Neurology and behaviour of growth-retarded neonates. Relation to biochemical placental function tests in late pregnancy.

Serial estimations of maternal urinary oestriol, serum cystine aminopeptidase (S-CAP), and human chorionic somatomammotrophin (S-HCS) were done in a prospective study on 29 pregnancies in which intrauterine growth retardation was diagnosed in the third trimester by the gravidogram method and/or serial ultrasound measurements of the fetal biparietal diameter. The series was divided into 2 growth-retarded groups: (i) severe growth retardation with birth weight less than -2 SD from the mean for gestational age (N = 14); (ii) moderate growth retardation with birth weight between -1 and -2 SD from the mean for gestational age (N = 15). These were compared with a control group of 18 normal pregnancies and infants. A modified Prechtl neurological examination and the Brazelton Neonatal Behavioural Assessment Scale (NBAS) were done in the neonatal period at full-term age. Both categories of growth-retarded infants showed lower muscle tonus than the controls. The severely growth-retarded infants showed fewer optimal items in the neurological examination; they also showed poorer capacity for orientation to external stimuli, inferior motor function, and less physiological stability in NBAS than the controls. The abnormal biochemical placental tests were significantly correlated to low Apgar scores (urinary oestriol), to low excitability (S-CAP) and to poor motor function (S-HCS). The neurological and behavioural condition of the neonate seemed to be more closely associated to the extent of growth retardation than to the occurrence of abnormal biochemical placental tests.