This is an observational study in 3 cohorts of monochorionic diamniotic (MCDA) twins. The aim of the study is to assess whether unequal placental sharing can be predicted in pregnancy and whether it is predictive of pregnancy outcome.
MCDA cohort
Ongoing monochorionic diamniotic twin pregnancy between 11 and 14 weeks, as determined by the crown rump length of the larger twin in spontaneous conceptions and by the date of insemination or embryonic age at replacement in pregnancies resulting from subfertility treatment
Women aged 18 years or more, who are able to consent
Written informed consent to participate in this study, forms being approved by the Ethical Committees
Age < 18 years
Inability to consent