Congenital Defects associated with Prematurity.

Children who are premature in the sense that their birth weight is not more than 5+ lb. (2 5 kg.) are generally believed to have more mental and physical defects than heavier children. It has, however, seldom been possible to compare the prevalence of defects ascertained in a standard manner in children who are premature and those who are not. Neither is the relative prevalence of specific defects known according to gestational age, nor according to factors associated with prematurity such as surgical induction of labour and multiple birth. In a prospective study of maternal health in early pregnancy in relation to congenital defects in 3,179 children, there was an opportunity to compare the defects found in 204 premature children with those found in 2,975 children who were not premature and, although the sample of premature children was very small for this purpose, to examine the effect of gestational age, surgical induction of labour and multiple birth. A questionnaire had been completed at the mothers' first antenatal attendance, which included personal particulars, a brief obstetrical and medical history and a detailed account of illnesses and events during the first 12 weeks of pregnancy. A report on the infants was obtained within a few weeks of birth and later when they were between 3 and 6 years old. Details of this survey and its results are published elsewhere (McDonald, 1958; 1961). A brief account only is given below of the methods used in measuring the gestation period and in ascertaining defects in the children at 3 to 6 years of age. At her first antenatal attendance the mother was carefully questioned about the date of her last menstrual period. When she was unable to give a date she was asked if possible to state a period of time within which it occurred. By this means it was possible to place all but three of the premature infants into two groups according to whether or not their stated period of gestation reached 36 weeks. Defects in the children were ascertained in the following way. Reports were obtained from health visitors on a standard form for five-sixths ot int children. Most of the rest had been clinically examined at school and for these the results of this examination were used; but in the case of a few children who had not yet had a school medical examination and for whom a health visitor's report was not obtained, reports were sought from mothers and general practitioners. The more serious defects. reported by health visitors were verified by reports from specialists. I examined personally children with suspected defects if a clinical report was not available or if they had any evidence of motor or mental retardation or deafness. Of the 204 premature infants, 32 were stillborn, 23 died neonatally and 149 survived the first fourweeks of life. One child died of leukaemia at 14 months. Reports were obtained on 142 of the 148 remaining children when they were between 3 and 6 years old. One of the six untraced children was known to have been adopted, two to have emigrated and three to have removed to an unknown address. Prevalence of Defects