Pre-Eclampsia in the Light of Current Research*

Research work in the United States and elsewhere on diabetes in pregnancy has already given some indication as to what form the future treatment of pre-eclampsia may take. It is the aim of this article to correlate the results of these researches with contemporary views on the aetiology of pre-eclampsia and other allied conditions encountered in pregnancy. It is necessary to mention only some of the salient features of diabetes in pregnancy. For as much as five years prior to the development of frank diabetes there is a prediabetic phase during which the birth weights of infants is greater than normal and the foetal mortality is raised (Allen, I939). When frank diabetes appears these become more pronounced and there is a fairly constant picture of hydramnios, large babies and high foetal and neonatal death rates in untreated cases. The explanation offered for these are mechanical difficulties due to the ' giant' baby and to the age of the mother, but there are other causes which are imperfectly understood. Toxaemia, which is frequently associated with the diabetes, is apparently an important factor (Barns and Morgans, 1948, 1949). These writers point out that the remarkable variation in estimates given by different observers of the increased liability to toxaemia in diabetes (which range from three to fifty times normal) depends chiefly on the severity of the standard' chosen for toxaemia. No doubt there are other factors, but it would appear that foetal hypoglycaemia, at one time thought to be an important, cause of neonatal death, is not in fact a common one (Sisson, 1940; Barns and Morgans, 1948, '949). Smith and Smith (1938, 1940, I948) have demonstrated that in these cases there is a profound hormonal imbalance, chiefly in the form of low oestrogens and progesterone levels in the blood. They describe a reciprocal relationship between the vascular supply of the placenta and the circulating level of steroid hormones, adequate vascularity being essential for the normal pro-