| Citation | Vessey has made major contributions to knowledge of the effects of different forms of contraception on women's health and of the factors affecting female fertility. He was the core member of a group of investigators who provided the first clear evidence that steroid contraceptives could cause venous thrombosis, cerebral thrombosis, and myocardial infarction. Subsequently he designed and carried through a unique study which has kept 17,000 women under detailed observation for more than 20 years, recorded all the reasons for which they have attended hospital as in or out patients, and has consequently permitted assessment of the relative benefits and the hazards associated with the use of steroid contraceptives, intra-uterine devices, and diaphrams [sic], their contraceptive efficiency, and their effects on fertility and many diseases. |