Newer Oral Contraceptive Pills Three Times More Likely to Develop Blood Clots

A study has found that there is an increased risk of blood clots with the newer types of oral contraceptives.

According to Fox News, the study has found that women who are taking any form of combined oral contraceptive pills are three times more likely to develop blood clots, known as Venous thromboembolisms (VTEs), in the deep vein of a leg or the pelvis.

Though VTE is a common phenomenon, researchers fear that if a clot were to dislodge and travel to the heart, brain, or lungs, a fatal end-result is bound to happen.

For the study, researchers studied U.K. general practice databases covering the period between 2001 and 2013. The time period was chosen to better assess VTE risks between women who took the older version of the pill and those who took newer-generation pills.

In the databases, researchers found 5,062 cases of women had VTE from age 15 to 49. These women were placed in five different groups. Each group consisted of women similar in age and treated in similar fashion.

The researchers then took into account other factors that could lead to blood clots. These other risk factors include: smoking, alcohol consumption, race, and body mass index, among others.

Lead researcher Yana Vinogradova, from the University of Nottingham, spoke to Time about the results of the study via email.

She said, "Our study suggests that the newer contraceptives have a higher risk of [blood clots] than the older agents...."

"The risk was highest for people taking the Pills that contain newer types of the progesterone hormone, such as drospirenone, desogestrel, gestodene, and cyproterone, as compared to people taking the Pill with first-generation versions of the hormone (levonorgestrel and noresthisterone)," Vinogradova added.

The difference between the older and newer oral contraceptives is the form of progesterone they contain. Since the introduction of the pill in the 1960s, drug developers have "tweaked" the progesterone side of the pill to lower certain side effects like acne, headache and weight gain.

According to Time, it seems that the "price for those modifications may be more blood clots."

To avoid the risk of developing blood clots, Vinogradova says, "Doctors need to consider all health issues when prescribing contraceptives, selecting a drug type associated with the lowest risk for patients with particular susceptibilities."