World TTTS Awareness Day Date in the current year: December 7, 2024

Twin-to-twin transfusion syndrome (TTTS), also known as stuck twin syndrome, twin oligohydramnios-polyhydramnios sequence (TOPS) or feto-fetal transfusion syndrome (FFTS), is an identical twin pregnancy complication characterized by disproportionate blood supply between the fetuses. If left untreated, TTTS usually results in the death of one fetus and an increased risk of developmental defects for a surviving fetus.

There are several forms of TTTS: twin anemia polycythemia sequence (TAPS), selective intrauterine growth restriction (SIUGR), and twin reversed arterial perfusion sequence (TRAP sequence, TRAPS). TAPS is different from classic TTTS in that it involves an unequal sharing of red blood cell counts between the fetuses without an amniotic fluid difference. Since mothers with TAPS experience little to no symptoms, this form of TTTS is known as the silent killer.

SIUGR (or sIUGR) is the form of TTTS where one of the fetuses is small for its gestational age due to unequal sharing of the placenta between the fetuses. Finally, TRAP is a severe form of TTTS where the blood systems of the twins are connected and one fetus’s heart is severely deformed or missing. As a result, the other twin has to pump his or her heart for both fetuses and will not survive in 50–75% of cases is TRAP is left untreated.

World TTTS Day was launched by The Twin to Twin Transfusion Syndrome Foundation, an organization that provides emotional, educational and financial support to families affected by TTTS. It was founded by Mary Slaman, who was diagnosed with TTTS syndrome in 1989, 18 weeks into her pregnancy. Her doctors told her there was no cure even though they knew of cutting-edge laser surgery that could have been done on her placenta.

Due to lack of treatment, one of Slaman’s twins, Steven, died at 26 weeks. The other one, Matthew, was born at 36 weeks and survived without any long-term complications. After delivering both of her babies on December 7, 1989, Slaman held them in her arms and promised them that they would be known and remembered. And she lived up to her promise by founding The TTTS Foundation and designating December 7 as World TTTS Day.

Slaman also coined the term “daisy babies” for babies that have gone through TTTS. She compared TTTS to a tornado because you never know when it is going to hit, and the TTTS foundation is fighting for the day after the storm, when all babies affected by the syndrome will survive and thrive like daisies flourishing in the field.

In addition to World TTTS Day, the TTTS Foundation also organizes World TAPS Day (December 8), World SIUGR Day (December 9), and World TRAP Day (December 10) to raise awareness of each form of TTTS. The entire month of December has been designated as TTTS Awareness Day.