[The influence of moderate intrauterine nutrition on later physical and mental development in twins (author's transl)].

Follow-up examinations on 45 dizygotic and monozygotic twins were performed in order to establish differences in physical and mental development with regard to differences in birth-weight. The "critical" weight difference of at least 650 g could be established where mental abilities, height and head circumference scored lower in the lower birth weight group. Our findings stress the positive home environment as being responsible for the lack of differences between the two groups in the development during early childhood, of psychosocial behaviour and school performance.