While investigating the use of progesterone for the relief of premenstrual syndrome (Greene and Dalton, 1953) a high incidence of toxaemia of pregnancy (19.1 %) was recognized among sufferers from this syndrome. A further investigation, undertaken to ascertain the incidence of premenstrual syndrome in those who had previously suffered from toxemia of pregnancy, revealed that 86% of the 237 women thus affected at one time or another during the previous twelve years also suffered from premenstrual syndrome (Dalton, 1954). Furthermore, direct questioning and a scrutiny of records of these patients showed that before the full development of the signs of toxaemia–that is, oedema, hypertension, and albuminuria–most had earlier in the pregnancy experienced a symptomatic stage characterized by relatively minor afflictions–for example, lethargy 43 %, headache 48%, visual aura 37%, vertigo 29%, nausea and vomiting 16%, irritability 14%, depression 9%, and backache 6%. In fact, only 7% disclosed freedom from these symptoms during a toxaemic pregnancy. Of the 237 women, 92 (38.8%) had experienced both a normal and a toxaemic pregnancy, and 72 (78 %) contrasted the sense of well-being associated with a normal pregnancy with the malaise and minor symptoms characteristic of the toxaemic condition.
The striking feature of these early minor symptoms of toxaemia was their close resemblance to those of premenstrual syndrome noted in an earlier investigation (Greene and Dalton, 1953), most patients confirming that the minor symptoms during their toxaemic pregnancy were similar, though of increased severity, to those experienced in the premenstruum, irrespective of whether the onset of premenstrual syndrome had preceded or followed the toxaemic pregnancy.
Apart from the similarities of these minor symptoms in the two conditions, other points in common were noted.
For example, day-to-day observations of sufferers of premenstrual syndrome had shown that, apart from minor symptoms, some developed oedema, hypertension, and albuminuria during the premenstruum, with spontaneous improvement during menstruation.
This appeared to be analogous to the spontaneous resolution of oedema, hypertension, and albuminuria following delivery. Furthermore, if symptoms remain untreated either in premenstrual syndrome or in toxaemia both diseases may culminate in fits, epileptic in the one case, eclamptic in the other.
In an earlier investigation one of the reasons for using progesterone in the treatment of premenstrual syndrome had been that some patients suffering from this condition were symptom-free during pregnancy. It was considered that the corpus luteum and placenta supplied enough progesterone during pregnancy to keep these patients symptom-free. Others were not only unrelieved of their premenstrual symptoms during pregnancy, but, as already indicated, developed symptoms closely resembling those of the premenstruum and culminating in toxaemia. It was therefore thought possible that the development of toxaemia might in such cases arise from failure of the corpus luteum and placenta to produce sufficient progesterone.
In the light of similarities between premenstrual syndrome and toxaemia, and the fact that treatment of the former with progesterone not only relieved the symptoms (Greene and Dalton, 1953) but also prevented the development of edema, hypertension, and albuminuria in the premenstruum (Dalton, 1954, 1955), it was decided to carry out a trial, employing large doses of progesterone in patients disclosing early minor symptoms of toxaemia, in an attempt to arrest full development of that condition.
00wrevg56