Pregnancy and Radiation Exposure

I am pregnant. What are the risks to my baby from dental, mammogram, chest, extremity, head, or CT exams that don't directly expose my abdomen?

The risks to the baby are minimal, if any, when x rays are taken of areas other than the abdomen. This is because the x-ray beam is focused only on the area of interest to minimize doses to other areas of the body. When you receive a diagnostic x-ray study of your head, teeth, chest, arms, or legs at a qualified facility, the x-ray exposure is not to your baby. The "scatter" radiation that might reach the baby would be extremely small and would not represent an increased risk for birth defects or miscarriage.

For some additional information, you can visit the Radiation Answers website.

How long should I wait to conceive after x-ray exams that have exposed my ovaries or my husband's testes? Can I become sterile after having x rays?

There is no evidence that there are any effects on the ovaries or sperm at doses used in diagnostic procedures such as the one(s) you had. If there were any risk at all, it would be very small. Also, this type of radiation does not remain in your body so that does not need to be a concern either.

How long should I wait to conceive after I have had/my spouse or partner has had radioiodine therapy?

The generally recommended waiting period prior to trying to conceive after radioiodine therapy varies from four to six months. A period of four months is discussed on page 15 of a 1997 report by the European Commission and a period of six months is discussed in a report from the International Commission on Radiological Protection (Publication 54).

What are the chances I am sterile after radioiodine therapy?

It is very unlikely that the ovaries or testes of a person who undergoes radioiodine therapy received enough radiation to render them sterile. In addition, the likelihood of next-generation biological effects is minimal.

I am pregnant. Is it okay to stand next to one of those airport baggage screening machines?

The x-ray machines at the airport are appropriately shielded. There is no increased risk to the operators or pregnant passengers for birth defects or miscarriage.

I was standing next to or holding the patient when the x ray was taken and I'm pregnant. What are the risks to my baby?

I understand your concern and will explain why your anxiety is not warranted in your present situation. When the person you were in the room with received the diagnostic x-ray study, the x-ray exposure was not to your baby. The "scatter" radiation that might have reached the baby would have been extremely small, if any, and would not represent an increased risk for birth defects or miscarriage. The most important characteristic of x rays that concerns us is the dose. Your developing baby did not receive a dose that would result in any measurable increased reproductive risk.

I am pregnant and want to have a procedure performed that involves the use of a laser. Can I do this without harming my baby?

There is no risk to the baby from the laser exposure. Laser beams barely penetrate the outer layers of skin when external to the body. The beam emitted from a laser is simply light in a different frequency from the type that lights our houses. The concern about laser surgery during pregnancy has to do with the anxiety and stress associated with the surgical procedure, and the anesthesia. Often laser procedures are not recommended for someone who is pregnant, not because of possible effect on the baby but because, during pregnancy with its associated hormonal changes, side effects of the procedure that the mother might encounter can be more severe.

I am pregnant and want to use a tanning bed. Any risks?

There is no evidence that radiation from a tanning bed would cause harm to the fetus. Lights in a tanning bed emit UVA or ultraviolet A radiation, similar to the tanning rays emitted by the sun although they are more concentrated in a tanning bed. UVA radiation is not very penetrating—clothes can stop it as you can tell by tan marks when you wear a T-shirt out on a sunny afternoon. UVA radiation is not able to penetrate through the skin and abdominal tissue to expose the fetus. There is no reason for concern.

I'm pregnant and plan on flying in the near future but am worried about possible risks to my baby.

Thank you for your question. Background radiation comes from cosmic rays, the earth, our own bodies, and medical care. You receive about 3 mSv from naturally occurring background radiation in the nine months of your pregnancy. Flying at 30,000 feet altitude increases your exposure a little bit from cosmic radiation but you reduce your exposure to radiation in the earth. The reproductive risks from commercial flying are so small that it is not measurable.

You can also refer to our information sheet on pregnancy and flying.

I might be exposed to radiation from a satellite dish at work. I am pregnant. Is it okay to continue working?

Satellite dishes for reception of cable television or microwave transmissions (for communication) do not emit any radiofrequency or electric and magnetic field (EMF) signals that would pose a health hazard to nearby persons.

You can also refer to our information sheet.

Occasionally I read that power lines cause biological effects and kids are especially at risk. I am pregnant and wonder what effect power lines might have on my baby.

The literature suggests there is no cause for concern. While most public concern about power-frequency fields (electromagnetic or EM radiation) has centered around cancer, there have also been suggestions that there might be a connection between nonionizing EM exposure and a variety of other human health problems.

Concern about miscarriages and birth defects has focused as much on video display terminals (VDTs) as on power lines. There is little epidemiologic or laboratory support for a connection between exposure to power-frequency fields and birth defects.

There are articles in the literature that have reviewed whether there is a link between prenatal EM exposure and biological effects. Huuskonen et al. (1998), Robert (1999), and Brent (1999) have reviewed this field in detail.

References
Huuskonen H. et al.: Teratogenic and reproductive effects of low-frequency magnetic fields. Mutat. Res. 410:167-183, 1998. 
"The epidemiologic evidence does not, taken as a whole, suggest strong associations between exposure to [power-frequency fields] magnetic fields and adverse reproductive outcome . . . Animal studies do not suggest strong effects on embryonal development or reproduction."

Robert E.: Intrauterine effects of electromagnetic fields-(low frequency, mid frequency RF, and microwaves): Review of epidemiologic studies. Teratology 59:292-298, 1999. 
"There is no convincing data that [electromagnetic field exposure] of the sort pregnant women or potential fathers meet in occupational or daily life exposures does any harm to the human reproductive process . . ."

Brent RL.: Reproductive and teratologic effects of low-frequency electromagnetic fields: A review of in vivo and in vitro studies using animal models. Teratology 59:261-286, 1999.
"Studies involving nonhuman mammalian organisms dealing with fetal growth, congenital malformations, embryonic loss and neurobehavioral development were predominantly negative and are therefore not supportive of the hypothesis that [power-frequency field] exposures result in reproductive toxicity."

For more information, visit the following website: Frequently Asked Questions (FAQs) on Power-Frequency Fields and Cancer or you can find additional information on this website.

I know we shouldn't leave food unattended while using a microwave oven but I am pregnant and don't know if it is safe for me to stand close to it while it is operating.

Current models of microwave ovens for domestic use are shielded to reduce microwave radiation levels to very small levels. Leakage from operating ovens is minimal. Because of the minimal radiation levels, there have been no reports of adverse pregnancy outcomes (i.e., ill effects in the newborn) as a result of microwave oven use. You can view additional information on microwave ovens at hps.org/hpspublications/articles/microwaveovens.html or a Q&A sheet at hps.org/publicinformation/ate/faqs/microwaveovenq&a.html.

I use my cell phone quite a bit for both personal and work reasons. Last week I found out I was pregnant and want to know if it is safe for me to continue using it.

A cell phone emits microwave electromagnetic (EM) radiation of moderate frequency, which is much different than the radiation of x rays. Furthermore, the amount of radiation is very small. This type of exposure does not put your fetus at risk for a measurable increased risk of birth defects.

We also have additional cell phone information on our website.

I am pregnant and my doctor has ordered an MRI exam to rule out some issues for back pain. Am I putting my baby at risk?

There is no evidence in the scientific literature that a standard diagnostic MRI (magnetic resonance image) performed on a person who is pregnant will cause fetal biological effects. The literature suggests that the strength of the MR field at diagnostic levels does not affect DNA synthesis, cell cycle, or proliferation kinetics in a fetus. The Food and Drug Administration (FDA) and other regulatory agencies have strict limits on MRI field strengths at diagnostic levels.

For more information, there is a bibliography of articles on MRI scans and biological effects available on the GE Healthcare website.

My coworkers and I work with computers all day. Some of my coworkers are pregnant and I wonder if there are any risks to their babies from radiation emitted from the computers.

Some older computers (built in the 1980s or before) emitted measurable amounts of nonionizing radiation-electric and magnetic fields. There was a flurry of activity after some publications in the late 1980s put it in headlines that workers might be exposed to more electric and magnetic field radiation than they should be. As a result, vendors reworked how the computers were built and, today, it would be much more difficult to find a computer (the monitor actually) that exposes the user to high amounts of electric or magnetic field radiation. You really should not be worried about using a computer because you are pregnant. We have a Q&A on computer emissions.

I am a female security guard who uses a portable radio for communication. We use our radios a lot. I am three months pregnant and am beginning to worry whether my using these radios is bad for my baby or not.

Although the devices of which you speak use radiofrequency energy (RF radiation), exposure of people working with these devices is normally very low. Devices such as these typically operate in what are called industrial, scientific, and medical frequency bands. These bands are assigned by the Federal Communications Commission to ensure that leakage from devices operating at these frequencies will not interfere with sensitive radio and navigation equipment. The ISM frequencies most commonly used in the United States for applications such as you describe are 13.56, 27.12, and 2450 MHz (megahertz).

Surveys of the RF leakage from devices demonstrates that the RF energy to which employees are exposed is far below the corresponding maximum permissible exposure values (MPE) for both occupational and exposure of the public. When RF fields can be found that approach the MPEs, it is usually only at isolated locations within a few centimeters (about an inch) of some portions of the equipment. Based on typical exposure patterns this is not considered hazardous.

Exposure to RF energy below the MPE is considered safe-not only for the healthy worker but for pregnant women and the fetus as well. The overwhelming weight of scientific evidence unequivocally demonstrates that biological effects associated with exposure to RF energy are threshold effects, i.e., unless the exposure level is sufficiently high an effect will not occur regardless of exposure duration. This is quite different from ionizing radiation, e.g., x rays and nuclear radiation. Unlike exposure to ionizing radiation, repeated exposures to low levels of RF energy (or nonionizing radiation) are not cumulative. Thus, it is relatively straightforward to derive safety limits. By adding safety factors to the threshold level at which the most sensitive reproducible effect occurs, conservative exposure guidelines have been developed to ensure safety.

If you wanted to do so, the exposure to personnel working with these devices can be measured with commercially available portable devices called broadband RF field-strength meters, survey meters, or hazard probes. These devices simultaneously measure the total RF field across the entire portion of the spectrum over which they are calibrated, e.g., 300 kHz to 6000 MHz or much higher. Depending on the manufacturer, e.g., Holaday Industries or Narda, the display reads in "RF Power Density," "Field Strength Squared," (either of which can be compared directly with the MPE if the source frequency is known) or "percent of the MPE." The readings represent the total combined RF environment at the point of measurement.