Latex Condoms Have Slight Edge For Pregnancy Rates

by Colette Bouchez

If you're using a condom to avoid pregnancy, the type you choose could make the difference.

That's the suggestion of a new study comparing latex and polyurethane condoms. Researchers from Family Health International in Durham, N.C., found that although pregnancy rates for both types were close -- similar to that of other barrier methods of protection such as a diaphragm - the latex condoms still had a 4 percent higher protection rate.

However, study author Markus Steiner contends the key factor in the difference could be the way in which the condoms were used rather than a difference in the materials.

"The higher risk of pregnancy in the polyurethane condom group compared to the latex condom group is likely the result of these condoms having a higher breakage and slippage rate, combined with the fact that study participants reported using them less consistently," says Steiner, a senior epidemiologist at Family Health International.

In addition to pregnancy rates, the study, which involved more than 900 couples, also looked at safety, breakage, slippage, discontinuation and acceptability factors, all of which could influence the outcome, Steiner says.

Although the difference in pregnancy rates was considered modest, Dr. Paul Blumenthal believes it could be a significant difference for some people.

"It may not be a public health difference, but it could be a personal difference, depending on who is using the condom and what their objectives are," says Blumenthal, director of contraceptive research and programs at the Johns Hopkins Bayview Medical Center.

"For someone who absolutely does not want to get pregnant, a difference of only 1 percent may be important -- a difference of nearly 4 percent is significant," Blumenthal adds.

Latex condoms, around since the 1800's, were one of the first reliable methods of birth control. Although numerous attempts have been made throughout the last century to develop male condoms made of alternative materials, such as polyurethane, to date, the U.S. Food and Drug Administration fails to deem any equal to latex in terms of both pregnancy and disease prevention.

As good as a latex condom can be, up to 7 percent of the general population has a latex allergy serious enough to cause significant problems if the condoms are used. Latex condoms can also break down when exposed to oil-based lubricants and are subject to breakage if not properly stored or used within a specific time after being manufactured.

The new study, published in the current issue of Obstetrics and Gynecology, was developed specifically to test a latex condom against a newly designed, looser-fitting and reportedly easier-to-use polyurethane one for pregnancy prevention.

To do so, researchers recruited 901 monogamous, fertile couples in good health between the ages of 18 and 35. Each couple agreed to have intercourse at least six times a month for six months using only a condom and no other type of birth control. All the women were free of any hormonal birth control for at least six months, and none of the couples had a latex allergy.

Each couple was randomly assigned to use either a latex condom or the eZon polyurethane condom for the test period, during which time they were to keep track of breakage, slippage or any genital irritations that occurred during use.

At the end of the study period, calculating all factors, the researchers found: The risk of pregnancy in the polyurethane condom group was approximately 9 percent, while the rate in the latex condom group was 5.4 percent. Slippage and breakage rates for the polyurethane group were 8.4 percent, compared to 3.2 percent for the latex group.

However, polyurethane bested latex in the area of female genital irritation, which was reportedly higher in the latex group.

Still, Steiner believes there is a place for the polyurethane condoms.

"For people with latex sensitivity or who find latex condoms unacceptable, the eZon polyurethane condom represents one of several synthetic male condom alternatives," he says.

More information: To learn more about all available methods of birth control, visit Planned Parenthood (www.ppfa.org). For more on condoms, visit SaferSex.org ( www.safersex.org).