No abstract

In 200 healthy nulliparous women the mean arterial blood pressure in the second trimester (MAP-2 value) was calculated. 85 women (42 %) had a MAP-2 value of greater than or equal to 90 mmHg (positive test result), but only 27 women (32 %) developed a hypertensive complication. Conversely, 113 of the 115 (98 %) women with a negative test result (MAP-2 value less than 90 mmHg) remained normotensive. Only two women of this group (2 %) later showed a mild pregnancy-induced hypertension. Thus, the MAP-2 value has a high sensitivity (93 %) and a high predictive value of negative test results (98 %). On the other hand, there is a high rate of false-positive results (68 %) and thus a low predictive value of positive test results (32 %). It is concluded that the MAP-2 value is a simple method for selecting pregnant women who should be examined with other more specific predictive tests. Alternatively, weekly measurements of blood pressure are recommended for early diagnosis of hypertensive disorders of late pregnancy in all women with a MAP-2 value of 90 mmHg or more.

Prolactin may play an important role in the pathogenesis of pregnancy-induced hypertension (PIH) and preeclampsia. In 105 normotensive nulliparous women at 28 to 32 weeks of gestation, the relationship between serum prolactin concentration (PRL) and blood pressure behaviour was examined under standardized conditions. Neither postural change from left lateral to supine recumbency nor the infusion of low doses of angiotensin-II-amide had an effect on PRL levels. Similar mean PRL levels were found in pregnant women with a low angiotensin pressor dose (ADP less than 10 ng x kg-1 x min-1) or "angiotensin sensitivity", a positive supine pressor response (delta pd greater than or equal to 20 mmHg) or an increased serum uric acid concentration (greater than 3.6 mg/dl), which are criteria for an increased risk of developing hypertensive complications. However, in the group of subjects with angiotensin sensitivity, a significant correlation was found (a) between PRL levels and the APD and (b) between PRL levels and diastolic blood pressure increase after 5 min of supine recumbency. These results may reflect diminished dopaminergic activity in the central nervous system, which could influence both blood pressure and prolactin secretion.

The effect of high doses of ethinyl estradiol (0.4 mg/day) on renin substrate concentration, renin activity and aldosterone concentration in plasma was studied in eight ovariectomized women. Plasma renin substrate (angiotensinogen) increased already within 24--48 h, reaching a maximum on the third to fifth day after starting estrogen treatment. Thereafter, renin substrate concentration remained relatively constant in a range which was fourfold above the baseline levels. The increase of plasma renin activity was less pronounced and showed considerable between-patient variability; this increase was statistically significant only after 48 hours of estrogen intake. A rise in plasma aldosterone concentration was observed in two of four subjects examined. In one patient treated with 5 mg estradiol benzoate intramuscularly, plasma renin activity increased without any measurable change in renin substrate concentration. Only in one subject treated with ethinyl estradiol did plasma renin activity increase before plasma renin substrate concentration; the results presented do not preclude factors other than the stimulation of renin substrate synthesis in the liver from contributing to the activation of the renin-aldosterone axis during treatment with ethinyl estradiol.