Hypertension in pregnancy: A 24-year study of 864 consecutive cases

Objectives: To evaluate clinical data from a group of pregnant women with h ypertension who were observed during a 24-year period and to assess posible changes in the presentation of the different forms of hypertension in preg nancy over the last decade. Methods: From 1973 to 1996 we have studied a group of 864 women with hypert ension-complicated pregnancies: 238 in the retrospective analysis, 626 in t he prospective study. Data from each patient included a clinical history, b lood and urine analysis, and maternal and fetal morbidity and mortality. Th e control group consisted of 607 women with normotensive pregnancies observ ed in the same 24-year period. The observation time was divided into three 8-year periods for evaluation to evolutive assessing: 1973-1980 1981-1988 a nd 1988-1996. Results: Women with hypertensive pregnancies were older than controls (29.5 +/- 6 versus 26.2 +/- 5 years old, p < 0.05) and suffered from a higher fe tal (7.1% versus 0.3%, p < 0.001) and maternal (0.3% versus 0%) mortality. No maternal deaths were observed during the last 11 years. The highest rates of preterm delivery and fetal mortality were founding ecl ampsia (45% and 21%, respectively), and preeclampsia superimposed on chroni c hypertension (50% and 21%, respectively). The lowest were observed in the gestational hypertension cases (10% and 2%, respectively). The prevalence of the different forms of hypertension in pregnancy showed s ome evolutive changes. Eclampsia became less common its prevalence being 12 % in the first period and 1% in the third one (odds ratio = 11.3, 95% confi dence interval 3.9-12.8%; p < 0.001). The prevalence of gestational hyperte nsion increased from 30% in the first period to 47% in the third one (odds ratio = 2.1, 95% confidence interval 1.5-3.0; p < 0.001) and it became the most frequent form of hypertension in the two last periods. Fetal mortality in the three mentioned periods was 13%, 7% and 2% respectively. Conclusions: Gestational hypertension is, today, the most frequent form of hypertension in pregnancy. The prevalence of has eclampsia decreased contin ually, and at present is an unusual entity. Fetal mortality associated with hypertension in pregnancy has been also diminishing in recent years and ma ternal mortality related to these disorders has disappeared.