Cape Town - An American gynaecologist visiting South Africa has debunked claims that combined hormonal contraceptives are putting women’s health at risk by increasing the chances of blood clots.
Professor Lee Shulman, from North-Western University in Chicago, argued that life experiences such as pregnancy, post-delivery, obesity and ageing were more likely than oral contraceptives to cause blood clots in women.
While oestrogen-based contraceptives had been associated with a risk of blood clots for many years, the risk had remained low, Shulman said.
In the UK, the department of health has told doctors to warn women following “new evidence” on the risk of blood clots associated with combined hormonal contraceptives.
The US Food and Drug Administration (FDA) – which reviewed epidemiological studies of the risk of blood clots in women taking drospirenone – also cautioned health providers to consider the risks to women before prescribing such a pill.
Drospirenone is a synthetic version of the female hormone progesterone, also referred to as a progestin.
Combined contraceptives contain synthetic versions of the hormones oestrogen and progesterone.
It is oestrogen that is associated with the risk of blood clots, although the type of synthetic progesterone hormone used in the combined contraceptive can influence the risk to a certain extent.
Shulman measured the risk of blood clots among pill users as being four to 10 000 woman years. This was significantly lower than the risk among pregnant women, which was measured as being eight to 10 times.
The risk of blood clots among women who had just given birth was even higher, as the volume of blood accumulated during pregnancy was reducing fast, while there were also hormonal imbalances.
Shulman said that given the low risk of blood clots among pill users, there was no reason to panic and women should continue using it as a choice of contraception.
“The benefits far outweigh the risks. If you are using a pill, and you are in perfect health and you are not overweight, there is no need to worry about blood clots. These are safe, highly effective medicines for preventing unintended pregnancy and the benefits far outweigh the risk of clots.” - Cape Argus