Birth Control Made Easier: Scientists Found Sperm’s Power Switch—And a Way to Turn It Off

The ancient birth control techniques ranging from using linen to animal bladder sheaths have evolved with time and new age discoveries. The effective and safe contraception or fertility control methods were available from the twentieth century including condoms, IUDs, birth control pills, vasectomy and tubal ligation. Scientists knew very little about the process of fertilization on a molecular level. Discovery of the crucial mechanism of the reproduction can pave the way for new fertility treatments which will eventually improve the fertility rates. Alternatively, it can lead to the production of unisex contraceptive.


In simpler words, sperms need to be kept away from eggs. But putting up a barrier is not the only way. Sperm cells are good in both swimming and drilling. The most common birth control tool is the condom. Proper use of condom actually helps in targeting the swimming portion of the process of pregnancy thereby controlling the sperm cells. But recent discoveries have shown that scientists have been able to find a way to stop the sperm cells in the drilling task. The result would be an effective treatment that would work equally for both men and women.


The sperm cells travel at a high speed to the fallopian tube from the cervix through the uterus moving their tails side to side. It swims around 24000 times of their own length of their body to reach the egg. Now the egg is covered in a thirty-micron thick protective layer known as the zona pellucida which is impossible for the five micron long headed human sperm to penetrate.

The sperm cells then turn into a direction and corkscrewing their head forward pierces through the viscous outer layers of the egg. This process is termed as the " power kick" by the scientists which means a huge amount to calcium ions are dumped into the sperm's tail. A particular enzyme on the tails of these hyperactive sperms responds to progesterone, the female sex hormone, which helps in activation of the power kick which in turn boosts the swimming speed of the sperms. It is believed that progesterone affects the progression the sperms. Scientists in a recent development introduced small electrodes that were attached to the tails of the sperm cells to record their responses to various hormones.


The power kick banks upon the Catsper despite the presence of thousands of different kinds of ion channels. When the sperm gets close to the unfertilized egg the CatSper activates to let in the calcium and encounters the progesterone. Few chemical compounds bind with the CatSper and helps in prevention of the calcium ions dump required for the power kick. There are two most promising compounds that come from plants consumed by the humans - lupeol found in the mangoes, grapes etc.


The previous male contraceptives have either failed or dropped due to its side effects. This new discovery would make a compelling pitch for drug makers. However, vasalgel is an exception here. It is a gel like barrier used to block sperms. It has passed the primate trials and has shown positive results.