ad. 21. Monochorionic diamniotic twin pregnancy. Should the ultrasound examination be performed more frequently?
If a monochorionic diamniotic (with two babies’ “homes”) twin or multiple pregnancy (with one placenta) is confirmed, it is essential to undergo a more frequent ultrasound examination! Between 16 and 24 weeks, every two weeks, it is necessary to assess the volume of the amniotic fluid of both fetuses, in order to exclude complications connected with this type of twin pregnancy (twin-to-twin transfusion syndrome – TTTS, occurring in ab. 5-10% of cases). It is very important to diagnose an abnormality possibly quickly so there is sufficient time to employ an appropriate procedure.
Often (in ab. 30% of monochorionic diamniotic pregnancies) in the third trimester of pregnancy selective intrauterine growth restriction of one of the twins is observed. A regular monitoring of fetuses is necessary in such a case.