Twin-Twin Transfusion Syndrome (TTTS)

Twin-twin transfusion syndrome (TTTS) is a rare, serious condition that can occur in pregnancies. This happens when identical twins share a placenta (monochorionic). Abnormal blood vessel connections form in the placenta. They allow blood to flow unevenly between the fetuses. One twin − called the donor – becomes dehydrated. The other twin − called the recipient − develops high blood pressure. The recipient produces too much urine and over fills the amniotic sac.


TTTS is a disease of the placenta. It affects each twin differently. The donor twin does not produce as much urine as it should. This causes a low amount of amniotic fluid and poor fetal growth. The recipient twin has more urine than usual. This leads to an enlarged bladder and too much amniotic fluid. The extra fluid in the recipient fetus can put a strain on the heart. This can lead to heart failure. There is no known cause of TTTS.

Without treatment, this condition can be fatal for one or both twins. Fetal surgery is sometimes needed to treat the condition. The prognosis is better when TTTS develops after 20 weeks’ gestation.



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Twin-Twin Transfusion Syndrome (TTTS)

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What Is Twin-Twin Transfusion Syndrome (TTTS)?

Twin-twin transfusion syndrome (TTTS) is a rare, serious condition that can occur in pregnancies. This happens when identical twins share a placenta (monochorionic). Abnormal blood vessel connections form in the placenta. They allow blood to flow unevenly between the fetuses. One twin − called the donor – becomes dehydrated. The other twin − called the recipient − develops high blood pressure. The recipient produces too much urine and over fills the amniotic sac.

Medical animation of TTTS 

TTTS is a disease of the placenta. It affects each twin differently. The donor twin does not produce as much urine as it should. This causes a low amount of amniotic fluid and poor fetal growth. The recipient twin has more urine than usual. This leads to an enlarged bladder and too much amniotic fluid. The extra fluid in the recipient fetus can put a strain on the heart. This can lead to heart failure. There is no known cause of TTTS.

Without treatment, this condition can be fatal for one or both twins. Fetal surgery is sometimes needed to treat the condition. The prognosis is better when TTTS develops after 20 weeks’ gestation.

Getting a diagnosis of twin-twin transfusion syndrome is an emotional experience. Sometimes decisions about treatment must be made quickly. At the Cincinnati Children’s Fetal Care Center, we are here to help.

Evaluation & Diagnosis of TTTS

The Cincinnati Children's Fetal Care Center evaluates, gives a diagnosis, and recommendations for treatment in a one- or two-day visit. Surgery may take place within a day of the diagnosis.

When patients come to our center for an evaluation, the first step is to check for the presence of TTTS. We use ultrasound, fetal MRI, and fetal echocardiography (a detailed examination of both babies’ hearts by ultrasound) to give more information about the severity of the condition, which helps us recommend a treatment plan if TTTS is confirmed.

Staging Twin-Twin Transfusion Syndrome

Our team uses the Quintero staging system to figure out the severity of TTTS on a scale of one to five. Five being the most serious.

Stage I: One baby has too much fluid and the other baby does not have enough fluid.

Stage II: Cannot see the bladder fill in the donor fetus on ultrasound.

Stage III: Abnormal blood flow through the umbilical cord or fetal vessels around the heart for one or both babies.

Stage IV: An abnormal fluid collection in more than one body cavity, also known as hydrops. This can happen in one or both twins.

Stage V: The death of one or both babies.

Using the results of the fetal echocardiography, we also put the severity of the recipient fetus’ heart condition as mild, moderate or severe.

After the test results are available, the patient meets with members of the team. This team includes a maternal-fetal medicine specialist, a surgeon, and a nurse coordinator. We spend as much time with the patient and family in this meeting as needed. The goal is to explain the test results and create a treatment plan.

TTTS Treatment Options

The treatment plan we recommend depends on the severity of the condition and how far along the pregnancy is. Referring doctors can participate in this meeting, in person or by phone. We give them information about all parts of our evaluation, treatment and follow-up recommendations.