Welcome at the TAPS registry website.  TAPSregistry is an international collaboration of maternal and fetal medicine centers round the world. The aim of this collaboration is to gain knowledge on twin anemia-polycythemia sequence (TAPS) in order to improve treatment options for this relatively new monochorionic twin pregnancy conditions.

For a concise description of TAPS see the short summary below or for more in depth information browse through the tabs on the right.

Summary on TAPS

TAPS detail webTwin anemia-polycythemia sequence (TAPS) is a novel form of chronic feto-fetal transfusion, characterized by large inter-twin hemoglobin differences, without signs of twin oligo-polyhydramnios sequence (TOPS).

The pathogenesis of TAPS is based on the presence of few, minuscule anastomoses at the placental surface (diameter <1mm) allowing a slow transfusion of blood from the donor to the recipient and leading gradually to highly discordant Hb levels.

TAPS may occur spontaneously or after laser surgery for TTTS (post-laser form). Spontaneous TAPS complicates approximately 1 to 5% of monochorionic twin pregnancies, whereas the post-laser TAPS occurs in 1 to 16% of TTTS cases treated with laser.


The optimal management in TAPS is not clear, and includes expectant management, induction of labor, intrauterine blood transfusion (intravenous and/or intraperitoneal, with or without partial exchange transfusion), selective feticide or fetoscopic laser surgery.

The outcome in TAPS is not well known. International cooperation between fetal centers using a web-based TAPS registry is needed to improve our knowledge on the on the short- and long-term outcome in TAPS cases and determine the optimal management.