The Fetal Center
Twin-Twin Transfusion Syndrome
View our Twin-Twin Transfusion Syndrome Fact Sheet »
View our Twin-Twin Transfusion Syndrome Fact Sheet in Spanish »
Twin pregnancies that share a common placenta (monochorionic twins) usually have blood vessel connections between the two fetuses. TTTS occurs in about 15% of these pregnancies when these blood vessels produce an imbalance or uneven sharing of the blood. As a result, blood from one twin (the "donor twin") is pumped to the other twin (the "recipient twin"). When this occurs, the heart of the donor twin must do extra work to support the recipient twin. The recipient twin gets too much blood and the donor twin does not get enough.
This unequal sharing of blood causes problems for both babies. The amniotic fluid level can be high for the recipient twin and low for the donor twin. Blood flow is going away from the donor twin who may become anemic (have a low blood count). The recipient twin can develop heart failure from having the burden of pumping extra blood. This may cause increased fluid to build up in the fetus that can lead to fetal death.
If left untreated, one or both twins may die. Because there are blood vessel connections in the placenta between the fetuses, one twin can be affected by death of the other twin. There is an increased risk of neurological complications or death in the remaining twin.
Once the condition has been detected, a targeted ultrasound will be performed to rule out the presence of anomalies in the twins. Amniocentesis may be recommended to look for chromosomal abnormalities and a specialized ultrasound of the fetal hearts, called an echocardiogram, may also be performed. TTTS is a progressive disease in which mild cases require only careful monitoring of twin growth and amniotic fluid. Severe cases in which one or both twins appear to be in danger may require fetal intervention.
Multiples Prenatal Care Algorithm »
Not every pregnancy with this condition will require fetal treatment. If it is determined that fetal intervention is the best option for your pregnancy, the team at the Center will develop a comprehensive plan for you and your babies during and after birth. All patients that have been diagnosed with TTTS should learn about potential fetal interventions. There are several treatment options available. Based on the severity of the case, your doctors at the Center will recommend the most appropriate treatment option.
The procedure is typically performed under regional (epidural or spinal) anesthesia. Afterwards, the mother will be admitted to the Women's Center at Children's Memorial Hermann Hospital to closely monitor the pregnancy. Medications and bed rest may be prescribed to minimize the risk of preterm labor. After discharge, mothers will continue to be followed by the Center and your obstetrician for ongoing care.
Type of delivery - The delivery plan will be carefully discussed with you and your obstetrician.
Place of delivery - If all of the prenatal monitoring suggests that your pregnancy is going well, the twins can be delivered at the hospital of your choice. However, the hospital should be prepared to handle any additional needs of your newborns and have a neonatal intensive care unit with the capability to provide specialized care.
Time of delivery - There is no reason to intentionally induce an early delivery. As long as the fetuses and mother are stable, the pregnancy should be allowed to proceed to term. If the twins' condition deteriorates, earlier delivery may be necessary.
Immediately following delivery, doctors will carefully evaluate and begin treatment if necessary. Most infants will be born without any problems. You and your loved ones should be able to immediately hold and bond with your newborns. If needed the babies will be stabilized in an intensive care unit and treated by the neonatologists (specialists in the care of high-risk newborns).
TTTS Follow Up Algorithm »
Babies will be followed for any signs or symptoms of neurologic complications. The multidisciplinary team at the Center will evaluate which treatment option is best for you and your pregnancy.
Dr. Anthony Johnson, Co-Director of theTexas Fetal Centeraffiliated withChildren's Memorial Hermann Hospital, visited the set of Great Day Houston to discuss diagnosis and treatment oftwin to twin transfusion syndrome (TTTS).
Contact The Fetal Center to make an appointment with a high-risk pregnancy doctor.
Note: This information regarding your condition is meant to be a helpful, informative introduction. Because every newborn is different, this may not be applicable to all cases, especially if there are additional defects. Your team of experts at the Center will provide you with information specific to your pregnancy.
For immediate assistance,call 832.325.7288 or toll free at 1.888.818.4818