Observational epidemiological analyses demonstrated a decreased risk of death and severe morbidity associated with caesarean delivery at term but an increased risk at preterm gestational age. A multicentre international randomized controlled compared planned caesarean section with vaginal birth and observed no difference in outcome; however, the trial included preterm and term births in approximately similar proportions. A subsequent re-analysis of the trial demonstrated that planned caesarean section was associated with an increased risk of adverse neonatal outcome at preterm gestational ages, but reduced the risk of perinatal complications at term, consistent with the epidemiological studies. Hence, decision-making around mode of delivery for twins should recommend against routine caesarean delivery preterm. At term, the balance of risks and benefits will vary according to the mother's prioritization of avoiding intervention, her attitude to managing the risks of uncommon but potentially severe adverse events, and her plans and potential for future pregnancies.