Multiple pregnancy affects 0.9-3.1% of births worldwide. Prevalence rates vary significantly due to differences in dizygotic twinning rates and use of assisted reproduction (AR). Both maternal and fetal/neonatal complications are more common in multiple compared to singleton pregnancies and there are specific problems for the fetuses related to monochorionicity. Multiple pregnancies require specialized and individualized care. Complicated multiple pregnancies should be managed in a tertiary care centre where there is additional expertise, such as the laser ablation needed to treat monochorionic monozygotic pregnancies with conjoined circulations. Cornerstones of management in pregnancy are the need for accurate fetal measurement to optimise dating of gestational age, and documentation of chorionicity. High level ultrasound expertise is needed. The mothers need frequent assessment to detect hypertension and anemia, and early identification and management of preterm labor.
