Developmental and neurological sequelae of the common complications of pregnancy and birth.

IT is important to understand the influence of obstetric complications on the neurological development of the infant and young child since the future planning of preventive and social paediatric services will depend largely on the clarification of this issue. Since Little (1861) wrote about the influence of abnormal parturition, difficult labour, premature birth and asphyxia neonatorum on the mental and physical condition of the child, a continuing interest has been maintained by clinicians and research workers in this field of work. However, numerous hypotheses supported by numerous statistically significant relationships have failed to effect a medically significant general advance in this sphere, with a few notable exceptions such as oxygeninduced retrolental fibroplasia, anoxic damage to the cochlear nucleus and rubella embryopathy. Two main areas of difficulty are (1) that a study of the relationship between the obstetric environment and neuro-psychiatric morbidity in childhood remains a no-man's-land bordered by the specialities of paediatrics, obstetrics, pathology, neurophysiology, epidemiology and psychology, and (2) the rigorous demands ofthe epidemiological method over the last 10 to 20 years have substantially diluted, and in many cases nullified, the findings of a great many clinical studies in this field of work. There is no doubt that obstetric complications carry an increased mortality'risk (De Haas-Posthuma, 1962; Butler and Bonham, 1963)-death of the fetus within a given time satisfies the epidemiological criteria of definition, but morbidity studies (which assess the damage to the surviving infant) are open to criticism unless strict definitions are available. A well-planned series of retrospective studies on seven neuro-psychiatric disorders began in 1943 under the guidance of Knobloch and Pasamanick (1962) in Baltimore. The prenatal experiences of 4,000 children presenting with the certain defined neuro-psychiatric disabilities were compared with those of matched controls, and statistically significant relationships were found between obstetric abnormalities on the one hand and 'minimal cerebral damage', cerebral palsy, epilepsy, mental deficiency and reading disabilities on the other. These findings led to the proposal of the hypothesis of 'a continuum of reproductive casualty', which was further tested by a prospective investigation of 500 premature infants. Although Knobloch and Pasamanick (1962) have also emphasized the importance of socio-economic influences, there is no doubt that the findings of their Baltimore study have significantly influenced contemporary medical thought with respect to the clinical aetiology of the neuropsychiatric disorders.