Role of prolactin in pregnancy hypertension.

In 51 patients with pregnancy hypertension (H) and 51 normotensive gravid women (N), matched for age of gestation, plasma prolactin was measured at 8.30 am (PRL1) and 9.30 am (PRL2) in basal conditions and after 10 minutes of upright posture (PRL3). While in N there was a fall from PRL1 to PRL2 which was nonsignificant, in H there was a significant fall from PRL1 to PRL2. With upright posture there was a further decrease in prolactin in N and a significant increase in H. With multiple regression analysis, systolic and diastolic blood pressure did not show any independent relations with PRL1, PRL2 and PRL3, while serum proteins and proteinuria showed a significant relation with PRL1, as did serum proteins, serum potassium and serum urate with PRL2 and serum urate with PRL3. As has been suggested in primary hypertension, a certain increase in peripheral sympathetic tone, dependent on a decreased central dopaminergic activity, may be present in patients who develop pregnancy hypertension compared to normotensive pregnant controls and may be involved in the pathogenesis of pregnancy hypertension.