Sacrococcygeal Teratoma (SCT)

A SCT can be detected through a routine ultrasound in the second trimester.  It will appear as a mass near the bottom of the back. A screening blood test may detect abnormally high levels of maternal alpha-fetoprotein, which can also alert your physician that a SCT may be present.

After the initial ultrasound or blood test, our team at the Cardinal Glennon St. Louis Fetal Care Institute will perform an in-depth evaluation to determine the extent of the tumor.  If a SCT is confirmed, we perform a targeted prenatal ultrasound and a fetal MRI to better examine the tumor and spine. Rarely, a small SCT may look like another birth defect called spina bifida. The MRI can help us make this distinction. Finally, we recommend a fetal echocardiogram. This specialized examination of the fetal heart will tell us how much strain is being put on the heart by the tumor.

If the tumor is small, we closely monitor your pregnancy, and your baby usually will not require any intervention until after birth. If the tumor is much larger and solid in nature, we will follow your baby very closely by ultrasound and echocardiogram. In this case, you may require intervention before or at birth.

In many cases, a SCT can cause complications for your baby. For example, it can steal blood flow away from your developing baby. If the tumor is small, this is not usually a problem, however for larger tumors, the additional blood flow needed to supply the tumor can cause a baby to develop heart failure (hydrops).

With SCT, a mother can also develop maternal mirror syndrome, where the mother starts to mirror symptoms of her sick infant —most commonly developing pre-eclampsia, which can be life-threatening if untreated.

One of the most common problems facing babies with large SCTs is premature birth. An infant with SCT often develops extra fluid in the uterus, or polyhydramnios. This problem, combined with signals from the baby, often results in premature loss of fluid and labor.

Treatment options available include:

Prenatal Surgery

In cases of severe SCT, fetal surgery may be considered. The goal of fetal surgery is to prevent fetal demise or premature delivery, and to repair heart failure. Options for fetal intervention are:

Open fetal surgery: The fetal surgeon makes an incision in the mother’s abdomen and uterus, similar to a cesarean section, and performs surgery to remove the tumor.  This life-saving treatment can repair severe SCT and heart failure.

Laser ablation: The fetal surgeon inserts a small needle through the uterus, into the fetus, and next to the blood vessels feeding the tumor. A laser fiber is inserted through the needle and laser energy is used to destroy the blood vessels. With less blood flow to the SCT, the fetal heart failure should improve and the tumor growth will slow.

For most babies with small SCT, we recommend cesarean delivery to prevent tumor bleeding. After delivery, a pediatric surgeon removes the tumor and reconstructs the bottom, and in most cases, the baby will recover fully.

For babies with large SCTs, the risk of tumor bleeding at delivery can be quite dangerous, especially if the baby is premature. This is why we often try to prevent bleeding and control the delivery by using an EXIT procedure. The EXIT is a controlled method of delivery where the mother is under general anesthesia and a cesarean incision is used to open the uterus and examine the baby. Since the placenta is still working and supporting the baby during an EXIT operation, the fetal surgeons have time to evaluate the tumor and decide if it should be removed immediately to prevent bleeding.

After delivery, either by EXIT or C-section, our goal is to stabilize your baby, especially from a breathing standpoint. If the tumor has not been removed and the lungs are working well, then surgery can be scheduled.

Your baby’s care after surgery will take place in the neonatal intensive care unit (NICU), where they will stay until they are breathing and eating well, and gaining weight. Most babies with SCT develop normally. Sometimes there are long-term issues such as constipation because the muscles around the anus were distorted by the tumor, but this can be managed easily with medicines. We follow babies with SCT over several years because there is a rare chance of recurrence. Blood tests, physical examination, and x-ray imaging are used to screen for recurrent tumors.

With proper prenatal care and monitoring, nearly all babies with SCT do well with surgery. Once your baby is stabilized, your baby can go home and ultimately achieve an excellent quality of life.