Monochorionic twins account for about 10 - 20% of twin pregnancies. A monochorionic pregnancy occurs when a single fertilised ovum splits into identical twins after 3 days of ova fertilisation. This condition has an increased risk of perinatal morbidity and mortality compared to dichorionic twin pregnancies. The placenta in monochorionic twins contains several inter-fetal vascular anastomoses. The abnormality of a single placenta serving two twins can lead to: Twin to Twin Transfusion Syndrome (TTTS), Twin Anemia-Polycythemia Sequence (TAPS), selective intrauterine growth restriction or Twin Reversed Arterial Perfusion sequence (TRAP).
Last date updated on September, 2014