D. A. Davey

The classification and definition of the hypertensive disorders of pregnancy

Hypertension and proteinuria in pregnancy may be the result of a number of different disorders with different etiologies and pathologic characteristics. As the causes of hypertension and proteinuria in pregnancy are largely unknown, a new clinical classification of the hypertensive disorders is proposed and is based solely on the physical signs of hypertension and proteinuria. The classification is intended to define meaningful clinical categories by which all cases of hypertension and proteinuria occurring in pregnancy, labor, or the puerperium may be classified. New definitions of hypertension and proteinuria are also proposed; they are based on standardized methods of measurement and simple criteria of abnormality. It is hoped that this clinical classification and associated definitions will find general acceptance so that the incidence and outcome of the hypertensive disorders of pregnancy and the results of research in different centers may be compared and mutual understanding achieved.

Placental bed spiral arteries in the hypertensive disorders of pregnancy

Objective— The investigation of the histology of the placental bed spiral arteries in normal pregnancy and in pregnancies complicated by hypertension, with or without proteinura.

The effect of sublingual nifedipine on uteroplacental blood flow in hypertensive pregnancy

Summary. The effect of nifedipine on uteroplacental blood flow was investigated in nine hypertensive women in the third trimester of pregnancy and compared with the effects of a placebo in nine similar hypertensive women. An index of uteroplacental blood flow was obtained, twice before treatment and once after treatment, by measuring the increase in radioactivity in the region of the placenta with a gamma camera following an intravenous injection of indium‐113m. There was no significant change in the blood flow index in either the nifedipine‐ or the placebo‐treated groups despite a significant fall in blood pressure with nifedipine. Nifedipine lowers the blood pressure without any apparent reduction in uteroplacental blood flow.

Haemodynamic changes in gestational proteinuric hypertension: the effects of rapid volume expansion and vasodilator therapy

Dear Sir, We read with interest the article by Belfort et al. [BrJ Obstet Gynaecol(l989) 96,634-6411 on the haemodynamic changes that accompany volume expansion in pre-eclampsia, and the accompanying editorial by Duncan (1989). Belfort el al. conclude that volume expansion may be of therapeutic benefit in the severely hypertensive patient with a low cardiac index. Similarly the accompanying editorial states that ‘the notion of pharmacological vasodilatation of the arterial circulation and volume expansion is an appealing one, seeming to counter the effects if not the cause of the condition’. Low plasma volumes and raised blood viscosity are consistently found in women with severe pre-eclampsia, and these changes may exert an unfavourable effect on placental perfusion. There may be no causal link but endogenous levels of aldosterone, the salt-retaining steroid, are also relatively low in this disease compared with normal pregnancy. For the last 9 months we have administered fludrocortisone, the synthetic mineralocorticoid, to selected patients with severe early pregnancy-induced hypertension, and several interesting observations have been made. The treatment appears to reduce peripheral oedema whilst raising plasma volume (in one case by 34%) with corresponding reductions in blood viscosity and haematocrit. It is possible that the effects are not mediated purely through renal handling of sodium but that there is a direct effect on vascular permeability to sodium and water which could be relevant to the prevention of eclampsia (where cerebral oedema is a prominent feature). When the optimum dose of fludrocortisone has been established, a placebo-controlled trial of this therapy is planned to determine whether this approach will be of any clinical benefit. N. G. Saunders R. B. Fraser Department of Obstetrics and Gynaecology University of Shefield Clinical Sciences Centre Northern General Hospital Herries Road Sheffield S.5 7AU

The variability of urinary protein and creatinine excretion in patients with gestational proteinuric hypertension

Objective To determine the variability of protein excretion in patients with proteinuric hypertension and the accuracy of either a urinary protein/creatinine ratio or a Multistix examination for the estimation of a 24 h protein excretion.

Neurofibromatosis and severe hypertension in pregnancy

Summary. Four pregnant patients with neurofibromatosis (Von Recklinghausens disease) either developed hypertension during pregnancy or had an exacerbation of a pre‐existing chronic hypertension. Two patients required early termination of pregnancy for severe hypertension; a third had severe intrauterine growth retardation resulting in intrauterine fetal death; and one had an otherwise uneventful pregnancy and a live healthy infant. Because of the association between neurofibromatosis and hypertension, patients with neurofibromatosis require special antenatal care and management.

The distribution of fibronectin in the placental bed in normotensive and hypertensive human pregnancies

Summary Endovascular trophoblast invasion into the spiral arteries of the placental bed is restricted to the decidual segments in pregnancy-associated hypertension (pre-eclampsia). Little is known about mechanisms that control trophoblast invasion. Extracellular matrix proteins such as fibronectin could be involved, as they are in other invasive processes. The observation of increased plasma fibronectin levels in patients that will develop pre-eclampsia (Ballegeer et al., 1989) prompted us to study the distribution of this glycoprotein in the placental bed of normotensive and hypertensive pregnant patients. Paraffin embedded sections were stained for fibronectin using the indirect peroxidase labeled antibody technique. Spiral arteries undergoing physiological changes stained virtually negative. In vessels with subintimal thickening an occasional fibronectin positive lining of endothelium and positive areas in the fibrous subintimal cushions could be found. The most intensive staining for fibronectin however was found in the arteries with acute atherosis, i.e., the vascular lesion that is thought to be associated with pre-eclampsia.

Osteoporosis, osteopenia and fracture risk: Widening the therapeutic horizons

The majority of women with fragility fractures have osteopenia rather than osteoporosis. In post hoc analyses of trials of alendronate and strontium ranelate, women with osteopenia had significant reductions in the incidence of fragility fractures and specific therapies may be mandated in women with osteopenia, as well as those with osteoporosis. Increasing numbers of fractures of the spine and hip occur in very elderly women and men over the age of 80, but in this age group it is often considered too late in life to start long-term specific therapies. In clinical trials of very elderly women, risendronate significantly reduced vertebral fractures and strontium ranelate significantly reduced vertebral, non-vertebral and symptomatic clinical fractures within 1 year of starting treatment. The indications for specific therapies for osteopenia and osteoporosis, as well as other measures for the prevention and treatment of fragility fractures, urgently need to be increased and widened.

THE INFLUENCE OF FETAL SEX UPON LIQUOR CYTOLOGY AS A MEANS OF ESTlMATING GESTATIONAL AGE

Prenatal sex determination after 30 weeks of pregnancy can be achieved simply and with a high degree of accuracy using the cyanophilic cell count on amniotic fluid. Differential cell counts as a means of estimating gestational age may be incorrect because of the sexual difference.

A COMPARATIVE CLINICAL EVALUATION OF THE FOAM TEST AND PHOSPHOLIPID ASSAY OF AMNIOTIC FLUID

Amniotic fluid taken by amniocentesis from patients at varying stages of gestation was analyzed for surfactant by the foam test, total phospholipid phosphorus concentration, and alkali labile phospholipid phosphorus concentration. The total and alkali labile phospholipid concentrations increased, and the ratio of alkali labile to total phospholipid concentration fell slightly as gestational age increased. The mean total and alkali labile phospholipid phosphorus concentrations increased with the foam test score, but there was considerable overlap in the phospholipid concentrations between the different groups of foam test results. In our experience only when the foam test is negative does hyaline membrane disease occur, and even then not invariably. Only when the foam test is negative, therefore, is further analysis of amniotic fluid for surfactant indicated. The simplest procedure is then to measure the amniotic fluid total phospholipid concentration. This will resolve the doubt as to whether the newborn is liable to hyaline membrane disease in about one half of the cases. The suggestions by other workers that the ratio between alkali labile phospholipid and total phospholipid would resolve this doubt has not been confirmed by our study.