Case-report: Spontanous TAPS detected antenatally in monochorionic twin pregnancy

Introduction: In monochorionic twin pregnancies there might be specific complications, which are due to the single placenta where vascular anastomoses are present. These anastomoses allow the transfer of blood from one fetus to the other and vice versa. They are the course for the development of twin-twin transfusion syndrome (TTTS) and twin anemia-polyzythemia sequence (TAPS). The risk of TTTS is approximately 9% in monochorionic twins. TAPS complicates approximately 3 – 5% of monochoriotic twin pregnancies, whereas the postlaser form occurs in 2 – 13%. Most cases of TAPS are detected after birth. There are only a few cases described which were detected during pregnancy, most of them after laser surgery. Antenatal criterias of TAPS are the abnormalities in Doppler ultrasound of the fetuses. The peak systolic velocity of the middle cerebral artery (MCA-PSV) shows an increase in the donor twin and a decrease in the recipient. The cutoff-levels are 1,5 multiples of median (MoM) for the donor and about 0,8 or 1,0 MoM for the acceptor.

In this paper we describe a spontaneous TAPS, detected during pregnancy, without any signs of TTTS (TOPS).