A dramatic increase in the incidence of multiple pregnancy and delivery has occurred during the past decades, primarily due to a higher childbearing age and the wide availability of assisted reproductive technologies (ART) and non-ART procedures such as intrauterine insemination and ovulation-inducing drugs. Multiple pregnancy (especially twin pregnancy) has been regarded as an almost inevitable but acceptable complication of ART, and many patients consider twins to be a desirable outcome of these procedures. Proponents of this view ignore the serious consequences of multiple pregnancies for the couple, the newborns and the society1.