Yaz, Yasmin & Ocella: Higher Risk of Blood Clots

As a

Yaz, Yasmin and Ocella Deep Vein Thrombosis, Pulmonary Embolism and Stroke Attorney,

we are providing this timely update. Watch the old Yasmin advertisement here.

According to a recent population-based study, newer forms of progesterone in contraceptives result in higher venous thromboembolic (VTE) risk than older drugs.

According to Ojvind Lidegaard, MD, of Rigshospitalet at the University of Copenhagen, Denmark, an international expert, women on the pill with the older, levonorgestrel version were at three times the risk of VTE as those not on any hormonal contraception.

But oral contraceptives containing desogestrel, gestodene, drospirenone, or cyproterone boosted the risk six to seven times over that of non-users, the group reported in BMJ.
The researchers explain that newer forms of progesterone in combination hormonal contraceptives carry higher venous thromboembolic (VTE) risk than older forms.

Furthermore, they point out that this study found that women on the pill with the older, levonorgestrel version were still at threefold elevated risk of VTE compared with those not on any hormonal contraception, whereas those on the newer versions were at six and sevenfold risk.

The Food and Drug Administration is already studying the possible increased risk of blood clots with pills containing the drospirenone. The F.D.A. says its preliminary results suggest a 1.5-fold increased risk compared with other hormonal contraceptives, to about 10 women in 10,000 from 6 women in 10,000.

These findings were based on the national registry data in Denmark from 2001 through 2009, after the launch of the newest synthetic progesterone, drospirenone.

Other studies over the decades also have found almost universally elevated VTE risk with hormonal contraception, with the estrogen and progestogen (synthetic progesterone) components both appearing to play a role.

The risks appear real and may lead many clinicians to prescribe a combined oral contraceptive with levonorgestrel whenever possible.

The updated analysis included more than 1.2 million non-pregnant 15- to 49-year-old women in Denmark without a history of thrombotic disease. Data came from national vital status, inpatient, cause of death, and pharmacy registries.

From 2001 to 2009, 4,307 first-ever VTEs occurred in this cohort. Most were deep vein thrombosis only (63.6%) or pulmonary embolism with or without deep vein thrombosis (26.2%).

Compared with women not taking hormonal contraception, confirmed venous thromboembolism was elevated for users of oral contraceptives containing 30 to 40 μg ethinylestradiol plus the following:

Levonorgestrel, with a relative risk of 2.9
Desogestrel, with a relative risk of 6.6
Gestodene, with a relative risk of 6.2
Drospirenone, with a relative risk of 6.4

With levonorgestrel-containing pills as the comparator, rate ratios of confirmed venous thromboembolism adjusted for length of use were:

2.2 with desogestrel
2.1 with gestodene
2.1 with drospirenone

Lower estrogen doses were associated with modestly lower VTE risk for oral contraceptives with norethisterone, levonorgestrel, desogestrel, or gestodene but not with drospirenone, the investigators reported.

More information
The American College of Obstetricians and Gynecologists has more about birth control pills.

Primary source: BMJ
Source reference:
Lidegaard Ø, et al "Risk of venous thromboembolism from use of oral contraceptives containing different progestogens and oestrogen doses: Danish cohort study, 2001-9" BMJ 2011; 343: d6423.

Additional source: BMJ
Source reference:
Hannaford PC "The progestogen content of combined oral contraceptives and venous thromboembolic risk" BMJ 2011; 343: d6423.

Jick S, Hernandez R "Risk of non-fatal venous thromboembolism in women using oral contraceptives containing drospirenone compared with women using oral contraceptives containing levonorgestrel: case-control study using United States claims data" BMJ 2011; DOI: 10.1136/bmj.d2151.
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