Combined oral contraceptives: do we know all of their effects?

Combined oral contraceptives are undoubtedly popular. By the end of the 1980's, an estimated 63 million married women around the world were using this method of contraception. In Britain, perhaps 95% of all sexually active women have used the pill at some time before their 30th birthday. Commensurate with such widespread usage, huge amounts of money have been spent during the past 35 years investigating the health effects of this method of contraception. Since it appears that all of the potential risks and benefits have now been identified, can we divert resources from pill-related research into new areas of activity. While this proposition may be attractive to funding bodies, and other researchers competing for increasingly scarce resources, it ignores the fact that several major uncertainties remain concerning the safety of combined oral contraceptives.