Can your birth control let you down?

I read an interesting article in The New York Times recently about how birth control may not be as effective as we were led to believe.  The article focused not only on misuse of contraceptive methods but also extended use over long periods of time.

Typically when we hear about contraception failing it is due to misuse.  For example a condom breaking or someone has forgotten to take their pill at the same time every day. When we do hear reports of failure with correct use it's usually within the first year of using that method.  The topic of failure that is less understood is the risk that builds up over time when using the same method for many years.
Most people would think that they longer they are on something the safer they are.  The truth is the longer you use a certain method of contraception the greater your risk for unplanned pregnancy.  This rings true for all methods of contraception, even if they are used correctly every time.

The following charts are from the article I read. They illustrate the probabilities or pregnancy while using each method alone for up to 10 years.  The red line represents typical use.  This shows the effectiveness of each method for the average couple who may not always use it perfectly each time.  The dotted line represents perfect use.  This is the effectiveness of each method when used exactly as directed and followed perfectly.  Not many couples can attain perfect uses especially over long spans of time.

Below are the stats I gathered from their charts in the article:

Contraceptive	Typical Use	Perfect Use
Spermicide	96/100	86/100
Awareness Based Fertility	94/100	26/100
Sponge (after child)	94/100	89/100
Withdrawl	92/100	34/100
Female Condom	91/100	40/100
Male Condom	86/100	18/100
Diaphragm	72/100	46/100
Sponge (before children)	72/100	61/100
Pill, Evra patch, NuvaRing	61/100	3/100
Depro-Provera	46/100	2/100
Copper IUD	8/100	6/100
Female Sterilization	5/100	5/100
Male Sterilization	2/100	2/100
Levonorgestrel IUD	2/100	2/100
Hormonal Implant	1/100	1/100

Here's how they calculated the numbers: "The probability that a woman doesn't get pregnant at all over a given period of time is equal to the success rate of her contraceptive method, raised to the power of the number of years she uses that method."

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Sources:

• http://www.nytimes.com/interactive/2014/09/14/sunday-review/unplanned-pregnancies.html?WT.mc_id=2015-Q1-KEYWEE-AUD_DEV-0101-0331&WT.mc_ev=click&bicmp=AD&bicmlukp=WT.mc_id&bicmst=1420088400&bicmet=1451624400&ad-keywords=FEBAUDDEV&kwp_0=8791&kwp_4=73564&kwp_1=124173&_r=0