Immunizations and Male Factor Infertility


When you’re trying to conceive, you inevitably start thinking about any and all past decisions that may be affecting your current fertility. These can include choices that you made concerning your diet and medications, as well as whether you smoke or drink alcohol. But can they also include receiving vaccinations? During National Immunization Awareness Month, we wanted to ask: can immunizations cause male factor infertility?


What is male factor infertility?

Infertility is generally defined as the inability to get pregnant after one year of having unprotected sex (or six months, if the woman is over 35). While many people may think of infertility as a primarily female-centered issue, the truth is that both men and women can be affected by infertility. In fact, according to the CDC, over one-third of all couples struggling with infertility have both male and female infertility factors present. Additionally, 8% of all infertile couples have male factors as the primary cause of infertility.

Unfortunately, due to the lingering social stigma surrounding male factor infertility, it can be difficult to find online support and resources for men that are affected by infertility. Generally, male factor infertility is attributed to one or more of these three factors:

  • Low sperm count—Your sperm count refers to the concentration of sperm in your semen. When less sperm is present in your semen, it decreases the probability that one of the sperm will make it through the female reproductive tract to fertilize an egg. A low sperm count is also called oligospermia.
  • Reduced sperm motility—Sperm motility is a term used to describe a sperm’s ability to actively move forward, or swim, through the female reproductive tract. Sperm that has weak or slow movement is less likely to reach and fertilize an egg. Poor sperm motility is also called asthenospermia.
  • Abnormal sperm morphology—Morphology refers to the size and shape of your sperm. Sperm with abnormal characteristics, such as an enlarged head or double tail will have a more difficult time reaching and fertilizing an egg.

Any of the above sperm characteristics can cause male factor infertility. Unfortunately, there are a variety of factors that can decrease sperm quality and quantity, such as sexually transmitted infections, exposure to endocrine disruptors, and hormone imbalances. Could immunizations also contribute to male factor infertility?


Can childhood vaccines cause male factor infertility?

Most children that grow up and attend public school or daycare in the United States receive a standard set of immunizations according to their age. The current recommended immunization schedule can be found on the CDC website. Chances are, you probably received most of the immunizations and vaccines listed on that schedule.

Note: Vaccination refers to receiving the vaccine dose, either orally or through an injection. Immunization refers to the effects of the vaccine on your body. After your immune system reacts to the vaccination it will be able to protect you from the virus in the future. This act of gaining immunity is referred to as immunization.

Immunizations that you may have received as a child include:


According to the CDC, potential side effects of these vaccines are rare and usually mild. These include tiredness, soreness or swelling at the injection site, headaches, and nausea. Severe allergic reactions to vaccines only occur in one out of every million doses administered. Most people experience no adverse effects after receiving immunizations.

Risks to future infertility and reproductive health are not listed among the possible side effects of any immunizations. On the other hand, becoming infected with one of these preventable communicable diseases could have a negative impact on your future fertility.

For example, HPV is typically thought of as a disease that only affects females. However, one study found that HPV-infected semen may cause infertility and early miscarriages. Another study noted that HPV-infected sperm can decrease the chances of success in assisted reproductive technology (ART) cycles.

Additionally, hepatitis B has been associated with decreased fertility in both men and women.

Because transmission of these diseases has the potential to decrease fertility, many physicians suggest some of the above vaccines for women who are trying to conceive. Other vaccines, such as the flu vaccine, are even recommended to women while they are pregnant.


Vaccines to consider while trying to conceive

If vaccines are recommended as a part of a woman’s health care while she is trying to conceive, should males consider being vaccinated as well? You should talk to your doctor if you are considering receiving any new immunizations—and you can always ask for a second opinion if you are left with any unanswered questions. Vaccinations may be recommended for couples who are trying to conceive as a way to protect both parents and the unborn child from preventable communicable diseases.

Before you know which vaccinations you may need, you will have to find your immunization records to see which diseases you have already been vaccinated against. These can usually be found in your school records or your medical history with any health care facility in which you may have received a vaccination. If you cannot find your immunization records, your physician may recommend repeating some vaccines or performing blood tests to determine whether you are immune to certain vaccine-preventable diseases.

Vaccines may also be recommended to guard against fever-causing viruses in males who are trying to conceive. This is important because a fever of 102 degrees or more over a period of at least three days can temporarily impact sperm production. In fact, one study found that men who had experienced a severe fever had impaired sperm concentration and motility for 3 to 6 weeks after the fever episode. It took 4 to 6 months for their sperm production to fully return to normal.

By receiving vaccinations for fever causing viruses, such as the flu, you can help protect your sperm health. Additionally, protecting yourself from vaccine-preventable diseases will keep you from transmitting those diseases to your partner while trying to conceive. Staying healthy is one of the best ways to help you and your partner improve your chances of getting pregnant.


Male preconception health tips

When you are experiencing male factor infertility, it can sometimes be challenging to find the exact cause. Fortunately, there are steps that you can take to improve your overall health and increase your sperm production and quality while trying to conceive.

In addition to staying up-to-date on all of your immunizations, there are other actions that your doctor will recommend to help improve your fertility and increase the chances of a healthy pregnancy. These can include:

When you make lifestyle changes such as the ones listed above, you can proactively increase your chances of conceiving. If you suspect that you may be experiencing male factor infertility, there are male fertility tests that may help you find the cause of your infertility. These tests can help you figure out whether medical treatment may improve your chances of conceiving.

The good news is that you don’t need to worry whether your childhood vaccinations might be affecting your current fertility. Instead, you can focus on lifestyle factors that you have the power to change. By having open discussions with your physician about what may be affecting your fertility, you can work together to figure out the best plan to help you and your partner get pregnant.


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