Study adds to evidence on clot risks of non-oral contraceptives

A study published on BMJ website today adds to the evidence that certain non-oral hormonal contraceptives (e.g. skin patches, implants and vaginal rings) carry a higher risk of serious blood clots (known as venous thromboembolism) than others.

The findings suggest that some women should switch from a non-oral product to a to help reduce their risk.

Several studies have assessed the risk of venous thrombosis (a collective term for and ) in women using oral contraceptive pills, but few studies have assessed the risk in users of non-oral .

These products more continuously release hormones into the body to prevent pregnancy.

A team, led by Professor Øjvind Lidegaard at the University of Copenhagen, reviewed data on non-oral hormonal contraceptive use and first ever venous thrombosis in all Danish non-pregnant women aged between 15 and 49 years from 2001 to 2010. All the women had no record of either blood clots or cancer before the study began.

Several factors that could affect the results, including age and education level, were taken into account.

The results are based on 9,429,128 observation years during which 3,434 confirmed diagnoses of first ever venous thrombosis were recorded.

The risk of venous thrombosis among women who did not use any type of hormonal contraception and who were 15-49 years old was on average two events per 10,000 exposure years. Women taking a combined oral contraceptive pill containing the hormone levonorgestrel had a three times increased risk (6.2 events per 10,000 exposure years).

Compared with non-users of the same age, women who used a skin patch had an eight times increased risk (9.7 events per 10,000 exposure years), while women who used a vaginal ring had a 6.5 times increased risk (7.8 events per 10,000 exposure years).

Use of a progestogen-only subcutaneous implant carried a slightly increased risk, while use of a progestogen-only intrauterine device did not confer any risk, and may even have a protective effect, say the authors.

Unlike combined pills, no reduction in risk was seen with long-term use of a patch or a vaginal ring.

Based on these findings, the authors calculated that 2,000 women using a vaginal ring and 1,250 women using a skin patch should shift to a combined pill containing levonorgestrel to prevent one event of venous in one year.

add to favorites email to friend print save as pdf

Related Stories

Some birth control shows higher clot risk: US

Oct 28, 2011

Some birth control products, including contraceptive pills, rings and patches for women, carry a significantly higher risk of blood clot than low-dose medications, US regulators said Thursday.

Study reveals contraceptive cancer risks

Mar 07, 2012

A study has revealed that injectable contraceptives that are widely used around the world influence the risk of developing several types of cancer.

Recommended for you

Triglycerides significantly elevated in women with GDM

15 hours ago

(HealthDay)—For women with gestational diabetes mellitus (GDM), triglycerides are significantly elevated throughout pregnancy, according to a review published online Jan. 22 in BJOG: An International Jo ...

Safer childbirth for women everywhere

22 hours ago

Few women in developed countries die of blood loss in childbirth, but in remote areas and developing countries, an estimated 100,000 die every year from post-partum haemorrhage. 

10 tips to prepare for pregnancy

Jan 29, 2015

For women of childbearing age looking to become pregnant, it is never too early to engage in healthy habits to ensure that she has a healthy pregnancy and her child has a healthy first step.

AAFP advocates for planned vaginal birth after cesarean

Jan 28, 2015

(HealthDay)—A planned labor and vaginal birth after cesarean (LAC/VBAC) is an appropriate option for most women with a history of prior cesarean birth, according to a clinical practice guideline published ...

Women diagnosed with PCOS twice as likely to be hospitalized

Jan 27, 2015

Women diagnosed with polycystic ovary syndrome - the most common hormone disorder in women of reproductive age - face a heightened risk of developing heart disease, diabetes, mental health conditions, reproductive disorders ...

User comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.