Austrian Registry on the Outcome of Monochorionic Pregnancies

Austrian Registry on the Outcome of Monochorionic Multiple Pregnancies: A Multicenter Registry Study

About one third of twin pregnancies are resulting from a single fertilized oocyte. Two third of these monozygotic twins share a common placenta and are therefore called monochorionic. Due to placental sharing and the ever-present inter-fetal vascular connections, specific complications may arise and lead to an increased risk of intrauterine death and long-term neurodevelopmental impairment. Specific complications include twin-to-twin transfusion syndrome (TTTS), twin-anemia-polycythemia sequence (TAPS), selective intrauterine growth restriction (sIUGR) and discordant major anomalies, occurring in about 10%, 5%, 20% and 6% of monochorionic diamniotic twins. Prenatal interventions may improve perinatal and long-term outcome of affected fetuses. However, general knowledge about early diagnosis of monochorionic twins and their specific complications is still limited in a significant number of practitioners in Austria and systematic analysis of pregnancy outcomes are not conducted.

In this prospective multicenter registry study, the investigators aim to include all monochorionic pregnancies in Austria. Main outcome parameter is the occurrence of complications. Secondary outcomes are gestational age at occurrence of complications, gestational age delivery and neonatal outcome. The investigators also strive for long-term outcome, especially of infants following complicated pregnancies or preterm birth.

Inclusion Criteria:

• All monochorionic pregnancies diagnosed from 11+0 weeks of gestation

Exclusion Criteria:

• Dichorionic twin pregnancies or higher-grade multiples without a monochorionic pair