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Birth Control/Chances of pregnancy


If birth control pills are 99.7% effective with perfect use what kind of effectiveness would you figure it is with missing one and taking 2 right away as recommended. Is it around  92%

It's a little hard to compare the two, since when we refer to 99.7% effectiveness, that means that if 1000 couples take the pill perfectly for 1 year, 3 women would get pregnant.  It doesn't refer to a single couple during a single month.  However, in missing one pill and taking 2 right away, chances for pregnancy are very slight, perhaps a 1% chance of pregnancy.  When we speak of statistical chances of pregnancy, we're referring to use over 1 year rather than single incidences during one month.

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Norman Solberg


I am an OB-GYN physician. I can answer almost any question related to women's health.


35 years in an active OB-GYN practice.

Fellow, American College of Obstetrics and Gynecology

MD OB-GYN specialist

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