MEASUREMENTS OF BLOOD-PRESSURE, EDEMA AND PROTEINURIA IN A PREGNANT POPULATION OF NEW-ZEALAND

This is the first report of the largest study of blood pressure measur ement in pregnancy in a New Zealand population using standardized defi nitions and methodology. Over 3,800 women who delivered in an 8-month period in the Wellington region were included in the study. Blood pres sure measurement and the presence of oedema and proteinuria were recor ded from booking until delivery and in the puerperium. Only 2.7% of wo men were unable to be contacted after delivery for details on outcomes . The results established normal ranges for blood pressure throughout pregnancy. The data show that blood pressure greater than 140/90 until 35 weeks' gestation is outside 2 standard deviations at all gestation s and justifies using these measurements as the definition of hyperten sion in pregnancy. The fall in blood pressure in the 2nd trimester was less than 1 mm Hg per week in both the systolic and diastolic pressur es. This fall was smaller than previously recorded in other studies. G estational hypertension was the commonest blood pressure abnormality o ccurring in 15.2% of the population. This represented 69% of the pregn ant women with a hypertensive disorder. The overall incidence of both gestational hypertension and preeclampsia was 18.5% which is higher th an reported in other parts of the world. In this study obesity was sig nificantly associated with hypertensive disorders in pregnancy. An arm circumference of >33 cm, one of the measurements of obesity, was foun d in 6.8% of the study population. Even after the effect of arm circum ference was taken into account, hypertensive disorders were also more common in Pacific Island women. Ankle oedema was significantly associa ted with the development of both gestational hypertension and preeclam psia but the incidence of oedema was noted in only 11.9% of the subjec ts.