Prescribers must put the increased risk of blood clots associated with newer contraceptive pills “in perspective”, the Royal College of General Practitioners (RCGP) has said.
 
The risk of venous thromboembolism (VTE) among women taking the latest generation of oral contraceptives - which contain desogestrel, gestodene, cyproterone or drospirenone - was almost twice as high as those taking older contraceptives containing levonorgestrel, according to the authors of a report published in the British Medical Journal (BMJ) on Tuesday (May 26).
 
RCGP treasurer Helen Stokes-Lampard said prescribers should be aware that older pills were “associated with a slightly lower risk” of VTE. “But this must be kept in perspective as the new pills have some advantages in terms of fewer side effects,” she said on the day the study was published.
 
Healthcare professionals should make a decision on which contraceptive to prescribe that was “specific to the patient’s needs and her previous experience”, Dr Stokes-Lampard stressed.

 
The study’s findings

The BMJ said the study’s Nottingham University authors had compared more than 10,500 cases of VTE among women aged 15-49 years who were taking combined oral contraceptives with about 42,000 matched controls. The authors concluded that the risk of developing VTE among women taking older contraceptives - which contain levonorgestrel, norethisterone or norgestimate - was around two and a half times greater than those who took none.
 
Women on newer contraceptives had an increased risk of around four times greater than women on no contraceptives, the study’s authors said.
 
The authors noted that additional cases of VTE would be expected across women on any types of combined oral contraceptives compared with those taking none.
 
The highest risk was among 25-49 year olds taking either desogestrel, cyproterone or drospirenone, who would be expected to show an an extra 17 cases of VTE per 10,000 women, the researchers said. Women in this age group taking either levonorgestrel or norgestimate contraceptives would only be expected to show an extra seven cases, they added.
 
Dr Stokes-Lampard said that women taking contraceptive pills should be “reassured by the findings” as they “support what we already know”. “Most importantly, they should not change or stop their contraceptives,” she added.
 

How do you advise pateints on the risks of oral contraceptives?

We want to hear your views, but please express them in the spirit of a constructive, professional debate. For more information about what this means, please click here to see our community principles and information