REPRODUCTIVE HEALTH AND THE WORKPLACE

Noise

Working in a noisy job when you’re pregnant can affect your hearing and increase your stress levels. When the noise level is very high, like a jackhammer or at a rock concert, it may increase your chances of having a baby with hearing problems. Here, you can learn more about noise at work and what you can do to reduce your exposure for a healthier pregnancy.

Why should I be concerned about noise?

• Increased noise levels can cause stress. This can cause changes in a pregnant woman’s body that can affect her developing baby.
• Sound can travel through your body and reach your baby. Although this sound will be muffled in the womb, very loud noises may still be able to damage your baby’s hearing.
• Hearing protectors (ear plugs or earmuffs) can protect your hearing, but if you’re pregnant the only way to protect your baby’s hearing is to stay away from the loud noise as much as possible.

Who works in noisy jobs?

Many women work in noisy jobs, especially women who work with machines, guns, loud music, crowds of people, sirens, trucks, or airplanes.

What is not known?

• We don’t always know what causes hearing problems in babies. If you work in a noisy job and have a baby with hearing problems, we may not be able to tell if the hearing problems were caused by your job or by something else.
• We don’t know for sure what levels of noise are safe for a pregnant woman and her baby, although experts have suggested guidelines based on what we know about how sounds travel through the body.

What can I do to reduce my hazardous noise exposure?

• Protect yourself from loud noise:
  • You should use hearing protection to protect your own hearing by wearing hearing protection (like ear plugs) if you are exposed to loud noise.
  • For adults, noise that is 85 decibels (dBA) or more can be hazardous to your hearing. At this noise level, you would have to raise your voice to be heard by someone next to you. Most workplace noise levels are less than 95 dBA.
  • While your hearing protection won’t protect your developing baby from loud noise, too much noise can cause you stress. Your stress can cause changes in your body that can affect your developing baby.
  • Ask your supervisor what the noise level is where you work.
• Protect your developing baby from very loud noise:
  • Your hearing protection will not fully protect your developing baby’s ears from noise. Noise travels through the body to the womb. A baby’s ears are mostly developed by about the 20th week of pregnancy, and babies start responding to sounds around the 24th week.
  • Sounds from outside the mother’s body are quieter inside the womb. Based on this, some experts think that pregnant women should not be routinely exposed to noise louder than 115 dBA. This is roughly as loud as operating a chainsaw. Areas that are very loud (more than 115 dBA) should be avoided during pregnancy as much as possible, even if you are wearing hearing protection.
• Noises that you can feel as a rumble or vibration are very low frequency sounds. We do not know for sure if developing babies are affected by this noise, but these sounds travel through your body easily and can cause changes in your body that could affect your developing baby. Avoid this kind of noise if possible.
• Sudden loud noises (impact or impulse noise) that are loud enough for you to need hearing protection or that startle you should be avoided during pregnancy.
• Sounds are stronger to your developing baby when your belly is closer to the source of the noise. Do not lean up against or put your body in contact with a source of noise. You should also avoid leaning against a source of vibration.
• It can be hard to avoid noise at work. Move as far away from the noise as possible or ask your employer if you can work in a quieter job during pregnancy.
• Talk to your doctor about all the potential hazards you have identified at work. Make sure to mention that you are exposed to loud noise.

Where can I get more information?

• Learn more about how noise can affect an unborn baby.
• Learn about sounds levels with the NIOSH Noise Meter.