Background

The combined oral contractive pill (COC) has been available for over 50 years but are we providing women with the regimens they want? As far back as 1977, Louden et al.1 reported the use of 84 active pills with a 7-day break to free women from monthly periods, yet menstrual manipulation is underused today. So why do we have a 21/7 regimen for pill-taking?

A brief history

When oral contraceptives were first developed, though the pioneering work of George Pincus, Carl Djerassi, Frank Carlton and John Rock, the presence of seven pill-free days allowed a withdrawal bleed that mimicked the natural cycle. The aim of this was to make a novel concept more acceptable. Dr Rock stated the 21/7 regimen was a “morally permissible variant of the rhythm method”,2 which was very important for the USA in the 1950s where birth control was illegal. Having a withdrawal bleed also gave women reassurance that they were not pregnant. The decision to adopt this approach was therefore social rather than physiological.

Acceptance of modern-day hormonal contraceptives has increased over time. Many women no longer wish to bleed each month and request ‘an absence of withdrawal bleeds’ to fit in with their busy lives. This has become possible with ethinylestradiol (EE) dose reduction and the introduction of new progestogens in novel COC regimens. Lowering the dose of synthetic estrogen means that the total intake of hormones is less with 20 µg pills taken continuously when compared to 30 µg pills taken with the traditional 7-day hormone break each month. When low-dose estrogen is combined with newer highly selective progestogens good cycle control results, making these hormones ideal partners for flexible extended regimens.

In the 1980s, tricycling of pills (putting three packets of COCs together followed by a 7-day break) became more commonplace but, despite Seasonale^® [containing …