783.
  29. Henrich K, Huemmer HP, Reingruber B, Weber PG. Gastroschisis and omphalocele: treatments and long-term outcomes. Pediatr Surg Int 2008; 24:167.
  30. Fleurke-Rozema H, van de Kamp K, Bakker M, et al. Prevalence, timing of diagnosis and pregnancy outcome of abdominal wall defects after the introduction of a national prenatal screening program. Prenat Diagn 2017; 37:383.
  31. Ardinger HH, Williamson RA, Grant S. Association of neural tube defects with omphalocele in chromosomally normal fetuses. Am J Med Genet 1987; 27:135.
  32. Fogel M, Copel JA, Cullen MT, et al. Congenital heart disease and fetal thoracoabdominal anomalies: associations in utero and the importance of cytogenetic analysis. Am J Perinatol 1991; 8:411.
  33. Crawford DC, Chapman MG, Allan LD. Echocardiography in the investigation of anterior abdominal wall defects in the fetus. Br J Obstet Gynaecol 1985; 92:1034.
  34. Tulloh RM, Tansey SP, Parashar K, et al. Echocardiographic screening in neonates undergoing surgery for selected gastrointestinal malformations. Arch Dis Child Fetal Neonatal Ed 1994; 70:F206.
  35. Duhamel B. Embryology of Exomphalos and Allied Malformations. Arch Dis Child 1963; 38:142.
  36. Sermer M, Benzie RJ, Pitson L, et al. Prenatal diagnosis and management of congenital defects of the anterior abdominal wall. Am J Obstet Gynecol 1987; 156:308.
  37. Lakasing L, Cicero S, Davenport M, et al. Current outcome of antenatally diagnosed exomphalos: an 11 year review. J Pediatr Surg 2006; 41:1403.
  38. Iacovella C, Contro E, Ghi T, et al. The effect of the contents of exomphalos and nuchal translucency at 11-14 weeks on the likelihood of associated chromosomal abnormality. Prenat Diagn 2012; 32:1066.
  39. Ozawa K, Ishikawa H, Maruyama Y, et al. Congenital omphalocele and polyhydramnios: a study of 52 cases. Fetal Diagn Ther 2011; 30:184.
  40. Kasznica J, Maldonado NM. Umbilical cord hernia, single umbilical artery, and lung hypoplasia in Ullrich-Turner syndrome. Am J Med Genet 1995; 57:496.
  41. Ranzini AC, Day-Salvatore D, Turner T, et al. Intrauterine growth and ultrasound findings in fetuses with Beckwith-Wiedemann syndrome. Obstet Gynecol 1997; 89:538.
  42. Saller DN Jr, Dailey JV, Doyle DL, et al. Turner syndrome associated with an omphalocele. Prenat Diagn 1993; 13:424.
  43. Stoll C, Alembik Y, Dott B, Roth MP. Risk factors in congenital abdominal wall defects (omphalocele and gastroschisi): a study in a series of 265,858 consecutive births. Ann Genet 2001; 44:201.
  44. Vasudevan PC, Cohen MC, Whitby EH, et al. The OEIS complex: two case reports that illustrate the spectrum of abnormalities and a review of the literature. Prenat Diagn 2006; 26:267.
  45. Nakagawa M, Hara M, Shibamoto Y. MRI findings in fetuses with an abdominal wall defect: gastroschisis, omphalocele, and cloacal exstrophy. Jpn J Radiol 2013; 31:153.
  46. Chen CP. Syndromes and disorders associated with omphalocele (III): single gene disorders, neural tube defects, diaphragmatic defects and others. Taiwan J Obstet Gynecol 2007; 46:111.
  47. Abbasi N, Moore A, Chiu P, et al. Prenatally diagnosed omphaloceles: Report of 92 cases and association with Beckwith-Wiedemann syndrome. Prenat Diagn 2021; 41:798.
  48. Haas J, Achiron R, Barzilay E, et al. Umbilical cord hernias: prenatal diagnosis and natural history. J Ultrasound Med 2011; 30:1629.
  49. İnce E, Temiz A, Ezer SS, et al. Poorly understood and often miscategorized congenital umbilical cord hernia: an alternative repair method. Hernia 2017; 21:449.
  50. Raju R, Satti M, Lee Q, Vettraino I. Congenital hernia of cord: an often misdiagnosed entity. BMJ Case Rep 2015; 2015.
  51. Saller DN Jr, Canick JA, Palomaki GE, et al. Second-trimester maternal serum alpha-fetoprotein, unconjugated estriol, and hCG levels in pregnancies with ventral wall defects. Obstet Gynecol 1994; 84:852.
  52. Morrow RJ, Whittle MJ, McNay MB, et al. Prenatal diagnosis and management of anterior abdominal wall defects in the west of Scotland. Prenat Diagn 1993; 13:111.
  53. Porter A, Benson CB, Hawley P, Wilkins-Haug L. Outcome of fetuses with a prenatal ultrasound diagnosis of isolated omphalocele. Prenat Diagn 2009; 29:668.
  54. Monaghan KG, Leach NT, Pekarek D, et al. The use of fetal exome sequencing in prenatal diagnosis: a points to consider document of the American College of Medical Genetics and Genomics (ACMG). Genet Med 2020; 22:675.
  55. Shi X, Tang H, Lu J, et al. Prenatal genetic diagnosis of omphalocele by karyotyping, chromosomal microarray analysis and exome sequencing. Ann Med 2021; 53:1285.
  56. Ozdemir H, Plamondon J, Gaskin P, et al. A prenatally diagnosed case of Donnai-Barrow syndrome: Highlighting the importance of whole exome sequencing in cases of consanguinity. Am J Med Genet A 2020; 182:289.
  57. Cohen-Overbeek TE, Tong WH, Hatzmann TR, et al. Omphalocele: comparison of outcome following prenatal or postnatal diagnosis. Ultrasound Obstet Gynecol 2010; 36:687.
  58. Grover R, Collins AL, Wellesley D. Exomphalos without other prenatally detected anomalies: Perinatal outcomes from 22 years of population-based data. Prenat Diagn 2020; 40:1310.
  59. Poznanski AK. Fetal omphalocele: prenatal US detection of concurrent anomalies and other predictors of outcome. Radiology 1990; 177:883.
  60. Hughes MD, Nyberg DA, Mack LA, Pretorius DH. Fetal omphalocele: prenatal US detection of concurrent anomalies and other predictors of outcome. Radiology 1989; 173:371.
  61. Heider AL, Strauss RA, Kuller JA. Omphalocele: clinical outcomes in cases with normal karyotypes. Am J Obstet Gynecol 2004; 190:135.
  62. Mitanchez D, Walter-Nicolet E, Humblot A, et al. Neonatal care in patients with giant ompholocele: arduous management but favorable outcomes. J Pediatr Surg 2010; 45:1727.
  63. Nicholas SS, Stamilio DM, Dicke JM, et al. Predicting adverse neonatal outcomes in fetuses with abdominal wall defects using prenatal risk factors. Am J Obstet Gynecol 2009; 201:383.e1.
  64. Tassin M, Descriaud C, Elie C, et al. Omphalocele in the first trimester: prediction of perinatal outcome. Prenat Diagn 2013; 33:497.
  65. Peters NC, Visser 't Hooft ME, Eggink AJ, et al. Prenatal Prediction of the Type of Omphalocele Closure by Different Medical Consultants. Fetal Diagn Ther 2016; 39:40.
  66. Hidaka N, Murata M, Yumoto Y, et al. Characteristics and perinatal course of prenatally diagnosed fetal abdominal wall defects managed in a tertiary center in Japan. J Obstet Gynaecol Res 2009; 35:40.
  67. Juhasz-Böss I, Goelz R, Solomayer EF, et al. Fetal and neonatal outcome in patients with anterior abdominal wall defects (gastroschisis and omphalocele). J Perinat Med 2011; 40:85.
  68. Siemer J, Hilbert A, Hart N, et al. Specific weight formula for fetuses with abdominal wall defects. Ultrasound Obstet Gynecol 2008; 31:397.
  69. Chaudhury P, Haeri S, Horton AL, et al. Ultrasound prediction of birthweight and growth restriction in fetal gastroschisis. Am J Obstet Gynecol 2010; 203:395.e1.
  70. Nicholas S, Tuuli MG, Dicke J, et al. Estimation of fetal weight in fetuses with abdominal wall defects: comparison of 2 recent sonographic formulas to the Hadlock formula. J Ultrasound Med 2010; 29:1069.
  71. Shieh HF, Estroff JA, Barnewolt CE, et al. Prenatal imaging throughout gestation in Beckwith-Wiedemann syndrome. Prenat Diagn 2019; 39:792.
  72. Deng K, Qiu J, Dai L, et al. Perinatal mortality in pregnancies with omphalocele: data from the Chinese national birth defects monitoring network, 1996-2006. BMC Pediatr 2014; 14:160.
  73. Heinke D, Nestoridi E, Hernandez-Diaz S, et al. Risk of Stillbirth for Fetuses With Specific Birth Defects. Obstet Gynecol 2020; 135:133.
  74. Kitchanan S, Patole SK, Muller R, Whitehall JS. Neonatal outcome of gastroschisis and exomphalos: a 10-year review. J Paediatr Child Health 2000; 36:428.
  75. Carpenter MW, Curci MR, Dibbins AW, Haddow JE. Perinatal management of ventral wall defects. Obstet Gynecol 1984; 64:646.
  76. How HY, Harris BJ, Pietrantoni M, et al. Is vaginal delivery preferable to elective cesarean delivery in fetuses with a known ventral wall defect? Am J Obstet Gynecol 2000; 182:1527.
  77. Moretti M, Khoury A, Rodriquez J, et al. The effect of mode of delivery on the perinatal outcome in fetuses with abdominal wall defects. Am J Obstet Gynecol 1990; 163:833.
  78. Lewis DF, Towers CV, Garite TJ, et al. Fetal gastroschisis and omphalocele: is cesarean section the best mode of delivery? Am J Obstet Gynecol 1990; 163:773.
  79. Segel SY, Marder SJ, Parry S, Macones GA. Fetal abdominal wall defects and mode of delivery: a systematic review. Obstet Gynecol 2001; 98:867.
  80. Biard JM, Wilson RD, Johnson MP, et al. Prenatally diagnosed giant omphaloceles: short- and long-term outcomes. Prenat Diagn 2004; 24:434.
  81. Partridge EA, Hanna BD, Panitch HB, et al. Pulmonary hypertension in giant omphalocele infants. J Pediatr Surg 2014; 49:1767.
  82. Townsend. Abdomen. In: Sabiston Textbook of Surgery, 16th ed, WB Saunders Co, Philadelphia 2001. p.1478.
  83. Pacilli M, Spitz L, Kiely EM, et al. Staged repair of giant omphalocele in the neonatal period. J Pediatr Surg 2005; 40:785.
  84. Roux N, Jakubowicz D, Salomon L, et al. Early surgical management for giant omphalocele: Results and prognostic factors. J Pediatr Surg 2018; 53:1908.
  85. Romero R. Prenatal Diagnosis of Congenital Anomalies, Appleton and Lange, East Norwalk CT 1988. p.220.
Topic 6763 Version 45.0

References

آیا می خواهید مدیلیب را به صفحه اصلی خود اضافه کنید؟