Recurrent Miscarriage: May be linked to the poor quality of sperm

Sperm Damage may provide clues to Recurrent Miscarriage.
Oxidative stress and DNA damage in sperm may contribute to repeated miscarriages in female partners.

There is strong understanding of female factors that can contribute to recurrent pregnancy loss, but male factors that may play a role is far less known. Recurrent pregnancy loss — at least three consecutive miscarriages (before 20 weeks' gestation) — occurs in about 1-2% of couples, and about half of cases are unexplained. A lot of women undergo many tests to determine the cause, but many cases have no identified cause. 

It is important to know the medical history of male partners, examine them, and maybe offer a further investigation so that it can be established where the problem is, and perhaps offer the couple better treatment.

The role of the sperm

The sperm plays an important role in the formation of the placenta, which is critical for survival of an unborn baby. Some known risk factors for male infertility include genitourinary infection, varicocele, scrotal heat, and obesity. Some of these conditions might contribute to reactive oxygen species in semen, which could then cause sperm DNA fragmentation and subsequent pregnancy loss.

Frances Hayes, MBBCh, clinical director of the reproductive endocrine unit at Massachusetts General Hospital, Boston therefore has a take-home message; "Don't neglect the male. Sometimes there may be need to screen both potential parents for balanced translocation in the chromosomes, but most of the focus is typically on the woman."

 

The early-stage study, from scientists at Imperial College London, investigated the sperm quality of 50 men whose partners had suffered three or more consecutive miscarriages.

The research, revealed that, compared to men whose partners had not experienced miscarriages, the sperm of those involved in the study had higher levels of DNA damage.

Until recently recurrent miscarriage was thought to be caused by health issues with the mother, such as infection or immune problems.

"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."

The research team is now investigating what may trigger high levels of these reactive oxygen species. It is possible there may be bacteria from previous infections lingering in the prostate gland, which makes semen. This may lead to permanently high levels of reactive oxygen species.

Obesity can lower sperm health as well -- possibly because high levels of body fat can trigger an increase in reactive oxygen species.

Dr Channa Jayasena, lead author of the research from Imperial's Department of Medicine concludes: "It has taken medicine a long time to realise sperm health has a role to play in miscarriage -- and that the cause doesn't lie solely with women. Now we realise 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."