C. A. Michael

Intravenous Labetalol and Intravenous Diazoxide in Severe Hypertension Complicating Pregnancy

Summary: The results of a prospective trial to evaluate the use of diazoxide and labetalol given intravenously in the management of severe hypertensive disease in pregnancy are presented.

Serum Uric Acid as a Marker of Pregnancy-Induced Hypertension

Summary: A prospective longitudinal study was conducted, looking at the changes in serum uric acid during pregnancy in women who were normotensive at initial presentation. In our sample of 78 women having a total of 88 singleton pregnancies, 13 developed pregnancy‐induced hypertension during labour only, whilst a further 6 developed hypertension during pregnancy. Women who developed hypertension had significantly higher uric acid levels than women who remained normotensive throughout. However, there was an appreciable overlap between the groups. Women with essential hypertension showed similar changes. We conclude that the serum uric acid level is an unreliable indicator of developing hypertension in the individual woman. However, a rapidly rising uric acid level should be viewed with caution.

ACTOMYOSIN CONTENT OF THE HUMAN PLACENTA

The total soluble protein and the concentration of the contractile protein actomyosin were estimated in the human placenta at varying stages of gestation. As maturity and differentiation of the placenta occurred the proteins increased in concentration. The actomyosin was thought to be present in the smooth muscle fibres in the chorionic plate, and related to the placental vessel walls. The contractile property of the smooth muscle and the demonstration of contractile protein suggested that they play an active role in the dynamics of placental circulation.

Intravenous Diazoxide in the Treatment of Severe Pre‐Eclamptic Toxaemia and Eclampsia

Summary: Forty‐nine patients with severe pre‐eclampsia and 4 patients with eclampsia were treated with the hypotensive drug diazoxide combined with diaze‐pam. In all patients a satisfactory reduction and subsequent control of the blood pressure occurred. There was no maternal mortality and the perinatal mortality was 13%. After administration of the above drugs no eclamptic convulsion occurred or recurred. It is felt that the combination of diazoxide with diazepam is more effective in controlling an elevated blood pressure in labour than the previous conventional administration of heavy sedatives with their associated maternal and fetal hazards.

The Control of Hypertension in Labour

Summary: Twenty‐five patients with severe pre‐eclamptic toxaemia in labour were treated with one of the hypotensive drugs bethanidine or diazoxide combined with diazepam. In all patients a satisfactory reduction and subsequent control of the blood pressure occurred. There was no maternal mortality or morbidity and there was one neonatal death from prematurity. Diazoxide has a more rapid and predictable action than bethanidine, but it may cause hyperglycaemia in the fetus and therefore should probably be avoided in diabetic patients.

The Use of Bethanidine in Severe Hypertension in Pregnancy

Seventy‐six patients with severe hypertensive disease of pregnancy were treated with oral bethanidine. Control of the blood pressure resulted in prolongation of the pregnancy. The perinatal mortality was 9.2%. It is emphasised that adequate treatment with a hypotensive agent provides protection to the mother from the dangers and sequelae of hypertensive disease of pregnancy.

Treatment of Hypertension Arising in Pregnancy

To the obstetrician a raised blood pressure at any stage of pregnancy has serious implications. If the blood pressure is elevated in early pregnancy, complications are more likely to occur to both mother and fetus and the outcome may not be favourable. In labour, the threat of severe pre-eclampsia or eclampsia is a constant hazard. This article will not discuss the treatment of essential hypertension in a woman who becomes pregnant.

Response of Myometrial Autografts in the Rabbit Ear chamber to Oxytocin during Pregnancy

1 The changing sensitivity of myometrial autografts within rabbit earchambers to intravenous injections of oxytocin throughout the course of 6 normal pregnancies has been studied in a group of 5 female rabbits. 2 The myometrial autografts were shown to be sensitive to oxytocin from the 7th day of pregnancy. 3 The progressive reduction in the dosage of oxytocin necessary to produce myometrial contractions in the autografts has been shown to conform to a log hyperbolic curve. 4 The rather precise mathematical form relating minimum effective dose of oxytocin to day of pregnancy, obtained from these experiments, indicates that this preparation is of great potential value for the elucidation of the exact pattern of control of myometrial sensitivity throughout pregnancy. 5 The myometrial autografts increased very considerably in size during the progress of pregnancy and showed a rapid reduction in size post partum. 6 Associated with pregnancy, from as early as the 5th‐6th day, the vessels of the microcirculation, both in the grafts and in the earchamber fibrous tissue, developed very rapid pulsatile flow.

The concentration of actomyosin and soluble protein in uterine muscle.

The actomyosin and total salt soluble protein content were estimated in myometrium taken from non‐pregnant uteri. Both were reduced following the menopause and the difference in concentration was related to ovarian function. Age and parity of the patients were influencing factors. The cervix contained less actomyosin than the uterine body.

Type 1 Hyperlipoproteinaemia and Pregnancy

Whilst hyperlipoproteinaemia is a physiological accompaniment of normal pregnancy (Potter and Nestel, 1979), in patients with inherited disorders marked by hypertriglyceridaemia, the increase in plasma triglycerides in pregnancy may precipitate medical sequelae, placing the pregnancy and the patient at risk. The number of case reports concerning such patients are few (Glueck et al., 1980) and there is little information to guide the obstetrician and physician as to likely complications. The majority of cases which are reported concern the identification of women who present with complications such as pancreatitis during pregnancy and are subsequently found to have hypertriglyceridaemia (Millen et al., 1956; Adlersberg et al., 1959).