Tundraco's Daily Living Guide to Health Twin-to-Twin Transfusion Syndrome

Twin-to-Twin Transfusion Syndrome (TTTS) is a disease in which blood is shared disproportionally by identical twins while in utero. It is also called Feto-Fetal Transfusion Syndrome. When this occurs, one fetus acts as the recipient of the transfusion, while the other is the donor. As a result of this imbalance, the donor fetus may suffer from anemia to the point of death. At the same time the recipient fetus's system is overloaded by too much blood, this can result in cardiac failure. With TTTS the transfusion occurs due to abnormalities in the placenta, in almost all cases the fetuses are themselves normal and healthy.

• TTTS can occur at any point during the pregnancy. If it begins near the onset of labor or during labor and delivery is classified as the Acute form of TTTS. If it presents itself during the second trimester, it is considered Chronic TTTS.

TTTS only occurs with identical monochorionic twins. TTTS can also afflict pregnancies in which three, or more, identical fetuses are present. Approximately 6000 cases of TTTS are diagnosed each year in the U.S., of which two-thirds of the cases result in the death of one or both twins. On average the chances of TTTS occurring with monochrionic twins is between 5-10%.

• Monochrionic twins are identical twins that share the same placenta but which have their own amniotic sacs.
• Why TTTS occurs is unknown and current research has been unable to pinpoint addition risk factors other than that it only occurs in identical twin pregnancies.
• TTTS can occur without warning and usually presents itself between the 16-26^th week of pregnancy. If left untreated, both twins may die.

• Serial (Therapeutic) Amniocentesis - one of the symptoms of TTTS is excesses amniotic fluid. The fluid levels are reduced by the insertion of a needle into the amniotic sac and removing excess fluid. This does not correct the underlying problem and several procedures may need to be performed to keep the fluid levels in check.
• Laser Photocoagulation - Laser surgery can be performed on the placenta to seal the vessels siphoning blood from the donor to the recipient fetus. This surgery is only performed on women who are less than 26 weeks pregnant. This treatment is new and the success rate has yet to be determined.
• Endoscopic Laser Surgery - this is another method of laser surgery to close the connecting blood vessels. This procedure is performed if the placenta is close to the mother's skin.
• Umbilical-cord Ligation - This is a last ditch procedure to save the healthier of the two fetus. In this case, the umbilical cord of the sick twin is tied off, resulting in death of the one twin, but has a success rate of 70-80% for the other twin.
• Selective Fetectomy - this involves surgically aborting one of the fetuses in order to give its twin a chance at survival.
• Septostomy - This procedure is done with a needle, by which a hole is created in the amniotic sacs to allow the fluid level to equalize. In TTTS the larger twin tends to produce excessive amounts of amniotic fluid whereas the donor twin's sac tends to suffer from a lack of fluid causing it to become stuck to its sac.

In many cases, TTTS results in the death of one or both fetus. Other affects can include the onset of premature labor, anemia in the donor fetus or heart failure for the recipient fetus. Cerebral palsy can also occur due to lack of oxygen near the time of birth.

TTTS can be hard to diagnose before problems present themselves. Ultrasounds can be helpful in identifying the condition because in cases of TTTS, the recipient twin tends to be much larger than the donor twin. Occasionally the connective vessels are visible with an ultrasound. Symptoms that TTTS is occurring can be manifested by,

• Polyhydramnios – the presence of excessive amount of amniotic fluid.
• Sudden weight gain in the mother, as well as sudden swelling due to the excessive fluid.
• Stomach feeling extremely tight or stretched out.
• Premature contractions and vaginal bleeding can also by symptoms of TTTS.
• Difficulty breathing.