By Sheila Dwyer, Veins1 Staff
Reviewed by Jack Wylie, M.D.
The United Kingdom underwent a “Pill scare” five years ago after scientists linked some newer birth control pills to an increased risk of venous thrombosis, or blood clots in the lungs and legs. Many women there stopped taking the Pill, while in the United States, the Food and Drug Administration (FDA) waited for more information.
The original study performed five years ago contended that the incidence of blood clots is increased for women taking the newer, third-generation birth control pill, compared to those who took the older, second-generation Pill.
Now a study published by the British Medical Journal contradicts earlier findings. The scientists studied a group of women after the Pill scare of 1995. Fifty-four percent of the women surveyed before the Pill scare used the 3rd generation pill; after 1995, only 14 percent surveyed relied on this type of Pill for contraception. The majority of women who went off the 3rd generation Pill were under age 30, the most fertile group of women with the greatest risk for unintended pregnancy.
Medical experts studied the incidence of blood clots and discovered that it remained virtually the same in women taking the 3rd generation Pill before the scare and the women taking it in the years immediately after the scare. If, indeed, the original study was true and the third-generation birth control pills held twice the risk of venous thrombosis compared with second-generation, a reduction in use would then reduce the incidence of blood clots among women taking the Pill. No such difference was present.
The irony of this situation is that the risk of developing blood clots from the Pill is actually lower than the risk of developing clots while pregnant. Pregnancy increases the risk of venous clots six- to eight-fold, more than the risk while taking the Pill.
Researchers acknowledge that even though the Pill increases the risk of venous blood clots, that risk is very small. Doctors are hoping to change women’s attitudes toward the Pill, to get more young women to choose it again as their method of contraception. It is known that women who smoke, who have a high BMI (body mass index), and older women, all have higher risk of venous thromboembolism when on the Pill. However, because the overall incidence of blood clots in women of reproductive age is very low, an increase in risk may not be significant for most healthy women. Although women’s confidence in this third-generation Pill has waned, the good medical news is that a new, improved generation of birth control pills is currently being developed.