Intertwin discordance of aldosterone levels in amniotic fluid with placental anastomoses in monochorionic twins: Insight into the pathophysiology of twin-to-twin transfusion syndrome.

The AF-ALD levels reflect the UCB-ALD levels in MD twins. The presence of placental anastomoses led to intertwin discordance in the ALD levels in MD twins even uncomplicated with TTTS. It was considered that monochorionic twins have this clinical background, and it leads to the development of TTTS.