Effective or not?
WASHINGTON, USA (AP) – Here, a nurse holds an injectable hormonal contraceptative, along with the traditional pill, at a Planned Parenthood of Central New Jersey clinic in Shrewsbury, New Jersey.
Studies show that lower-dose birth control pills are less effective at preventing pregnancy than the first oral contraceptives approved beginning in 1960. Yet the newer drugs offer other health benefits or cause fewer side effects. That has split federal health officials on the need to define a pregnancy or failure rate that would be unacceptably high for next-generation pills.
Throughout the 1960s, the earliest birth control pills to win Food and Drug Administration approval failed just once per 100 woman-years of use. That is, for every 100 women taking the pills for a year, there was fewer than one pregnancy on average among them.
Today, newer pills contain less oestrogen and progestin. Those pills can reduce the risk of blood clots, stroke and other sometimes deadly side effects. But as the hormone content of the pills has dipped, failure rates have climbed.
Over the last decade, the FDA has approved some pills with failure rates that exceed two pregnancies per 100 woman-years of use, according to agency documents. That is twice the rate considered acceptable in the 1960s.
But allowing the less effective pills on the market can increase the options for women and their doctors, said Dr Charles Lockwood of Yale University, acting chairman of FDA’s reproductive health drugs advisory committee. As while most women take the pill to prevent pregnancy, others rely on hormonal contraceptives to regulate their monthly periods or curb acne.
The FDA is looking at how well studies done prior to approval of new birth control pills reflected their “real-world” use. Typically, that use is less consistent and reliable than it is in clinical studies.
Nearly 12 million US women were on the pill as of 2002, making it that country’s leading method of contraception, according to a recent Centres for Disease Control and Prevention study.
