Conclusions: the relative safety of modern oral contraceptives

Published data on the relative safety of second and third generation oral contraceptives (OCs) is critically assessed. The original four studies published in 1995/1996 and their conclusions are examined in detail, including comments made by other investigators. Each study has advantages and flaws which are balanced in detail. Newer studies are then examined in the same manner. All recent papers indicate an equivalence of safety of second and third generation OCs, as the effects of various confounders and biases have been identified and analysed. We conclude that absolute risks are minor with both generations and that no reasons now exist to indicate any differences in their overall safety. We analyse finally how the pill crisis arose, and make suggestions about future reporting on OC safety.