UC Davis School of Medicine

A Publication of UC Davis School of Medicine

Volume 12 • No 3 • Winter 2015

New hope

Some of the fetal treatment options available through the new UC Davis Fetal Care and Treatment Center

twin infants twin infants


Spinana Bifida (Myelomeningocele)

The most serious form of spina bifida. The backbone protecting the developing spinal cord/neural tube does not close as it should, causing bulging of the cord and nerves and damage to both.

Impacts: Moderate-to-severe problems with leg movement and feeling, bowel and bladder complications, learning disabilities.

Options: Can be treated before birth in some circumstances, or after birth.


Accumulation of cerebrospinal fluid causes fluid-filled spaces or ventricles in the fetal brain to enlarge under pressure.

Impacts: Serious, long-term neurological damage without prompt treatment.

Options: Prenatal diagnostic information including fetal ultrasound and MRI can help inform treatment options, usually after birth.

Agenesis of the Corpus Callosum

Congenital abnormality of the main information pathway between the fetal brain’s two hemispheres.

Impacts: Mild to serious learning disabilities, congenital heart defects, cerebral palsy, mental disability, autism or seizure disorders.

Options: Prenatal diagnostic information including fetal ultrasound and MRI can help inform treatment options, usually after birth.


Congenital High-Airway Obstruction Syndrome (CHAOS)

Complete or near-complete obstruction of the upper airway.

Impacts: Lung hyperinflation and chest pressure compromise blood flow to and from the fetal heart, potentially resulting in abnormal fluid buildup.

Options: Treatment options include before birth or at time of birth via ex utero intrapartum treatment procedure/EXIT, where infant is partially delivered to permit surgical correction.

Congenital Pulmonary Airways Malformation (CPAM)

Masses or lesions that do not function as normal lung tissue. Previously known as congenital cystic adenomatoid malformation (CCAM).

Impacts: Can cause abnormal amounts of fluid buildup and swelling in the fetus and cause fetal death.

Options: Before birth if needed, at time of birth or after birth. Some can be treated with fetal medicines, others require fetal surgery.

Pulmonary Sequestration

A mass that may contain bronchi and alveoli but does not connect or function with the fetal lung.

Options: Most often treated after birth, but rarely may require treatment before birth to prevent fetal heart failure.


Lower Urinary Tract Obstruction

The fetus can’t urinate properly, causing the fetal bladder to become enlarged and distended and the amniotic sac to dry up.

Impacts: Back pressure can harm baby’s urinary system. Underdevelopment of kidneys and lungs.

Options: Bypass the blockage of urine while the baby is still in the womb, avoiding back pressure on the kidneys and enabling more normal lung development. Prenatal in utero treatment can be lifesaving for some fetuses.


Congenital Heart Disease

An abnormality in size, structure or function of the fetal heart, such as arrhythmias, holes between chambers, or valve problems leading to underdevelopment.

Impacts: If left untreated, can range from lifelong physical limitations to near-immediate infant mortality.

Options: Can be diagnosed in utero with ultrasound or echocardiogram. Structural problems are usually treated after birth, such as through staged reconstructive surgeries for hypoplastic left heart syndrome. Arrhythmias may respond to drug treatment during pregnancy.


TRAP Sequence or Acardiac Twin

Blood is delivered from one twin (the “pump” twin) to the other twin (“acardiac” twin) by backward flow.

Impacts: Acardiac twin receives oxygen-depleted blood. Can result in a variety of conditions threatening the life of the acardiac fetus, which cannot survive outside of the womb. Also creates up to 50–75 percent increased risk of death for pump twin due to strain on heart and/or premature delivery or miscarriage due to excess fluid or rapid swelling.

Options: Fetal radiofrequency ablation, laser or bipolar coagulation can prevent fetal death.

Twin-to-Twin Transfusion Syndrome

Blood flow becomes unbalanced between identical twins sharing a placenta.

Impacts: Smaller “donor” twin does not get enough blood, while the larger “recipient” twin receives too much. The recipient twin develops too much amniotic fluid and the donor low/absent fluid, becoming wrapped by its amniotic membrane.

Options: Fetoscopic laser intervention can save one or both twins.

Monochorionic Twins

Identical twins share a single placenta and a single amniotic sac, causing significant risk to the developing fetus.

Impacts: One twin can receive less share of placenta and grow differently, resulting in serious complications, such as twin-to-twin transfusion syndrome (TTTS).

Options: Monochorionic twins should be carefully evaluated to determine how the pregnancy is presenting and developing. Fetal laser treatment can save one or both fetuses.


Bowel Obstruction

Narrowing of the intestine that blocks normal flow of amniotic fluid, forcing it outside the baby into the uterus.

Options: Fetal diagnosis helps inform best treatment options for newborn. The child should be delivered in a hospital with an intensive care nursery and will undergo treatment to correct the blockage following delivery.

Congenital Diaphragmatic Hernia

Contents of the abdomen or bowel cavity herniate into the thoracic cavity housing the heart and lungs, preventing them from developing normally.

Impacts: After delivery, underdevelopment can become life-threatening.

Options: May be treated before birth in severe conditions, or after birth.


The abdominal wall develops improperly, allowing the contents of the fetal abdomen to herniate into surrounding amniotic fluid.

Impacts: Complications such as fetal growth restriction in utero, preterm birth and neonatal complications. The bowel can become irritated and occasionally permanently damaged.

Options: Surgery soon after birth returns organs to baby’s body and repairs abdominal wall. New non-operative “scarless” procedures may improve outcomes and are being tested.


The fetal intestines or other abdominal organs protrude outside of its body, usually through the umbilical area. They are covered by a thin layer of tissue and can readily be seen.

Impacts: The abdominal cavity might not grow to normal size to permanently house all organs. Infection is a concern, especially if the sac is broken.

Options: Usually treated after birth, but prenatal diagnosis helps inform those treatment options.


Amniotic Band Syndrome

Thin strands of tissue form inside the amniotic sac, entangling the fetus and trapping parts of its body.

Impacts: Pressure can affect growth and development. Most bands affect the extremities and only outer layers of soft tissue, but may sometimes go as deep as the bone and affect the head, face, or chest.

Options: Careful surgery in the womb releases the band and spares blood vessels and nerves. Fetal surgery can prevent limb loss before birth.

Sacrococcygeal Teratoma (SCT)

The most common congenital tumor, forming at the coccyx or tailbone.

Impacts: Can cause abnormal amounts of fluid buildup swelling in the fetus, and fetal death.

Options: When pronounced, can be treated prenatally with fetal surgery or following delivery.