It Carries Just a Slightly Higher Increase of Clots, Studies Indicate

By Joy Victory (Feb. 17, 2006)

Is the birth control patch more dangerous than other forms of hormonal contraceptives?

Yes, but just barely, studies indicate so far.

All forms of female hormonal birth control carry a higher risk of strokes, clots and heart attacks, because they contain estrogen, which increases that risk, especially among women who smoke.

But the patch is a bit more risky because of the way it works. It works transdermally, or through the skin, delivering a higher level of estrogen than birth control pills do. The patch's manufacturer, Ortho Women's Health & Urology, makes this clear:
"Hormones from patches applied to the skin get into the bloodstream and are removed from the body differently than hormones from birth control pills taken by mouth," states the drug's product information posted on the company Web site. "You will be exposed to about 60 percent more estrogen if you use [the] Ortho Evra [patch] than if you use a typical birth control pill containing 35 micrograms of estrogen. In general, increased estrogen exposure may increase the risk of side effects."

But, in reality, the overall risk of adverse side effects is very low. For women not taking any birth control pills, there is a one in 10,000 chance of suffering a venous thrombosis (leg clot), and that risk increases to about three to four in 10,000 when hormonal birth control is used. Various estimates place the patch at about twice that, or a chance of six to eight per 10,000.

The federal Food and Drug Administration does not plan to take any action on the patch just yet and said more evaluation was needed, according to a Reuters report.

So how do women choose which method of hormonal birth control to use? It's an issue they should discuss with their doctors, especially if they smoke, have high blood pressure, blood-clotting problems or are overweight.

ABC News