HAEMODYNAMIC EFFECTS OF COMBINED OESTROGEN/PROGESTOGEN ORAL CONTRACEPTIVES

Summary The effects of a combined contraceptive pill, and of its oestrogen and progestogen components, on the haemodynamics in the recumbent and upright positions were studied in 49 healthy young women. Twenty‐nine women were given a contraceptive pill containing 2.5 mg. of lynestrenol and 0.075 mg. of mestranol (Lyndiol 2.5) for two months, while 10 women received mestranol only and 10 women lynestrenol only for 10 to 13 days. A significant increase in cardiac output, blood volume and stroke volume was observed after combined oral contraceptive therapy. Similar changes were recorded in the women given mestranol, but not in those given lynestrenol. The tilt response was not influenced by any treatment. The present results indicate that the haemodynamic changes observed during combined (oestrogen/progestogen) oral contraceptive treatment are caused by oestrogens.