Does neonatal and infant neurodevelopmental morbidity of multiples and singletons differ?

The mortality and morbidity of twins may differ from that in singletons because of the greater incidence of intrauterine growth restriction, higher rates of prematurity, zygosity and even from the presence of a same age sibling during childhood. Early outcomes appear poorer for twins, but any differences are lost when corrections for gestation and growth restriction are made. Some studies show poorer cognitive outcomes for twins; larger and more recent studies show small but significant differences even when confounders are taken into account. Cerebral palsy rates are considerably higher in twins, especially with the death of a co-twin. Behavioural outcomes are broadly similar in twins and singletons, with growth and gestation being more important determinants than plurality. Psychiatric symptoms again are broadly similar, although there appears to be a reduced risk of suicide in twins.