**3.9. Fetal cerebral ventriculomegaly**

## *3.9.1. Pregnancy management*

medical geneticist, pediatric neurologist, pediatric neurosurgeon, pediatric urologist, pediatric orthopedic surgeon). Long-term prognosis is related to the location of the NTD—the lower the defect, the better the prognosis [16]. In fetuses with myelomeningoceles, higher and larger lesions on MRI were significantly associated with full-time wheelchair use. High lesion level was associated with dysphagia. The absence of a covering membrane was associated with scoliosis and high-risk bladder dysfunction [28]. If the diagnosis is at less than 22–24 weeks of gestation, the opportunity of pregnancy termination can be offered to the parents. During prenatal counseling, discussion with the parents includes the natural history of myelomeningocele and the prenatal management decisions, including termination of the pregnancy, pursuit of additional prenatal testing, choice of delivery setting, and, when applicable, the possibility of fetal surgery. The postnatal management choices are also discussed, including surgical closure of the defect and possible need for ventriculoperitoneal shunt placement. Longitudinal follow-up after prenatal diagnosis of myelomeningocele suggests that approximately 60–70% of pregnancies end in termination or fetal

• Fetal intervention. Fetal surgery for myelomeningocele can arrest leakage of spinal fluid from the back and might therefore prevent or reverse herniation of the hindbrain (Chiari II malformation) and hydrocephalus [31]. Prenatal surgery for myelomeningocele reduced the need for shunting and improved motor outcomes at 30 months but was associated with maternal and fetal risks [32]. These benefits occurred despite a higher risk of preterm delivery and pulmonary complications among infants undergoing fetal surgery and of obstetrical complications, including placental abruption, dehiscence of the hysterotomy site, and maternal transfusion at delivery [32, 33]. Because fetal surgery is associated with risks of fetal and maternal complications, the family should be informed about the option of prenatal surgery, including the uncertainty regarding whether the risks of the procedure are outweighed by the potential benefits, particularly since longterm outcomes are not clearly known. Women with pregnancies complicated by fetal myelomeningocele who meet established criteria for in utero repair should be counseled in a nondirective fashion regarding all management options, including the possibility of open maternal-fetal surgery. Maternal-fetal surgery for myelomeningocele repair should be offered only to carefully selected patients at facilities with an appropriate level of personnel

For infants with a prenatal diagnosis of myelomeningocele who do not undergo fetal intervention, delivery should occur at a center with a level III NICU, pediatric neurosurgery services, and other personnel experienced in the neonatal management of these infants. Latex-free gloves and equipment should be used during delivery and subsequent care of the infant because patients with myelomeningocele are at risk for developing life-threatening

Term delivery is preferable, but increasing ventriculomegaly with macrocephaly on prenatal ultrasound may necessitate preterm delivery. Fetuses presenting in the breech position are

demise [29, 30].

478 Congenital Anomalies - From the Embryo to the Neonate

and resources [34].

*3.8.2. Delivery management*

latex allergy.

Fetal cerebral ventriculomegaly is a relatively common finding on second trimester obstetrical ultrasound examination. Many cases are associated with other abnormal findings, but in some fetuses, ventriculomegaly is the only abnormality [36]. Most children with isolated, mild ventriculomegaly have a normal outcome. The risk of abnormal outcome increases with the severity of ventriculomegaly, progression of ventriculomegaly, and presence of other anomalies. After ventriculomegaly is identified, further management involves identifying whether additional abnormalities (CNS and non-CNS) are present, diagnostic evaluation for the most common causes of ventriculomegaly, and counseling patients about the prognosis and potential pregnancy interventions. If the etiology of ventriculomegaly has been determined (e.g., trisomy, CMV) or associated malformations are identified, the parents can be given more specific information. Before viability, pregnancy termination is an option and should be offered.


mild ventriculomegaly may resolve by the third trimester; progression occurs in 16% of cases and has been associated with a worse outcome [36, 39]. Follow-up ultrasounds have detected fetal abnormalities not detected on the initial scan in 13% of cases [36]. Therefore, at least one additional detailed ultrasound examination should be performed between 28 and 34 weeks of gestation to look for CNS and non-CNS abnormalities and regression or progression of dilatation. Antepartum fetal testing has no proven benefit in pregnancies with isolated fetal ventriculomegaly in the absence of other findings, such as intrauterine growth restriction or oligohydramnios.

• Assessment for associated anomalies. Ultrafast fetal MRI to look for associated abnormalities and liver herniation and to estimate lung volumes and fetal echocardiography should

Management of Pregnancy and Delivery in Prenatally Diagnosed Congenital Anomalies

http://dx.doi.org/10.5772/intechopen.71802

481

CDH can be an isolated anomaly, part of a syndrome, or nonsyndromic but associated with other abnormalities. Approximately 50–70% of cases of CDH are isolated. Pulmonary hypoplasia, intestinal malrotation, and cardiac dextroposition are due to the hemodynamic or mechanical consequences of CDH; thus, they are usually considered part of the CDH sequence and do not negate the designation 'isolated CDH.' The other 30–50% of cases are called 'complex', 'nonisolated', or 'syndromic' CDH (CDH+) because they are associated with additional abnormalities, including major structural malformations, chromosomal abnormalities, and/ or single gene disorders. Malformations occur in all major organ systems, with no specific pattern [43]. An underlying syndrome is present in approximately 10% of CDH cases occurring with associated anomalies [43]. CDH is a prominent finding in the Fryns phenotype; facial dysmorphology, distal digital hypoplasia, and cardiac/renal/brain anomalies can also occur. CDH and diaphragmatic eventration are also an occasional component of many other syndromes, including Apert, Killian/Teschler-Nicola (Pallister-Killian), CHARGE, Coffin-Siris, Goltz, Perlman, Swyer, Brachmann-Cornelia De Lange, Goldenhar sequence, Beckwith Wiedemann, Simpson-Golabi-Behmel, Donnai-Barrow, Mathew-Wood, Jarcho-Levin, Fraser,

Associated anomalies are most common with bilateral CDH and in stillborn infants with CDH, where the prevalence is as high as 95% [43]. Anomalies in stillborn infants with CDH primarily consist of neural tube defects (anencephaly, myelomeningocele, hydrocephalus, and encephaloceles) and cardiac defects (ventriculoseptal defects, vascular rings, and coarcta-

• Genetic assessment. Chromosomal anomalies are identified in 10–20% of prenatally identified cases; the most common diagnoses include trisomies 18, 13, and 21 [43, 46]. Other karyotype abnormalities, such as monosomy X, tetrasomy 12 p (isochromosome 12p), partial trisomy 5, partial trisomy 20, and polyploidies, have also been reported [43, 47].

• Evaluation of prognostic factors for survival. Prognosis is worse in the setting of an abnormal chromosomal microarray, severe associated anomalies, right-sided defect, liver herniation, and lower fetal lung volume [43, 48]. The lung area to head circumference ratio (LHR) is more predictive of morbidity than mortality. A large defect is more likely to result in pulmonary hypoplasia and death than a small defect. The size of the defect is not measurable prenatally, so the presence of liver herniation and fetal lung volume measurements serves as a proxy for defect size [43]. Several other clinical findings for survival have not been confirmed (early gestational age at diagnosis, severe mediastinal shift, polyhydramnios, a small lung-thorax transverse area ratio, left ventricle/right ventricle index, left heart

Liver herniation is the most reliable prenatal predictor of postnatal survival. A systematic review of studies that used ultrasound or MRI to evaluate outcome of fetuses with liver herniation included 710 fetuses and reported significantly higher survival rate in fetuses without

be performed.

Stickler, Pierre Robin, and others [43, 44].

hypoplasia, and the stomach in the chest) [43].

tion of the aorta) [45].

• Fetal intervention. Intrauterine treatment with ventriculoamniotic shunting was performed in the 1980s. The expert consensus at that time was that these results did not represent an improvement in outcome over expectant management, which led to a de facto moratorium on such procedures [40]. At present, however, such procedures are investigational [36].

### *3.9.2. Delivery management*

Ventriculomegaly may or may not be accompanied by macrocephaly. Most infants with ventriculomegaly have a normal head circumference (HC), there is no increased risk of cephalopelvic disproportion, and cesarean delivery is not required except for standard obstetric complications. When the HC exceeds 40 cm, abdominal delivery should be considered.

Cephalocentesis, which almost always results in fetal death, is rarely used to decompress the head, allow vaginal delivery, and avoid maternal morbidity from cesarean delivery, in cases in which the neurological prognosis is so dismal (trisomy 13 or 18 or lethal co-existent anomalies) [41].
