Many things can impact the ability to have healthy children for both women and men, including hazards in the workplace. Some workplace hazards can affect the ability to become pregnant, the health of unborn children, and child development. Many people don’t consider their job as a possible cause for reproductive problems, but they need to be aware of some issues. Whether you are considering having children now or not, reproductive hazards matter all the time, for both men and women.

Although workplace exposures can affect reproductive health, there are things you can do to better ensure your job does not hinder your ability to have a healthy family.

Where you work, how you work, and what you work with can affect your reproductive health or your family’s health.

• You can carry chemicals home on your skin, hair, clothes, and shoes. Some of these can harm the health of children and other people in your household.
• Many chemicals in the workplace haven’t been tested to see if they can cause reproductive problems.
• Laws for workplace safety and health don’t always protect your reproductive health and the health of your family.
• Men: Your sexual function, sperm, or semen can be affected by workplace hazards. Some chemicals can concentrate in semen.
• Women: If you are exposed to hazards at work and are pregnant or breast feeding, your baby can be exposed too.

Workplace hazards can lead to certain reproductive health problems, such as:

• Reduced fertility or infertility
• Erectile dysfunction
• Menstrual cycle and ovulatory disorders
• Women’s health problems linked to sex hormone imbalance
• Miscarriage
• Stillbirth
• Babies born too soon or too small
• Birth defects
• Child developmental disorders

What are reproductive hazards?

Reproductive hazards are substances that affect the reproductive health of men or women. They also include substances that affect the ability of couples to have healthy children. These substances may be chemical, physical, or biological. Some common types include

• Alcohol
• Chemicals such as pesticides
• Smoking
• Legal and illegal drugs
• Metals such as lead and mercury
• Radiation
• Some viruses

You may be exposed to reproductive hazards through contact with your skin, breathing them in, or swallowing them. This can happen anywhere, but it is more common in the workplace or at home.

What are the health effects of reproductive hazards?

The possible health effects of reproductive hazards include infertility, miscarriage, birth defects, and developmental disabilities in children. What type of health effects they cause and how serious they are depends on many factors, including

• What the substance is
• How much of it you are exposed to
• How it enters your body
• How long or how often you are exposed
• How you react to the substance

How can reproductive hazards affect men?

For a man, a reproductive hazard can affect the sperm. A hazard may cause a problem with the number of sperm, their shape, or the way that they swim. It could also damage the sperm's DNA. Then the sperm may not be able to fertilize an egg. Or it could cause problems with the development of the fetus.

How can reproductive hazards affect women?

For a woman, a reproductive hazard can disrupt the menstrual cycle. It can cause hormone imbalance, which can raise the risk of diseases such as osteoporosis, heart disease, and certain cancers. It can affect a woman's ability to get pregnant.

A woman who is exposed during pregnancy can have different effects, depending on when she was exposed. During the first 3 months of pregnancy, it might cause a birth defect or a miscarriage. During the last 6 months of pregnancy, it could slow the growth of the fetus, affect the development of its brain, or cause preterm labor.

How can reproductive hazards be avoided?

To try to avoid reproductive hazards,

• Avoid alcohol and illegal drugs during pregnancy
• If you smoke, try to quit. And if you are not a smoker, don't start
• Take precautions if you are using household chemicals or pesticides
• Use good hygiene, including handwashing
• If there are hazards at your job, make sure to follow safe work practices and procedures

If you work with chemicals, they can enter your body in three ways:

• Breathing the chemical in
• Coming in contact with the skin, especially if your skin is chapped, irritated, or if you have an open wound
• Hand-to-mouth

Chemical exposures can cause health problems. Whether or not they cause health problems depends on:

• What the chemical is
• How the chemical enters the body
• How long or how often a person is exposed to the chemical
• How each person reacts to the chemical

Chemicals aren’t the only hazards at work

Some job exposures are not chemicals, but they may still affect your reproductive health. Some examples of these exposures are:

• Radiation
• Loud noise
• Long working hours, shiftwork, or irregular work schedules
• Lifting, bending, and standing

What you should consider

Answer these questions to start thinking about your workplace exposures:

• What do you do in your job? What does your department or group do or make?
• What are you concerned about in your workplace? Any information on product name, actual chemical name, or work condition would be helpful.
• For chemicals, what form are the chemicals in: dust, vapor, liquid, gas?
• How much time do you spend using each thing that you are concerned about in your workplace?
• Do you use any personal protective equipment or other safety equipment while performing your job?

Many things can affect women’s reproductive health, their ability to have children, and the health of their children. Some of these factors are well-known, such as diet, smoking and drinking alcohol. However, little is known about what causes most female reproductive health problems such as infertility, miscarriage, and birth defects.

We know that some workplace hazards can affect reproductive health, the ability to become pregnant, and the health of unborn children. This section focuses on work-related reproductive hazards that affect women’s reproductive health and ability to have children.

To understand how reproductive hazards can affect your reproductive health and ability to have healthy children, it is helpful to understand how the female reproductive system works. Reproductive hazards in the workplace act on the tissues, eggs, and hormones that comprise the intricate female reproductive system.

By knowing how the reproductive system works, you can better protect yourself and your family against hazards, better understand your doctor, what you read, and media reports about reproductive hazards.

The female reproductive tissues

The main reproductive tissues in women are the ovaries, uterus, and fallopian tubes. These tissues are primarily controlled by hormones produced by the brain, the pituitary gland and the ovaries. These hormones also control:

• Menstrual cycles
• Pregnancy
• Breast milk production

Why hormones are important

Female sex hormones called estrogen and progesterone are produced by the ovaries. These hormones are responsible for sexual development and for preparing the uterine wall every month to hold and nourish a fertilized egg during pregnancy. These hormones also contribute to the health of the heart, bones, liver, brain and many other tissues. So, a reproductive hazard that alters your estrogen and progesterone production can also reduce your general health.

About the menstrual cycle

• As girls go through puberty, they begin to have periods (menstruation) and menstrual cycles.
• Each menstrual cycle begins with a few days of menstrual flow. When each new cycle begins, a few new eggs begin to grow in the ovaries.
• After about 2 to 3 weeks, one egg – occasionally more – matures to be released from the ovary (ovulation) into the fallopian tubes, where it might be fertilized by one of the many sperm that may surround it.
• If the egg is not fertilized, it will die and leave the body about 2 weeks later in the woman’s menstrual flow. Then the process begins again with a new menstrual cycle, a new period, and a new crop of growing eggs.
• Women are born with all of the eggs they will ever have. Eggs that are damaged or destroyed cannot be replaced.

What happens when an egg is fertilized

• If the egg is fertilized, the complex process of reproduction continues. The fertilized egg travels for about a week down the fallopian tube to reach the uterus, where it attaches to the uterine wall (endometrium).
• A specialized tissue called the placenta forms between the uterus and the newly developing baby. The placenta transfers oxygen and nutrients from the mother to her baby.
• During the first 3 months of pregnancy (first trimester), the baby’s major organs are formed.
• During the remainder of the pregnancy, these organs mature and the baby grows rapidly.

Due to the nature of the female reproductive system, exposures that may impact your fertility, may also impact your health in general.

The female reproductive system can be divided into the reproductive health of the woman and the wellbeing of her pregnancy and baby. This section addresses the reproductive health of the woman, herself. We address how a woman’s job can affect pregnancy, breastfeeding and family health elsewhere.

Female health problems that may be caused by workplace reproductive hazards

• Disruption of the menstrual cycle and hormone production

  High levels of physical or emotional stress or exposure to chemicals such as pesticides, polychlorinated biphenyls (PCBs), organic solvents and carbon disulfide, may disrupt the balance between the brain, pituitary gland, and ovaries. This disruption can result in an imbalance of estrogen and progesterone, and lead to changes in menstrual cycle length and regularity and ovulation.

• Infertility and subfertility

  About 10% to 15% of all couples are infertile or have subfertility, which means that they are unable to conceive a child after 1 year of trying to become pregnant. Many factors can affect fertility, and these factors can affect one or both partners. More common causes of infertility include:

  • Damage to the woman’s eggs
  • Damage to the man’s sperm
  • A change in the hormones needed to regulate the normal menstrual cycle and uterine growth

• Other health problems

  Even if you are not concerned about having menstrual cycles or are not trying to get pregnant, your general health can be harmed by reproductive hazards that alter the production of your sex hormones. These sex hormones have effects throughout a woman’s body. Some workplace exposures can cause an imbalance of estrogen and progesterone levels in your blood. This disruption can also leave you more vulnerable to:

  • Some cancers, such as endometrial or breast cancer
  • Osteoporosis
  • Heart disease
  • Tissue loss or weakening
  • Effects on the brain and spinal cord, including symptoms of menopause

Reproductive effects can vary among female workers

Reproductive hazards do not affect every woman or every pregnancy. Whether you are affected and the degree to which you or your baby may be harmed depends on different factors:

• The type of hazard
• How long you are exposed
• How much of the hazard you are exposed to
• How you are exposed
• Personal factors, like your age, stage of menstrual cycle, stage of pregnancy or when you are exposed

For example, exposure to a hazard could block ovulation and pregnancy only at specific times of the menstrual cycle. Exposure during the first 3 months of pregnancy might cause a birth defect or a miscarriage. Exposure during the last 6 months of pregnancy could slow the baby’s growth, affect its brain development, or cause premature labor.

Though there is no complete list of reproductive hazards in the workplace, a number of workplace substances have been identified as reproductive hazards for men. Reproductive hazards are substances that affect the ability to have healthy children. Learn more about specific exposures found to have reproductive effects in men and how you can lower your exposures.

Some examples of reproductive hazards include:

• Radiation
• Pesticides
• Various chemicals and solvents
• Legal and illegal drugs
• Cigarettes
• Heat

Scientists are just beginning to understand how reproductive hazards affect the male reproductive system. Although more than 1,000 workplace chemicals have been shown to have reproductive effects on animals, most have not been studied in humans. There are over 72 million unique chemicals registered by the American Chemical Society, with about 15,000 new substances added every day, most of which are not tested for reproductive health effects.

Reproductive Health Problems Potentially Associated with Workplace Exposures

The Table below shows examples of reproductive hazards for men in the workplace. Although studies have found that workplace exposures may affect the reproductive system in some men, these effects do not necessarily occur in every worker. Some of the agents listed in the Table are well-known reproductive hazards (such as lead), while the scientific evidence for the others may not be as definitive.

Whether or not an exposure will cause a reproductive problem depends on:

• The amount of time you’re exposed
• The amount of the hazard you’re exposed to
• How you were exposed.
• How your body reacts to the hazard

These are only examples of hazards. Do not assume that a substance is safe if it is missing from the table.

Table – Examples of Potential Reproductive Hazards

Can You Expose Your Family to Workplace Hazards?

Your family may never come to your workplace but could be exposed to hazards in your workplace that you may accidentally bring home. This could affect your partner’s health, the health of a pregnancy or your children. Many chemicals can be carried to your car or to your home on your skin, hair, clothes, shoes or tool box exposing others in the family. Some infections, including Zika virus, can be passed to sexual partners.

Scientists are just now beginning to understand how reproductive hazards affect the female reproductive system. Though most workplace chemicals have not been studied for reproductive effects, there are some known workplace exposures you should be aware of.

Female reproductive hazards can be chemical, physical or other workplace conditions that affect the reproductive health of women and their ability to become pregnant. Your exposure to something hazardous at work does not mean that you will have these health problems. Though studies have found some workplace hazards can affect the reproductive system in women, these effects do not necessarily occur in every worker.

Please remember:

• This list is not a complete and it is constantly being revised.
• Do not assume a substance is safe if it is missing from the list.
• You may or may not experience these health problems after being exposed to hazards at work.

Hazards that can reduce fertility in women

• cancer treatment drugs, including antineoplastic drugs
• lead
• ionizing radiation, including x-rays and gamma rays
• nitrous oxide (N2O)

Hazards that can disrupt the menstrual cycle and/or sex hormone production

• a variety of pesticides
• carbon disulfide (CS2)
• polychlorinated biphenyls (PCBs)
• organic solvents
• jet fuel
• shift work

There are also job exposures that are, or may be, hazardous to a baby during pregnancy or while breast feeding. Learn more about these exposures, including infectious agents that can be harmful to the outcome of pregnancies.

Some jobs can affect your reproductive health and the health of your family. Reproductive hazards affect both men and women. Even if your job involves some hazards, there are things you can do to protect yourself and stay safe at work:

1. Ask questions

By law, you have the right to receive information on hazards in your workplace and to receive training on how to stay safe.

• Ask your employer or your company’s safety officer about the types of hazards for your specific job tasks and how you can stay safe while doing your job.
• If the company has done testing to identify workplace hazards (e.g., measuring chemicals in the air), your employer is required to give you a copy of the results if you ask for them.
• If you work with chemicals, your employer should have Safety Data Sheets (also called Material Safety Data Sheets or (MSDS) available for all employees to read.

2. Protect yourself from exposure

• Use personal protective equipment (PPE) correctly
  If your employer gives you PPE such as gloves, hearing protection, or a respirator, make sure you are using it consistently and correctly. Remember to check your PPE before using it to make sure it is functioning properly. Talk to your employer or safety officer if you have questions about how to use your PPE. Learn more about PPE use and reproductive health.
• Follow best safety and health practices
  Learn about best work practices for health and safety, like always keeping chemicals in sealed containers when not in use. Follow any safe work guidelines or protocols in your workplace, even if your tasks take a little longer. If your employer offers health and safety training, take part. You can also find more information on workplace health and safety topics from NIOSH.
• Wash it off
  If your work involves coming into contact with chemicals, avoid skin contact and remember to wash your hands before eating and before leaving work.

3. Talk to your doctor or health care professional

Not all doctors or healthcare professionals remember to ask you about your job. If you are concerned about your health, or if you and your partner are pregnant or trying to become pregnant, tell your doctor:

• What kind of work you do
• What kinds of hazards are in your workplace (e.g., chemicals, noise, heat, working night shifts, lifting heavy objects)
• If there is anything specific you are worried about or have questions about.

Ask your healthcare professional if there is any part of your job you should be avoiding during pregnancy or breastfeeding.

4. Protect your home and family

Are you accidentally bringing work hazards home with you? Chemicals can come home on your skin, hair, clothes, and shoes, and they can contaminate your car and home. Keep a healthy car and home by changing clothes and showering before leaving work, keeping work clothes out of the living areas of the house, and washing work clothes in separate laundry loads from the family’s clothes.

5. Request a Health Hazard Evaluation

If you think your job is affecting your health or the health of your family, NIOSH can help. A Health Hazard Evaluation (HHE) is a free service from NIOSH that will give you or your employer advice about what kinds of health hazards might be in your workplace and how to make your workplace safer.