Twin-to-Twin Transfusion Syndrome (TTTS) is a disease of the placenta. It affects pregnancies with monochorionic (shared placenta) multiples when blood passes disproportionately from one baby to the other through connecting blood vessels within their shared placenta. One baby, the recipient twin, gets too much blood overloading his or her cardiovascular system, and may die from heart failure. The other baby, the donor twin or stuck twin, does not get enough blood and may die from severe anemia. Left untreated, mortality rates near 100%.

Cause of Twin-to-Twin Transfusion Syndrome (TTTS)

The cause of TTTS is attributed to unbalanced flow of blood through vascular channels that connect the circulatory systems of each twin via the common placenta. The shunting of blood through the vascular communications leads to a net flow of blood from one twin (the donor) to the other twin (the recipient). The donor twin develops oligohydramnios (low amniotic fluid) and poor fetal growth, while the recipient twin develops polyhydramnios (excess amniotic fluid), heart failure, and hydrops. If left untreated, the pregnancy may be lost due to lack of blood getting to the smaller twin, fluid overload and heart failure in the larger twin, and/or preterm (early) labor leading to miscarriage of the entire pregnancy.

Some general treatment approaches consist of using laser energy to seal off the blood vessels that shunt blood between the fetuses. Because the surgical approach is via an operative fetoscope, there is minimal risk to the mother. Laser therapy for TTTS has been shown to provide improved pregnancy outcomes compared to alternative therapies. Although all treatment options should be discussed with your fetal surgeon.

Frequency of Twin-to-Twin Transfusion Syndrome (TTTS)

1 in 7 monochorionic pregnancies are afflicted with TTTS.

Diagnosis and Staging of Twin-to-Twin Transfusion Syndrome (TTTS)

The in utero diagnosis of TTTS is established by ultrasound. First, the presence of a shared placenta (monochorionic) confirmed. Ultrasounds performed earlier in the pregnancy may be useful in establishing the chorionicity (number of placentas). Ultrasound findings such as a single placenta, same fetal sex, and a "T-sign" in which the dividing membrane inserts perpendicular to the placenta are helpful in diagnosing a monochorionic twin gestation.

TTTS is then diagnosed simply by assessing the discordance of amniotic fluid volume on either side of the dividing fetal membranes. The maximum vertical pocket (MVP) of amniotic fluid volume must be greater than or equal to 8.0 centimeters in the recipient's sac, and less than or equal to 2.0 centimeters in the donor's sac.

Although TTTS is diagnosed via ultrasound, women with a monochorionic or monoamniotic pregnancy can be alerted to certain symptoms that may require medical attention. Symptoms may include a sudden increase in the size of the pregnant belly, a sudden increase in fatigue or pressure in the belly or back, and/or sudden unexplained increase in weight (eg. 7 lbs in a week or less).

Once the diagnosis of TTTS is established, the severity of the condition may be assessed using the Quintero Staging System, as listed below. This staging system is based on the observations of several hundred patients with TTTS. Not only does this staging system mirror the progression of disease, but it has also been shown to be important in establishing the prognosis. An atypical presentation of TTTS may occur if the fetal bladder of the donor twin remains visible despite the presence of critically abnormal fetal Dopplers or hydrops.

• Stage I: The fetal bladder of the donor twin remains visible sonographically.
• Stage II: The bladder of the donor twin is collapsed and not visible by ultrasound.
• Stage III: Critically abnormal fetal Doppler studies noted. This may include absent or reversed end-diastolic velocity (flow) in the umbilical artery, absent or reverse flow in the ductus venosus (liver), or pulsatile flow in the umbilical vein.
• Stage IV: Fetal hydrops present.
• Stage V: Demise of either twin.

Twin-to-Twin Transfusion Syndrome (TTTS) Treatment Options

Untreated, TTTS that presents before 28 weeks gestation is associated with approximately a 90% mortality rate. Because of the dismal prognosis of TTTS, various treatment methods have been advocated. Recent studies have shown improved outcomes in patients treated with laser therapy compared to the traditional method of serial amnioreductions (Quintero, AJOG, 2003; Senat, NEJM, 2004). In the European randomized trial, the study was interrupted prematurely because statistical improvement in pregnancy outcome in the laser therapy group was achieved at the time of an interval analysis (Senat, NEJM, 2004).

1. Laser Surgery: This surgical approach utilizes an operative fetoscope to deliver laser energy that then seals off the offending blood vessels on the surface of the common placenta. Because the vascular connections between the two fetuses are sealed, no further blood exchange between the fetuses takes place, thus eliminating the syndrome. Pregnancy outcomes after laser therapy for TTTS is as follows: approximately 85% of patients will have at least one fetus survive, 50% will have both survive, with a 5% risk of neurologic sequelae such as cerebral palsy. These results remain consistent regardless of Quintero Stage (i.e. severity).
2. Expectant Management: In this option the pregnancy would be followed with serial ultrasound examinations. There is approximately a 90% pregnancy loss rate in cases of TTTS diagnosed before 28 weeks gestation.
3. Amnioreduction: The purpose of this procedure is to remove excess amniotic fluid from the recipient's sac in order to prevent premature birth or miscarriage. This procedure is done via a needle placed using ultrasound guidance. Because this approach does not treat the underlying cause of TTTS, amniotic fluid excess may recur, resulting in the need for multiple amnioreductions. Overall, the success rate of this treatment approach is approximately 66% chance of at least one fetal survivor, with an incidence of 15% chance of brain damage. Unlike laser therapy, the risk of fetal death and neurologic sequelae increases with increasing Quintero Stage.
4. Fetal Septostomy: This procedure entails the purposeful needling of the dividing membrane in the hopes to equalize the amniotic fluid within each sac. Studies have not shown improved outcomes using this approach. Moreover, the disruption of the dividing membrane may result in cord entanglement, which may be an additional cause of fetal death. Genearlly this procedure is not advised.
5. Umbilical Cord Occlusion: This procedure utilizes an operative fetoscope to interrupt the flow of blood through the umbilical cord of one of the fetuses. This fetus dies and remains inside the uterus for the duration of the pregnancy. The remaining twin will have an 85% chance of survival, and 5% risk of brain damage. Because the risks of this procedure are similar to laser therapy, but laser therapy provides the additional benefit of the chance of survival for both twins, this procedure is generally not offered for the treatment of TTTS unless the demise of one twin is a foregone conclusion due to fetal anomolies and condition.

Twin-to-Twin Transfusion Syndrome (TTTS) Nutritional Information

If TTTS is diagnosed in its early stages some physicians will recommend a wait and see approach. Under this approach the mother is usually encouraged to consume increased amounts of protein, often through protein drinks like Boost or Ensure. Some physicians incorrectly indicate that TTTS can be "cured" by bed rest and proper nutrition (usually an increase in protein through protein drinks). Most studies indicate, regardless of a TTTS diagnosis, most pregnant women with multiples suffer malnutrition due to the nutritional needs of more than one fetus on the woman. Fetal Hope does promote proper nutrition including increase in nutritious foods such as fruit, vegetables and an increase in protein via lean meats and/or protein supplements. Providing proper nutrition to the pregnant mother will only allow her to be stronger for the pregnancy and for her babies to have more than adequate nutrition for their growth. Source: Fetal Hope Foundation

Fund Raising Events and Support Organizations

• Check out the TTTS Race For Hope - Denver, November 9, 2008 organized by the Fetal Hope Organization. The funds raised by the Race for Hope go to saving babies lives and giving hope to families by spreading awareness of Twin-to-Twin Transfusion Syndrome (TTTS) and other fetal syndromes, providing needed financial and emotional support to families, providing medical assistance and by funding medical research. Thousands of multiple pregnancies are affected each year in the U.S. and most cases result in the loss of one or both babies.
• Can't Come to the Run? Register for HUGS for HOPE!.Click here for more information or to register.
• Want to volunteer at the event? Contact Michelle Somers at 720.838.6185.
• Check out Muscle Mag Fitness Advisory Board Member, and Fetal Hope Foundation avid supporter Tom Terwillger who will be emceeing the event and be at the Post Race Sponsor Expo and NOMOTC Family Festival.

About the Fetal Hope Foundation

The Fetal Hope Foundation's mission is to provide support, provide information, fund research, increase awareness and be an outlet for leading medical information pertaining to fetal distresses and syndromes. In order to provide leading and accurate information, Fetal Hope’s organization contains a medical advisory board comprised of leading fetal medical centers and doctors. Fetal Hope is managed and run by those that have been affected directly and indirectly by various fetal syndromes.

Donate to the Fetal Hope Foundation

Send your donation via mail. Please make checks payable to "Fetal Hope Foundation" and mail to:  Fetal Hope Foundation, 9786 S. Holland St., Littleton, CO 80127.

To make a non-cash contribution (such as property, stocks, etc.) please contact the Fetal Hope Foundation at 1.877.789.HOPE (4673) for details.