Fetal Care
Sacrococcygeal Teratoma (SCT)

What is a Sacrococcygeal Teratoma?

A sacrococcygeal teratoma / SCT is a tumor that develops in a baby in utero. It appears in the lower back and buttocks of a baby at the base of the tailbone (coccyx). Some tumors are diagnosed in utero, others at birth.

Sacrococcygeal teratomas / SCTs are rare, occurring in about one in 35,000-40,000 births. However, in newborns with tumors, they are one of the most common types to develop. Females are four times more likely than males to be affected by these tumors. The cause of SCT is not known.

An SCT is a tumor that grows from germ cells, which are the same cells that give rise to a sperm or an egg. These tumors are made up of cells that can resemble any type of tissue in the body such as bone, nerve, teeth, muscle, and so on. These tumors can grow fast and become very large. They can be located both inside and outside the pelvis of a baby.

If your baby develops this type of tumor, you likely will not experience any symptoms early in the pregnancy. Later, the baby can develop illness quite rapidly and become very sick. In some instances, the mother can develop “maternal mirror syndrome” and become very sick as well.

Tumor Classification 

Sacrococcygeal teratomas / SCTs are grouped according to the amount of tumor present inside and/or outside the baby.

  • Type I tumors are completely external (outside the body) and easily identified during a prenatal ultrasound or at birth.
  • Type II tumors are mostly external but a portion is inside the body.
  • Type III tumors are mostly internal but a portion is outside the body.
  • Type IV tumors are completely inside the baby’s body and cannot be viewed externally. They are usually recognized late, and they have the highest rate of malignancy.

Most SCTs are benign (not cancerous).

What to Expect


The majority of SCTs are diagnosed in utero. This typically occurs early in the second trimester during a routine ultrasound when a mass can be seen on the baby’s buttocks.

It is at this point that most of our patients affected by SCT are referred to the Cincinnati Children's Fetal Care Center. Here, we’ll work with you to assess the severity of your case, create a plan for the remainder of your pregnancy, and help you understand what to expect after delivery.

These tumors sometimes grow quickly and reach a very large size. In order to grow, the tumor requires a lot of blood flow. As a result, your baby’s heart works hard to pump blood to the tumor. The larger the tumor, the harder the baby’s heart must work.

As the heart increases its output, the baby’s kidneys will also receive more blood flow and consequently make more urine. This increased urine production can lead to excessive amniotic fluid building up inside the uterus. This condition is called polyhydramnios and reflects a progression of the physiologic changes associated with SCT. Polyhydramnios is suspected if your uterus measures larger than it should at a given week in your pregnancy.

In the most severe cases, the tumor can grow so large that the baby’s heart can’t keep up, eventually leading to heart failure in the fetus (hydrops).


We typically see a mother with a fetal SCT within two weeks of her initial diagnosis. Your nurse-coordinator will speak with you and arrange the following tests and meetings during your visit.

  • An ultrasound of the baby, where we comprehensively look at the baby and specifically look at the blood supply, size and characteristics of the tumor
  • An MRI of the baby, to get more detailed views of the tumor, the baby’s spine and the surrounding structures in the baby’s pelvis
  • A fetal echocardiogram, to assess how hard your baby’s heart is working
  • A meeting with our social worker to assist with specific needs that you may have

After your tests are complete, our team of experts from maternal-fetal medicine (MFM), pediatric surgery, neonatology, genetics, cardiology and radiology will discuss the results and then meet with you in a team meeting. The important features of the team meeting include:

  • Introducing the care team that will be involved both before and after your baby is born
  • Reviewing the studies with you that led to the diagnosis and discuss their implications
  • Describing the options for prenatal treatment if needed
  • Developing a plan for the care of the rest of your pregnancy and the delivery
  • Describing the typical evaluation, treatment and long-term outcome for your baby after it is born

Compassionate, Expert Care 

The Fetal Care Center offers comprehensive diagnostic tests and the latest treatments for sacrococcygeal teratoma / SCT. Just as important, our team of specialists takes time to explain test results, answer questions and discuss treatment options. We understand that parents are facing unique challenges, and we provide as much support as possible every step of the way. Extensive experience and research allow our team to treat the most complex cases of SCT. 

Planning for Delivery 

You should deliver in a hospital with a level III neonatal intensive care unit (NICU) available for the specialized medical and surgical care that your baby will require after birth.

For patients who are local or plan to deliver locally, you will deliver at one of our maternity hospitals (University of Cincinnati Medical Center or Good Samaritan Hospital), and your baby will be transferred to the Cincinnati Children’s NICU.

Early delivery is common in pregnancies affected by SCT. Additionally, because of the typically large size and fragile nature of the tumor, in most cases we recommend delivery by cesarean section.

After your initial evaluation, if you choose to remain in our care, we will continue to follow your baby’s health closely with frequent ultrasounds and fetal echocardiograms. It also will be important to monitor your health with additional high-risk care. 

Even babies with small tumors can quickly become sick despite appearing to be well earlier in the pregnancy. As the pregnancy progresses, your risks increase for developing preterm labor, preeclampsia and maternal mirror syndrome. Therefore, after 30 weeks of pregnancy, your MFM may recommend an amniocentesis to assess the maturity of your baby’s lungs. If the lungs are adequately developed, an early delivery might be recommended to reduce the risks for your baby later in pregnancy.

Most cases of sacrococcygeal teratoma / SCT are treated after birth. Your baby will require surgery to remove the tumor within a day or two after delivery.

When the fetus becomes very sick but is too early to deliver, open fetal surgery may be an option. The procedure is called in utero debulking. “Debulking” means removing most of the tumor to reduce the strain on the baby’s heart.

For the in utero debulking, an incision will be made in the mother’s tummy and uterus. The baby’s bottom and legs will be brought out from the uterus allowing the surgeons to remove the external portion of the tumor. The remainder of the tumor will be removed during a surgery after your baby is born.

After the debulking, the baby is placed back into the uterus, and your uterus and tummy are closed. You are given medications to reduce the risk of preterm labor.

The goal of the procedure is to remove most of the tumor to reduce the stress on your baby’s heart. This allows your baby to recover while inside your uterus for the rest of the pregnancy.

Fetal surgery is not an option if the baby is so sick that it will not tolerate the operation or if there are signs of maternal mirror syndrome. Because mirror syndrome may be life threatening for the mother, immediate delivery is the best course of treatment in these cases.

After you deliver, your baby will be transferred to the NICU and stabilized. Once stabilized, within the first day or two of life, your baby will have surgery to remove the tumor.

While most SCTs are benign, some do become malignant (cancerous). With larger tumors, there is a slightly higher chance of malignancy or recurrence. These tumors tend to respond very well to chemotherapy.

The survival rate for babies undergoing open fetal surgery is approximately 50%. The survival rate for babies not needing fetal intervention is greater than 90%.

Your child will require follow-up care for at least the first three years of life to check for signs of recurrence. The majority of children born with SCT do well in terms of overall long-term health, but additional specialty care may be needed. Complications from SCT can include damage to the anus and rectum, injury to the pelvic muscles, bladder and bowel dysfunction, and problems of prematurity (often related to the development of the lungs). We partner with specialists throughout Cincinnati Children’s as needed to coordinate your baby’s care.

Our team approach means that your child’s care after birth will be managed by the same team you meet with during your initial evaluation. We make a special effort to coordinate and integrate your care with us from your first visit to after birth and beyond.

For More Information

For more information or to request an appointment, contact the Cincinnati Children's Fetal Care Center at 1-888-338-2559 or use our online form.

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Dyllon Has 6-Inch Tumor Removed at 2 Days Old

The sacrococcygeal teratoma tumor grew in utero from the base of his tailbone.