New lower-dose birth control pills are less effective than old, regular-dose pills.
Women are hearing that the newer generation of oral contraceptives has TWICE the failure rate for preventing pregnancies than the older ones.
FDA says that there seems to be a trend for an increase in pregnancies with the newer low-dose ( 35 mcg estrogen) birth control pills. But we're talking just 1 or 2 more pregnancies per 100 women on contraceptives for a year.
The lower dose pills might be less forgiving of a missed pill. And there's evidence that the pill and the patch may not work as well if a patient is overweight. Many researchers recommend using oral contraceptives with at least 30 mcg ethinyl estradiol in women weighing over 154 pounds.