Mackie FL, et al. - Researchers aimed at assessing the ability of first trimester pregnancy related factors (ultrasound measurements, maternal characteristics, biomarkers) in determining the complications in monochorionic twin pregnancies. They searched MEDLINE, EMBASE, ISI Web of Science, CINAHL, the Cochrane Central Registration of Controlled Trials and Research Registers, and Google Scholar, from inception to 12 May 2017 for studies that reported ultrasound measurements, maternal characteristics, or potential biomarkers, measured in the first trimester in monochorionic diamniotic twin pregnancies, where the potential prognostic ability between the variable and twin-twin transfusion syndrome, growth restriction, or intrauterine fetal death could be assessed. As per outcomes, it is not currently possible to predict adverse outcomes in monochorionic twin pregnancies.