Assessment of fetal growth in twin pregnancies: evidence‐based practice

Key content Twin pregnancies are at an increased risk of fetal growth restriction and require tailored growth surveillance strategies. Fetal growth in twin pregnancies is strongly influenced by chorionicity. In dichorionic twins, fetal growth restriction typically arises from uteroplacental insufficiency affecting one or both fetuses. In monochorionic twins, unequal sharing of the single placenta with its intertwin vascular anastomoses is the key determinant of fetal growth. Intertwin discordance and selective fetal growth restriction are key concepts in twin growth assessment. Singletons and twins follow different growth trajectories; hence, using singleton growth standards for twin growth surveillance may overestimate growth restriction in twins, leading to unnecessary interventions. Twin‐specific growth charts have the potential to improve diagnostic accuracy and clinical decision‐making in antenatal care of twin pregnancies. Learning objectives To understand the physiological differences in fetal growth between twin and singleton pregnancies. To evaluate the role of twin‐specific growth charts and emerging evidence surrounding their use in clinical practice. To review the current key recommendations in the antenatal growth surveillance of twin pregnancies. Ethical issues Potential overtreatment of healthy twins due to misclassification using singleton charts.