New Zealand study on oral contraceptives published

New Zealand study on oral contraceptives published

The Ministry of Health is today releasing the results of a study published in "The Lancet" examining the risk of death from pulmonary embolism in women taking oral contraceptive pills.

The research, commissioned from Otago University Professor of Preventive and Social Medicine David Skegg and colleagues by the Ministry of Health, shows that 17 women taking oral contraceptives died of a pulmonary embolism - a blood clot in the lungs - between 1990 and August 1998. Since the study was commenced a further three cases have been reported, bringing the total deaths to 20 between 1990 - 1999. The study concludes that for every 100,000 women taking the pill, one woman per year will die from venous thromboembolism - a blood clot in the veins. Given usage in New Zealand these results indicate that two NZ women may die each year from blood clots associated with taking oral contraceptives.

Published in The Lancet today the study was yesterday considered by the independent Medicines Adverse Reactions Committee, which advises the Ministry of Health's Medsafe division.

Both have reiterated the advice that women keep taking the pill and discuss any concerns with their general practitioner or family planning clinic.

Medsafe spokesman Dr Stewart Jessamine said the committee examined the results of Professor Skegg's study in conjunction with other international literature. It concluded that although the number of deaths is higher than previously reported or estimated, the results are similar to those found in a British study.

"Clearly each of these deaths is a tragedy for the families concerned and I want to acknowledge that and extend to them our sympathy.

"Although this will be no consolation at all to those already affected, this comparability with overseas results suggests that overall the risks are not significantly greater than thought. It is in this context that MARC and Medsafe have concluded that as long as women are fully informed of the risks they should continue to have the right to choose to take whichever oral contraceptive they wish."

Blood clots are associated with both second and third generation oral contraceptives.

"Professor Skegg's research is consistent with the results published in earlier studies that third generation pills containing gestodene or desogestrel are approximately twice as likely to cause blood clots as second generation pills containing either levonorgestrel or norethisterone," Dr Jessamine said.

Blood clots occur in the veins of the leg where they may cause a blockage. In some cases pieces of the clot dislodge and travel to the lung - a pulmonary embolism. Treatment of blood clots involves admission to hospital and ongoing treatment to thin the blood. Some patients are left with ongoing problems such as pain and swelling at the site of the blood clot in the legs.

Dr Jessamine said the study supported the need for doctors to continue to advise women about the benefits and risks of taking oral contraceptive pills; and to assess each woman carefully for risk factors.

Some of the risk factors for blood clots are a previous blood clot, a close family member who has had a blood clot, being overweight, bad varicose veins, cancer, recent surgery and being immobilised.

"While changing a woman over to a second generation pill can be expected to reduce her risk of a blood clot by half, some women prefer third-generation pills. The available evidence is that women are already making informed decisons on the basis of the information we have provided - since 1996 the use of third generation pills has dropped by over 50% and they now account for only 35-40% of the market," Dr Jessamine said.

"Studies confirm that for most women the oral contraceptive is an extremely safe and reliable form of contraception. We believe a rigorous application of informed consent is the best option and the Medicines Adverse Reactions Committee has advised that it is not necessary to remove these pills from the market or restrict access in some other way, The decision to re-iterate our earlier advice is based on a reassessment of all of the available information and we would advise women to continue taking their contraceptive pill and to talk to their general practitioner or family planning clinic if they have any concerns about the product they are taking, " Dr Jessamine said.

Doctors are being alerted to the research, reminded of the risks and advised to take careful histories and give full information before prescribing oral contraceptives. Medsafe is re-issuing a consumer safety leaflet, reactivating an 0800 number for women seeking more information and carrying out some print advertising.

The 0800 number is 0800 930 039

ends

For more information contact: Peter Abernethy Communications Manager Ministry of Health Tel: 496 2008/025 477 036

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