Clinical outcome and placental territory ratio of monochorionic twin pregnancies and selective intrauterine growth restriction with different types of umbilical artery Doppler.

OBJECTIVE

To evaluate the clinical outcome and placental territory ratio in monochorionic diamniotic (MCDA) twin pregnancies and selective intrauterine growth restrictions (sIUGR) with different types of umbilical artery (UA) Doppler.

STUDY

DESIGN

An MCDA twin pregnancy with sIUGR was defined as a fetal weight below the 10th percentile in one twin. MCDA twins were divided into three groups: without IUGR (group I); with sIUGR, and a normal UA Doppler (group II); or an abnormal UA Doppler (persistent absence or reverse of end-diastolic velocity) (group III). Placental territory was calculated as the estimated individual placental mass/total placenta weight.

RESULTS

Altogether, 27 cases of group I, 11 cases of group II and 13 cases of group III MCDA twins were included. The placenta territory of the IUGR twin in group III MCDA twin was the smallest among the three groups of MCDA twins (ANOVA test, p < 0.001). There was incidence of neonatal death in six (6/26) of group III MCDA fetuses, while none in groups I and II MCDA twins did.

CONCLUSIONS

In MCDA twins with sIUGR, abnormal UA Doppler in the IUGR twin may reflect a more severe unequal placenta share and poorer neonatal outcomes. The prognosis of group II MCDA twins, even with sIUGR found in early gestation, is, by contrast, better.