Multiple births are important contributors to the preterm and low birthweight population and the numbers of twin births have been steadily rising since the early 1980s in all developed countries. This is largely due to the increased use of ovulation induction and multi-embryo transfer in the treatment of subfertility. Parents of preterm twins have been shown to be less responsive to their infants than those with singletons. Parental stress with twins has also been demonstrated by the higher incidence of maternal depression and of child abuse in multiple birth families. Furthermore, siblings of twins are more likely to have behaviour problems. Mortality and long-term morbidity rates are greatly increased amongst multiple birth children. The problems of the single surviving twin and the unaffected co-twin of a disabled child are often underestimated as is the complexity of the bereavement of parents who still have surviving multiples. Addressing the cause of the epidemic of iatrogenic multiple births is likely to be the single most effective way to reduce the number of preterm infants and the long-term problems to which they are prone.