Randomised controlled comparative stufdy of methyldopa

One hundred pregnant women with hypertension (defined as diastolic blood pressure at or above 95 mm Hg) were allocated at random to treatment with methyldopa or oxprenolol and were compared with nonhypertensive controls matched according to parity and gestation at delivery. The patients were also stratified into those entering the study early (before 32 weeks' gestation) and those entering late (after 32 weeks' gestation). Although there were no differences in diastolic blood pressure between the hypertensive groups before or during treatment, in the early entry group the systolic blood pressure at entry of those allocated to oxprenolol was significantly higher than that of those receiving methyldopa; this difference remained throughout the treatment period. Also in the early entry group further increments of drug treatment were required to control blood pressure of patients receiving oxprenolol than in those receiving methyldopa. The eventual fetal outcome for all patients treated with methyldopa was the same as that for those treated with oxprenolol; birth weight, placental weight, head circumference, and Apgar score were not significantly different and there were no stillbirths in either group. Institute ofObstetrics and Gynaecology, Queen Charlotte's Maternity Hospital, London W6 OXG JACK FIDLER, FRACP, MRCOG, honorary lecturer VALERIE SMITH, SRN, MTD, research midwife MICHAEL DE SWIET, MD, FRCP, consultant physician Medical Research Council, Tuberculosis and Chest Diseases Unit, Brompton Hospital, London SW3 6HP PETER FAYERS, BSC, statistician Correspondence to: Dr Michael de Swiet. Introduction Methyldopa is the drug most commonly used by obstetricians for the treatment of hypertension in pregnancy.' Beta adrenergic blocking drugs are often used in non-pregnant subjects with hypertension, but there has been concern about their use in pregnancy.' Rubin et al, however, showed that atenolol was superior to placebo in the treatment of hypertension in pregnancy.3 Gallery et al compared methyldopa and oxprenolol and suggested that oxprenolol offered a specific advantage over methyldopa as pregnant women treated with oxprenolol were delivered of infants of greater birth weight.4 In an attempt to confirm this important finding we repeated the study in a larger series and also examined normotensive controls. Patients and methods All the women booked for delivery at Queen Charlotte's Maternity Hospital who had diastolic blood pressure of at least 95 mm Hg on two separate occasions at least 24 hours apart or greater than 105 mm Hg on one occasion were classified as hypertensive and entered into the study. A research nurse measured blood pressure using a random zero sphygmomanometer5; Korotkoff phase IV (muffling) was taken as diastolic blood pressure. The pressure was measured in the right arm after the patient had rested sitting for five minutes. No patients had asthma, heart failure, or heart block. Eleven patients who satisfied the entry criteria were excluded: six were taking other hypertensive medication, two had diabetes, one was expecting twins, one had renal disease, and one had congenital adrenal hyperplasia. The remaining 100 patients were allocated at random to receive either methyldopa or oxprenolol. To ensure homogeneity between the two treatment groups the randomisation was stratified into five gestational groups at entry: less than 20 weeks, 20 to 28 weeks, 29 to 32 weeks, 33 to 36 weeks, and more than 36 weeks. Although we analysed the data allowing for this stratification, the total number of patients entering the study at less than 32 weeks' gestation was small. For this reason and for simplicity of presentation and comparison with other studies the data were pooled and the groups divided into two subgroups: those entering the study at less than or equal to 32 weeks' gestation (early entry group) and those entering at more than 32 weeks' gestation (late entry group). Informed consent was obtained from patients before entry into the study. 1927