A recent study published in the journal Molecular and Cellular Proteomics, refute the widespread belief that abstinence between attempts to get pregnant improves the couple’s chance of success. The research team of the Center for reproductive medicine hospital of shengjing ancient (Center for Reproductive Medicine of Shengjing Hospital) the Chinese city of Shenyang to test this hypothesis, worked with 500 couples.
For many years, men are usually encouraged to restrict sexual activity to increase the chances of pregnancy. However, it is time to reconsider, says one of the researchers, Dr. Da Li (Da Li).
Some studies showed that sperm obtained soon after a previous ejaculation (within approximately three hours) faster and more motile sperm than abstaining in a few days. But it is not clear why the sperm is changing and the influence of these changes on fertility. Therefore, the researchers conducted multiple experiments.
They examined the sperm after abstinence for several days and after an hour-two hours after the previous ejaculation, when comparing the volume of sperm and sperm motility. As mentioned earlier, the sperm in the sperm from the shorter periods of abstinence were more mobile.
Using mass spectrometry to study protein composition of the samples, the team discovered some key molecular differences. Most of the altered proteins were involved in cellular adhesion (a function required for merge of the sperm with the egg).
Observed changes in the proteins involved in the motility and metabolism of sperm cells, especially in proteins that regulate the formation of active forms of oxygen (a byproduct of cellular energy production), excess of which can damage the genetic material of the sperm. According to the results, the sperm prolonged abstinence are more vulnerable to DNA damage by active oxygen.
To find out, does change sperm fertility, also conducted a study of 500 couples preparing for in vitro fertilization at the clinic. Men in the control group gave semen samples after several days of abstinence, whereas in the experimental group after three hours of abstinence.
Typical fertility rate in the cohort of this size is about 30 percent. In the experimental cohort of live births was more than one-third, says Yes If.
Now scientists suggest that couples with relatively normal semen parameters to have frequent sex during the ovulation period. This greatly increases the chance of conception.
The research team plans to continue working with patients and to study differences in posttranslational modifications observed between the two types of samples. While this is a completely new but very promising field.