In a study of the effectiveness of systematic relaxation training alone or combined with biofeedback in the treatment of hypertension in pregnancy, 60 women were seen weekly for 6 weeks. 18 were given relaxation therapy alone (group A), 18 relaxation plus biofeedback (group B), and there were 24 controls. Whereas two-thirds of the control group had to be admitted to hospital during their pregnancies, less than a third of each experimental group had to be admitted. The experimental groups also had significantly lower systolic and diastolic blood pressure than the control group. There were no significant differences between groups A and B in hospital admission rates or blood-pressure measurements.