Medically Reviewed by Dr. Norbert Gleicher, MD, FACOG, FACS

Having a miscarriage sucks. Having recurring miscarriages can be frustrating and devastating. There are various reasons why a miscarriage might occur, but new research continues to reinforce the connection between recurrent miscarriage and low sperm quality.

A new 2019 study published in the journal Clinical Chemistry finds a connection between women with recurrent pregnancy loss, or RPL, and poor sperm quality in their male partners. RPL is defined as the loss of three or more consecutive pregnancies before 20 weeks of gestation and, according to the study, affects 1 to 2% of couples.

Women who experience RPL are regularly tested for conditions like thrombophilia, which is an increased tendency to form blood clots, or the autoimmune disorder known as antiphospholipid syndrome (APS). Both these conditions are diagnosed through blood testing. However, approximately 50% of RPL cases have no identifiable cause.

Previous studies in the space suggested that sperm quality is reduced in male partners of women with RPL, but the reasons were unclear. This 2019 study is the first step into further research in this field.

Results of this 2019 study showed total sperm motility (how well sperm swim), progressive sperm motility (the ability for sperm to swim straight), and normal morphology (the size and shape of the sperm) were all reduced vs the control group.

Their findings showed male partners of women with RPL have:

• Impaired reproductive endocrine function

Your endocrine system is the collection of glands that produce hormones that regulate metabolism, growth and development, tissue function, sexual function, reproduction, sleep, and mood, among other things.  Impaired reproductive endocrine function means your reproductive glands (the testes in the male) produce too much or too little of a specific sex-related hormone.

In this study, the mean ±SE morning serum testosterone (primary male sex hormone) was 15% lower in RPL group than in the control group.  The mean ±SE serum estradiol (primary female sex hormone – important for men too) was 16% lower.  These male hormonal imbalances can lead to inadequate sperm production among other implications.  Without adequate sperm production, the production of a healthy, fertilized egg may not be possible or the quality of the fertilized egg may be impacted and it may not implant into the uterus.

Impaired reproductive endocrine function in males may manifest as loss of libido, impotence, and infertility.  Blood and urine tests to check your hormone levels can help your doctors determine if you have impaired reproductive endocrine function.

You can start to heal your endocrine system through nutrition. Check out these 12 Natural Ways to Balance Your Hormones.

• Increased levels of semen ROS

 Your body works on a series of chemical reactions.  Glucose (our fuel found in food) is combined with oxygen to create energy, or ATP.  This reaction happens in the cell’s “engine”, the mitochondria.  The byproducts of this reaction are Carbon Dioxide, water and free radicals.   These free radicals (known as reactive oxygen species, or ROS) cause damage to cells in a process known as Oxidative Stress.  Essentially, this causes your body’s cells to rust.

This study found the mean ROS was 4x higher in the RPL group than in the control group.

How can you minimize the effect of ROS?  The best way to reduce the effects of ROS is to eat a diet high in antioxidant foods including:

• Dark Chocolate
• Blueberries
• Cranberries
• Blackberries
• Kidney beans
• Artichokes
• Cilantro

You can also take a high-quality antioxidant supplement designed for fertility.

• Sperm DNA fragmentation (SDF)

The genetic material in the sperm must be complete and high-quality in order for the sperm to successfully fertilize an egg and for normal embryo development to occur.  Sperm DNA fragmentation is abnormal genetic material within the sperm, which has been shown in studies to lead to male subfertility, IVF failure and miscarriage.  In this study, the mean DNA fragmentation in the RPL group was 2x higher than in the control group.

A 2018 study by Gi Young Kim examined treatments for sperm DNA fragmentation and found that males with a high level of SDF should aim to decrease SDF through lifestyle modifications and antioxidant treatment.

• Lifestyle modifications:
  • The 2018 study shows that lifestyle modifications are the most fundamental, important, simple, and easy way to improve sperm quality. Men with impaired sperm quality should consider:
    • Quitting smoking and drinking
    • Engaging in exercise to manage their weight
    • Wearing loose underwear
    • Avoiding environments with high temperatures such as saunas, lower-body bathing, and high temperature workspaces
    • Abstaining from ejaculation for an appropriate duration

• Oral antioxidant therapy
  • Imamovic Kumalic and Pinter conducted a meta-analysis of 32 studies published between 2000 and 2013 related to male infertility and antioxidants and found “vitamin E, vitamin C, selenium, coenzyme Q10, N-acetylcysteine, zinc, and L-carnitine to be effective at reducing oxidative stress” in males.

The 2019 study recommends routine male reproductive assessments may be beneficial in RPL. It takes approximately 64 days for men to create new sperm.  You may want to consider continuing to have your partner’s sperm tested throughout your reproductive journey if you have had multiple pregnancy losses.