A case of type III selective intrauterine growth restriction in a monochorionic twin pregnancy with a myriad of Doppler changes of the umbilical and vitelline arteries

Monochorionic twins have higher mortality rates than dichorionic twins. Selective intrauterine growth restriction (sIUGR) is a common complication found in monochorionic twins. We report such a case of type III sIUGR monochorionic twins. There was positive end-diastolic flow of umbilical arteries, which corresponded to type I sIUGR at 15 weeks. Then, the umbilical arteries showed persistently absent end-diastolic flow at 17 weeks which corresponded to type II sIUGR. Finally, the umbilical artery showed intermittent absent/reversed end-diastolic flow which corresponded to type III sIUGR. This case demonstrated a unique myriad of Doppler changes during the pregnancy, indicating its significance in being reported. The twins were delivered by caesarean section at 32 weeks and were developing well. Placental examination showed unequal placental sharing and the presence of an arterio-arterial anastomosis. These are characteristic findings of a type III sIUGR. Type III sIUGR may not be obvious at the initial examination but may only be obvious at later examinations.