Recent research concerning the contribution of intrauterine factors to mental retardation has centered on two areas.The first area is fetal alcohol syndrome. Underdiagnosis has been suspected for some time largely because of the failure of paediatricians to always recognise the subtle dysmorphism. More accurate recogniton of this has been facilitated by research in the past 12 months which should enhance the recognition and diagnosis and reduce the number and percentage of remaining undiagnosed cases of mental retardation. The second area is cerebral palsy. It is well known that cerebral palsy is frequently accompanied by learning difficulties and the same insult which causes the motor deficit in cerebral palsy is also responsible for the learning difficulty. Recent research, particularly in the past 12 months, has recognised that up to 40% of term and 20% of preterm babies have prepart origin for their cerebral palsy and this represents another significant contribution of previously unrecognised intrauterine events to the causation of mental retardation.