Effect of vaginal lubricants on sperm function and fertility

Background

Vaginal lubricants are often used to treat vaginal dryness during intercourse. For couples trying to conceive, vaginal dryness can be an even bigger problem since they need to have scheduled and more frequent intercourse around the time of ovulation.

About 75% of couples who say they are “trying to conceive” also say they experience vaginal dryness. Many couples have tried various types of vaginal lubricants to help with this problem. However, some studies have suggested that when mixed with human semen during intercourse, these lubricants may affect sperm integrity and function, thereby decreasing the potential for fertilization. Lubricants may also affect the movement (motility) of sperm. For couples with infertility, it would be of great concern if the lubricant they chose caused less sperm to be able to move or caused the sperm to move more slowly.

Another concern is sperm DNA damage. Inside a sperm, the DNA is packed tightly around protein “blocks” to prevent damage and to ensure that the DNA is packaged efficiently in the small space. Even with this protection, some DNA could still be damaged or fragmented along its journey to reach the egg.

In 2008, a study was performed to determine the effects of vaginal lubricants on fertility. Researchers compared four vaginal lubricants: FemGlide, Pre~Seed, Replens, and Astroglide to determine their effects on sperm motility. Three others lubricants including FemGlide, Pre~Seed, and K-Y Jelly were tested to evaluate their effects on sperm DNA damage.

Experiment

The experiment consisted of two parts. 13 male donors known to have normal fertility gave semen samples for testing.

In the first part of the study – testing sperm motility- the semen samples were diluted and 10% solutions of FemGlide, Pre~Seed, Replens, and Astroglide were added to the semen. This percentage was chosen on the basis of the lubricant concentration after intercourse and ejaculation. After 30 minutes at body temperature, the solutions were evaluated using a microscope. This time frame was chosen based on studies showing that it takes 15-30 minutes for the majority of fertilizing sperm to travel through the cervix after ejaculation.

The second part of the experiment tested the effects on the sperm DNA. The solutions were again cultured for 4 hours at body temperature. FemGlide, Pre~Seed, and K-Y Jelly were each added to the sperm samples. Because of the previous accounts that KY Jelly reduces sperm function, KY is used here as the negative test. After the allotted amount of time, the sperm were analyzed for the percent of damaged fragmented DNA.

Replens and Astroglide were shown to lower sperm motility after 30 minutes. FemGlide also reduced the motility but to a lesser significance. Pre~Seed, however, did not change the sperm motility in the samples tested. As for the second experiment, FemGlide and KY Jelly increased sperm DNA damage by 10% or more as compared with the control. Pre~Seed showed some damage, but not enough to be considered a problem.

Discussion

The sperm damage seen is most likely due to the non-physiologic properties of these lubricants. Optimal sperm survival occurs when very specific conditions are met. For example, if the environment is too acidic or not acidic enough, sperm can be adversely affected. These lubricants may cause an alteration of the vaginal environment and therefore cause sperm damage.

Conclusions

Is there a link between vaginal lubricants and fertility?

Many physicians are still recommending lubricants or saliva to the infertile couples who are dealing with vaginal dryness. In this study, the researchers found that PreSeed intimate moisturizer had minimal negative effects on sperm motility and DNA quality as compared with FemGlide, Astroglide, K-Y Jelly, and Replens. For couples trying to conceive, it is important to remember that even non-spermicidal lubricants, such as these, could reduce sperm function.

The results suggest that PreSeed may be a promising treatment for vaginal dryness in infertile couples trying to conceive. However, the result of this one study is not enough to definitively say that the chances of getting pregnant while using these products is significantly less or that one brand is better than another. In fact, in 2012 another study asked women to keep a diary of their vaginal lubricant use while they were trying to get pregnant. The results showed that women who used vaginal lubricants conceive at the same rate as women who did not use vaginal lubricants.