Prematurity and paid work during pregnancy.

Most enquiries into the causes of prematurity conclude that at least 50 per cent. of cases cannot be explained on medical grounds (Joint Committee of the Royal College of Obstetricians and Gynaecologists and the British Paediatric Association, 1949; Baird, 1953). In these cases pregnancy is clinically normal but nevertheless labour starts before the expected date, or, if the baby is born at term, it weighs 5k lb. or less. In such circumstances poor maternal health and physique, inadequate diet, and overwork or worry may be involved. These influences are difficult to measure, and since several may operate together the effect of each cannot be easily disentangled. For example, hard physical work might have no ill effect on a healthy well-fed woman but might bring on premature labour in one who is under-nourished or unhealthy. Again it seems possible that paid work accompanied by heavy domestic responsibilities or anxieties over money or housing might cause more harm than the same amount ofwork done under happier conditions. Light work in an office, shop, or factory may not involve as much strain as housework and, if there is little domestic responsibility, may be more a relaxation than a task. Various investigators have shown, however, that the prematurity rate increases with the length of time worked during pregnancy (Royal College of Obstetricians and Gynaecologists, 1948; Douglas, 1950; Ferguson and Logan, 1953). Our preliminary investigations pointed in the same direction. Table I shows that in Aberdeen in each social class married