Common reasons for condom failure

Dear Ludek,

Condoms can fail to prevent pregnancy when they are:

• Not used correctly
• Used inconsistently
• Broken during sex
• Manufactured improperly
• Damaged after manufacture
• Expired

Approximately two to five percent of condoms tear during use. The majority of these failures are caused by human error, which can include not using enough lube and creating microscopic tears with rings or long, sharp, or jagged fingernails, among other possibilities.

Incorrect use includes unrolling a condom backwards, not unrolling the condom to the base of the penis, not leaving a half-inch of empty space at the tip of the condom, and not holding the rim of the condom down along the base of the penis when removing the penis after ejaculation. Inconsistent condom use means not using a condom every single time a person has sex, or not putting the condom on soon enough — that is, before the penis comes in contact with his partner's genitals. Any risk of pregnancy resulting from pre-cum on the fingers being transferred to a condom is unlikely. To be extra safe, a man could put on a condom at the very beginning of sexual play, rather than wait until he's ready for penetration. Condom failure may also be more likely if either partner has pierced genitals.

A condom that breaks when used correctly most likely resulted from hidden weaknesses in the rubber. These weaknesses may get past manufacturing regulation as some tests administered for strength and leaks are used to spot check a batch of condoms as opposed to testing each individual condom. The U.S. Food and Drug Administration (FDA) sends inspectors to different condom manufacturers to carry out water leakage tests, which determine if there are holes in the condoms, and air-burst tests, which link a condom's air-burst volume to its resistance to breakage during sexual activity. In the water leakage test, if more than four out of 1000 condoms have leaks, the entire lot is destroyed. For the air-burst test, no more than one-and-a-half percent of the condoms in the lot can fall short of the required pressure and volume limits. Interestingly, condoms do not have to pass a friction test.