'Six hundred pregnancies despite contraceptive implant," said the BBC. "500 fall pregnant after having contraceptive implant," said the Express. "Contraceptive implant alert," said the Daily Mail: "Hundreds of women fall pregnant after birth control fails."

The story first broke on Channel 4, and it's still not entirely clear why it's the biggest medical story so far this year. Some women have had some compensation: but a lot of people get a lot of payouts. There is a law firm touting for more business, but that's hardly news either, and the news story was: this contraceptive device has failed.

But is the failure rate exceptional? A figure means nothing if it has no context. Six hundred pregnancies sounds like a big number, but there is no way to know what it means unless we know how many women had Implanon, and for how long. The device was first launched in 1999, so that makes 60 pregnancies a year, which feels like a smaller number, but that is still not enough information. The figure that epidemiologists use for context is "person-years-at-risk".

The Medicines and Healthcare products Regulatory Agency estimates that 1.355m Implanon implants have been sold. Each implant lasts three years which gives a total exposure time of 4.06m women-years at risk.

So 584 unplanned pregnancies means there were 1.4 reported for every 10,000 women with Implanon implants per year, a failure rate of 0.014% per year. It means implants are still the most reliable form of contraception.

Back with our 584 unwanted pregnancies, we see the difference between individuals and statistics. For some of the people who got pregnant, from their end of the telescope, this is a disaster. Some cases may well have been avoidable. Some will want financial compensation, and you will have your own views on the state's role in this.

But for a potential user of the implant, or a news editor, looking at the whole population, at its worst, it still seems to be one of the most effective forms of contraception available even though this particular implant had a problem with insertion – which has already been improved on.

And lastly, just like a number deserves its context, so too does a scare. In the 1990s a temporary concern about a modestly increased risk of blood clot, particularly in one type of oral contraceptive pill, resulted in a mass abandonment of oral contraceptives generally, around the world, including among low-risk women, and the following years saw an increase in both pregnancies and abortions, with all that this entails. Words can do harm, just as surely as hormones can.