Purpose of review: Selective intrauterine growth restriction (sIUGR) in twin pregnancies presents a complex management problem for the fetal medicine specialist. This review summarizes what is currently known about sIUGR pathophysiology, particularly in monochorionic pregnancies and looks at the results of early trials of fetal intervention in high-risk sIUGR pregnancies.
Recent findings: sIUGR in monochorionic pregnancies is due to unequal placental sharing, but the clinical outcome is determined by the characteristics of the placental vascular anastomoses. Classification of monochorionic sIUGR by umbilical artery Doppler allows interventions to be targeted at high-risk subgroups. The overall survival after diagnosis of early-onset Type II/III sIUGR is similar after the management with cord occlusion and selective laser photocoagulation of connecting vessels.
Summary: Fetal interventions have been shown to be feasible and of potential benefit in early-onset sIUGR in a monochorionic twin pregnancy. Cord occlusion or selective laser photocoagulation of connecting vessels may be offered as an alternative to expectant management or preterm delivery in early-onset severe cases after careful discussion with the parents. Randomized controlled trial evidence is required to make a definitive judgment and to determine the impact of fetal intervention on the neurological outcomes.