It’s time to take a step back and get a little perspective.
A study published in The BMJ today suggests a link between newer contraceptive pills and higher risk of serious blood clots. The finding is not new, but it may be cause for a different kind of concern.
During their fertile years, between three and five women of every 10,000 who are not pregnant and not taking the pill are likely to develop blood clots every year. The research published today found older contraceptive pills double this “background” risk of blood clots, and the newer pills have roughly doubled the risk again.
Several studies published over the past 20 years show very similar findings. What this research brings to the table are larger numbers of women and more careful attention to factors in their medical history that could potentially skew the results.
It’s likely the media will pounce on this story; there will be testimonies from women who have experienced blood clots while taking the pill and a plethora of personal injury lawyers spruiking their business. Women across the world will be scared into stopping their contraception until it all blows over. I know this because I’ve seen it before, and I think that’s what we should be concerned about.
We’ve known the pill increases a woman’s risk of blood clots and stroke since it was first marketed. By the 1990s, concern had been tempered by the fact that this risk was greatly reduced by pills containing only a quarter of the oestrogen compared to the 1960s. The development of several newer progestogens in the 1980s had also increased the range of pills available, making it more likely that most women could find a combination that suited them.
But then, in 1995, three studies published in The Lancet suggested pills containing these newer progestogens posed twice the risk of blood clots as the older ones, just as the study published today does. Frenzied media coverage of the finding led many women to simply discontinue their contraception.
As a result, 1995-96 saw a 9% increase in abortion rates in Britain as well as a 25% increase in births. And both pregnancy and birth hold significantly higher risks of blood clots than any contraceptive pill, with rates at least ten times higher.
Within a few years, the controversy settled down somewhat when a number of epidemiologists pointed out that doubling an extremely small risk has no significant public health impact. But then, between 2007 and 2014, it all started again when a number of studies reached conflicting conclusions about whether there were any real differences in clotting rates between various pills.
Read more: Is 14 too young to take the pill?