Placental magnetic resonance imaging in monochorionic twin pregnancies

Twin-twin transfusion syndrome (TTTS) is a severe complication of monochorionic pregnancies. Placental hydrops might be a marker for TTTS. The purpose of this study was to evaluate whether differences in the placental parenchyma due to TTTS can be seen with fetal MRI.

In a retrospective study, 34 monochorionic pregnancies were investigated on a 1.5 Tesla MR. Seventeen pregnancies were affected by TTTS, and 17 showed no clinical signs of TTTS. Placental maturation and vascular pathologies, as well as the extent of the placental findings and allocation of placental tissue to each twin, were investigated. Placental findings were reported for origin, size, maturation, and placental thickness, and were correlated with the presence of TTTS.

All placentas affected by TTTS showed abnormal maturation on MR scans, but only 64.7% of the non-TTTS group (p = 0.018). Vascular placental pathologies did not differ significantly between the TTTS and non-TTTS group.

MR-signs of placental maturity in monochorionic twin pregnancies may indicate a lower risk of development of TTTS.