Obstetric Complications as Risk Factors for Cerebral Palsy or Seizure Disorders

Abstract

Complications of pregnancy and birth are more frequent in the medical histories of children with cerebral palsy than in the histories of neurologically normal children. Articles dealing with the etiology of cerebral palsy and other developmental disorders have stressed the importance of asphyxia, which is assumed to account for much of the chronic neurological morbidity dating from early life.

Some obstetrical problems thought to be associated with asphyxia are also associated with an increased incidence of low birth weight. Although birth weight, oxygen deprivation, and complications of pregnancy and delivery are discussed frequently in the literature on cerebral palsy and on epilepsy, there are few studies that examine the interrelationship of these factors with long-term outcome in surviving children.

The present authors, in a large prospective study, investigated the magnitude of risk of cerebral palsy or seizure disorders associated with “potentially anoxogenic” complications of pregnancy. They considered whether, in the presence of complications, low Apgar score was a useful indicator of the risk of poor neurological outcome. They also investigated the proportion of cerebral palsy and of nonfebrile seizure disorders derived from pregnancies complicated by these obstetrical conditions, with and without low Apgar score.

Of 51,285 live births in this sample, outcome at 7 years of age was known for 45,559. One hundred and eighty-nine children had cerebral palsy, and 323 children had nonfebrile seizures and no cerebral palsy. There were 1276 deaths before the first birthday, most of them in the neonatal period.

Late obstetrical complications were common, one or more being present in 62 per cent of the pregnancies studied (Table 1). Some of the conditions studied, notably placental complications (previa and abruption), abnormalities of presentation (face, brow, and transverse), breech delivery, and prolapse of the umbilical cord, were associated with high rates of birth weight lower than 2500 gm (group A, Table 1; factors are listed within groups in descending order of association with low birth weight). These same conditions were the complications most frequently related to depressed 5-minute Apgar scores.

Birth weight was a dominant factor in mortality. Within the low birth weight group, the complications associated with low Apgar scores were associated with high infant mortality. In infants over 2500 gm with complicated births, low Apgar scores and infant mortality were much less frequent, but were also correlated.