Pfizer recalls 1 million birth control packets over pregnancy concerns

Progestin-only contraceptives were listed as possible carcinogens.

(CBS/AP) Pfizer announced it's recalling 1 million packets of birth control over a packaging mix-up that could raise the risk for an unplanned pregnancy.

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The mix-up affects 28 lots of birth control pills: 14 lots of Lo/Ovral-28 tablets and 14 lots of generic Norgestrel and Ethinyl Estradiol tablets. Both products are manufactured by Pfizer Inc. and marketed in the U.S. by Akrimax Rx Products under the Akrimax Pharmaceuticals brand.

Click here to see a picture of the birth control packets in question.

What's wrong with the pills? Pfizer found that some birth control packets had too many active tablets, while others had too few. That's an issue, since oral birth control products use a series of 21 drug tablets and 7 inactive sugar tablets to regulate the menstrual period for the month while providing contraception. That could leave women with an inadequate dose of the hormones and raise the risk that they will get pregnant accidentally. The recalled pills do not pose a safety risk.

"Consumers exposed to affected packaging should begin using a non-hormonal form of contraception immediately," Pfizer spokesperson Grace Ann Arnold, said in a written statement.

A company spokeswoman said the problem was caused by both mechanical and visual inspection failures on the packaging line and the problem has since been corrected.

The affected packets have expiration dates ranging between July 31, 2013, and March 31, 2014. Lot numbers are available at the FDA's website.

If you have a pill package that has a recalled lot number, the FDA says notify your doctor and return it to the pharmacy.