In a study, scientists from Imperial College studied the quality of sperm of the 50 men whose partners experienced three or more miscarriages in a row. The findings are published in the journal Clinical Chemistry. The study compared the men whose partners had miscarriages and the men whose partners did not have any miscarriage. The study concluded that the miscarriages were due to faulty sperms and a higher level of DNA damage in them.
The team hoped that the study will pave a path for new treatments to reduce the cases reported regarding miscarriages. Around 1 out of 50 couples report of having recurrent miscarriages in the UK. A recurrent miscarriage in simple words is defined as losing three or more pregnancies in a row before 20 weeks of pregnancy.
Previously, it was commonly thought that recurrent miscarriages were a result of maternal health issues such as severe infection or immune problem. Now doctors realize, sperms health also play an important role in pregnancies.
A lead author, Dr. Channa Jayasena of the research from Imperial’s Department of Medicine said: “Traditionally doctors have focused attention on women when looking for the causes of recurrent miscarriage. The men’s health—and the health of their sperm wasn’t analyzed.
“However, this research adds to a growing body of evidence that suggests sperm health dictates the health of a pregnancy. For instance, previous research suggests sperm has an important role in the formation of the placenta, which is crucial for oxygen and nutrient supply to the fetus.” In the study, the scientists observed the sperms of 50 men who were the victims of recurrent miscarriages at St Mary’s Hospital in London, part of Imperial College Healthcare NHS Trust.
After analyzing the sperms of those 50 men, the researchers compared the results with the sperms of 60 men whose partners did not experience any miscarriage. The comparative result showed that the sperms of the men whose partners went through miscarriages had DNA damage twice to the comparative group. According to the team, this DNA damage in the sperm is due to reactive oxygen species.
Reactive oxygen species are the molecules produced in the fluid (semen) of men to shield and safe the sperms from bacteria and other pathogenetic organisms. However, these same molecules can cause potential damage to the sperm cells if they are formed in high concentration.
The analysis revealed that sperms of men whose partners experienced recurrent miscarriages had four times the reactive oxygen species than the comparative group.
Now the researchers are eager to learn about the cause behind these abnormal levels of reactive oxygen species in sperms. Dr. Jayasena described it by saying: “Although none of the men in the trial had any ongoing infection such as Chlamydia – which we know can affect sperm health – it is possible there may be other bacteria from previous infections lingering in the prostate gland, which makes semen. This may lead to permanently high levels of reactive oxygen species.”
One of the possible risk factors of poor sperm health is obesity as the increasing evidence supports the link between the high amount of body fat and increase levels of reactive oxygen species. Thus, the study team is now investigating the metabolic health of 50 men including their weight and cholesterol levels.
In the study, men whose partners went through recurrent miscarriages were slightly older than the control group plus they were also overweight. Now the team is working on these factors in order to know how they influence the levels of reactive oxygen species in sperms.
According to Dr. Jayasena, “Although this is a small study, it gives us clues to follow. If we confirm in further work that high levels of reactive oxygen species in semen increase the risk of miscarriage, we could try to develop treatments that lower these levels and increase the chance of a healthy pregnancy.
“It has taken medicine a long time to realize sperm health has a role to play in miscarriage – and that the cause doesn’t lie solely with women. Now we realize both partners contribute to recurrent miscarriage, we can hopefully get a clearer picture of the problem and start to look for ways of ensuring more pregnancies result in a healthy baby.”