This sheet is about exposure to azithromycin in pregnancy and while breastfeeding. This information is based on published research studies. It should not take the place of medical care and advice from your healthcare providers. 

What is azithromycin?

Azithromycin is an antibiotic that has been used to treat many bacterial infections, including lung infections (such as bronchitis and pneumonia), strep throat, and ear, sinus, and skin infections. It is also commonly used, including during pregnancy, to treat infections such as malaria, mycoplasma, and chlamydia. Brand names include Z-Pak®, Zithromax®, and Zmax®. 

For more information on malaria, see our fact sheet at https://mothertobaby.org/fact-sheets/malaria/.  

Sometimes when women find out they are pregnant, they think about changing how they take their medication, or stopping their medication altogether. However, it is important to talk with your healthcare providers before making any changes to how you take your medication. Your healthcare providers can talk with you about the benefits of treating your condition and the risks of untreated illness during pregnancy. 

I take azithromycin. Can it make it harder for me to get pregnant?

It is not known if taking azithromycin can make it harder to get pregnant.  

Does taking azithromycin increase the chance of miscarriage?

Miscarriage is common and can occur in any pregnancy for many different reasons. Most studies on azithromycin and similar antibiotics have not reported an increased chance of miscarriage.  

Does taking azithromycin increase the chance of birth defects? 

Birth defects can happen in any pregnancy for different reasons. Out of all babies born each year, about 3 out of 100 (3%) will have a birth defect. We look at research studies to try to understand if an exposure, like azithromycin, might increase the chance of birth defects in a pregnancy. 

A few studies have suggested azithromycin might increase the chance of some birth defects. However, most studies have not found an increased chance of birth defects when azithromycin is used during pregnancy. 

Does taking azithromycin in pregnancy increase the chance of other pregnancy-related problems?

Azithromycin is not expected to increase the chance of other pregnancy-related problems, such as preterm delivery (birth before week 37) or low birth weight (weighing less than 5 pounds, 8 ounces [2500 grams] at birth). 

Does taking azithromycin in pregnancy affect future behavior or learning for the child?

One study looking at over 8,000 children exposed to azithromycin or other antibiotics like azithromycin during pregnancy found no significant increased chance of attention deficit hyperactivity disorder (ADHD) or autism spectrum disorder.  

Breastfeeding while taking azithromycin:

Azithromycin passes into breast milk in small amounts. The amount of azithromycin that gets into breast milk is lower than what would be given to a child to treat an infection. Short term use of azithromycin is generally considered compatible with breastfeeding.  

There are some studies that suggest that the chance of pyloric stenosis (a condition where the muscles of the pylorus [the valve between the stomach and small intestine], get thicker and narrower, making it hard for food to pass through) might be increased when azithromycin is taken during the first two weeks of breastfeeding. Other studies have not reported an increased chance of pyloric stenosis. Overall, there is not enough information to determine if breastfeeding while taking azithromycin can increase the chance of pyloric stenosis.  

Children who are exposed to azithromycin or other antibiotics through breast milk might have diarrhea or develop thrush (fungal infection of the mouth). If you suspect that your baby has symptoms such as forceful vomiting, weight loss, fussiness, lethargy, and signs of dehydration such as fewer wet diapers, contact your baby’s healthcare provider. Be sure to talk to your healthcare provider about all your breastfeeding questions.  

If a man takes azithromycin, could it affect his fertility or increase the chance of birth defects?

Studies have not been done to see if azithromycin could affect men’s fertility (ability to make healthy sperm) or increase the chance of birth defects. In general, exposures that fathers or sperm donors have are unlikely to increase risks to a pregnancy. For more information, please see the MotherToBaby fact sheet Paternal Exposures at https://mothertobaby.org/fact-sheets/paternal-exposures-pregnancy/.  

Please click here for references.  

This sheet is about exposure to meclizine in pregnancy and while breastfeeding. This information is based on published research studies. It should not take the place of medical care and advice from your healthcare provider.  

What is meclizine? 

Meclizine is a medication that has been used to treat nausea and vomiting, motion sickness, and vertigo (a feeling of whirling and loss of balance). It belongs to a class of medications called antihistamines. Meclizine is available over the counter and by prescription. Some brand names for meclizine are AntivertÒ, BonineÒ, MeclicotÒ, and DramamineÒ.   

Sometimes when women find out they are pregnant, they think about changing how they take their medication, or stopping their medication altogether. However, it is important to talk with your healthcare providers before making any changes to how you take your medication. Your healthcare providers can talk with you about the benefits of treating your condition and the risks of untreated illness during pregnancy. MotherToBaby has a fact sheet on nausea and vomiting in pregnancy here https://mothertobaby.org/fact-sheets/nausea-vomiting-pregnancy-nvp/. 

I take meclizine. Can it make it harder for me to get pregnant? 

Studies have not been done to see if taking meclizine can make it harder to get pregnant. 

Does taking meclizine increase the chance of miscarriage?   

Miscarriage is common and can occur in any pregnancy for many different reasons. When used as directed, meclizine is not expected to increase the chance of miscarriage.  

Does taking meclizine increase the chance of birth defects? 

Birth defects can happen in any pregnancy for different reasons. Out of all babies born each year, about 3 out of 100 (3%) will have a birth defect. We look at research studies to try to understand if an exposure, like meclizine, might increase the chance of birth defects in a pregnancy. Most studies do not suggest an increase in birth defects with use of meclizine during the first trimester. This includes a large looking at over 16,000 pregnancies exposed to meclizine in the first trimester.  

Does taking meclizine in pregnancy increase the chance of other pregnancy-related problems?  

It is not known if meclizine can increase the chance of other pregnancy-related problems, such as preterm delivery (birth before week 37) or low birth weight (weighing less than 5 pounds, 8 ounces [2500 grams] at birth). One large study looking at over 16,000 pregnancies exposed to meclizine in the first trimester found no increased chance of preterm birth, low birth weight, short body length, and small head circumference after exposure to meclizine. 

Does taking meclizine in pregnancy affect future behavior or learning for the child?   

It is not known if meclizine increases the chance for behavior or learning issues for the child.  

Breastfeeding while taking meclizine:   

There is no information on meclizine use while breastfeeding. If you suspect that the baby has symptoms (such as drowsiness, irritability, or dry mouth), contact the child’s healthcare provider.  

It is possible, but not proven, that antihistamines might lower the amount of breast milk a person makes. This might be more likely to happen if antihistamines are used together with an oral decongestant like pseudoephedrine (Sudafedâ), or if used before breastfeeding is fully established (when a baby is first born). Be sure to talk to your healthcare provider about all your breastfeeding questions.  

If a man takes meclizine, could it affect fertility or increase the chance of birth defects? 

Studies have not been done to see if meclizine could affect men’s fertility (ability to get a partner pregnant) or increase the chance of birth defects. In general, exposures that fathers or sperm donors have are unlikely to increase risks to a pregnancy. For more information, please see the MotherToBaby fact sheet Paternal Exposures at https://mothertobaby.org/fact-sheets/paternal-exposures-pregnancy/. 

Please click here for references.

This sheet is about exposure to spironolactone in pregnancy and while breastfeeding. This information is based on published research studies. It should not take the place of medical care and advice from your healthcare provider. 

What is spironolactone?

Spironolactone is a potassium-sparing diuretic (commonly called water pills) that has been used to treat swelling, congestive heart failure, primary hyperaldosteronism (when the adrenal glands make too much of the hormone aldosterone), and hypertension (high blood pressure).) It has also been used to treat acne, hair loss in women, and hirsutism (increased growth of facial and body hair growth). Some brand names for spironolactone are Aldactone®, Carospir®, and Qaialdo®. 

Sometimes when women find out they are pregnant, they think about changing how they take their medication, or stopping their medication altogether. However, it is important to talk with your healthcare providers before making any changes to how you take your medication. Your healthcare providers can talk with you about the benefits of treating your condition and the risks of untreated illness during pregnancy. 

One product label for spironolactone recommends women who are pregnant not use this medication during pregnancy. Other product labels suggest using this medication if the benefits outweigh the potential risks. Your healthcare provider can talk with you about using spironolactone and what treatment is best for you. 

I am taking spironolactone, but I would like to stop taking it before getting pregnant. How long does the drug stay in my body?

The time it takes the body to process or break down (metabolize) the medication is not the same for everyone. In healthy, non-pregnant adults, it takes up to 12 hours, on average, for most of the spironolactone to be gone from the body. The time it takes for the metabolites (break-down products) of spironolactone to be gone from the body can be up to 100 hours (about 4.5 days).  

I take spironolactone. Can it make it harder for me to get pregnant? 

Studies have not been done in women to see if taking spironolactone can make it harder to get pregnant. Spironolactone can cause changes in the menstrual cycle (period), delay puberty, and delay ovulation (when an ovary releases an egg), which might make it harder to get pregnant.  

Does taking spironolactone increase the chance of miscarriage? 

Miscarriage is common and can occur in any pregnancy for many different reasons. Available information does not suggest that taking spironolactone can increase the chance of miscarriage.  

Does taking spironolactone increase the chance of birth defects? 

Birth defects can happen in any pregnancy for different reasons. Out of all babies born each year, about 3 out of 100 (3%) will have a birth defect. We look at research studies to try to understand if an exposure, like spironolactone, might increase the chance of birth defects in a pregnancy. 

It is not known if taking spironolactone can increase the chance of birth defects. Information from animal studies suggests that taking spironolactone early in pregnancy might increase the chance of feminization (when a male develops female sex characteristics) in the offspring. However, it is not known if this will happen in human pregnancy. There are case reports of women taking spironolactone during pregnancy who gave birth to children without birth defects or decreased virilization (less male sex characteristics) noted.  

Does taking spironolactone in pregnancy increase the chance of other pregnancy-related problems?

It is not known if spironolactone can increase the chance of other pregnancy-related problems, such as preterm delivery (birth before week 37) or low birth weight (weighing less than 5 pounds, 8 ounces [2500 grams] at birth). Some of the conditions spironolactone is used to treat can increase the chance of pregnancy-related problems.  

Does taking spironolactone in pregnancy affect future behavior or learning for the child?  

Studies have not been done to see if spironolactone can increase the chance of behavior or learning issues for the child.  

Breastfeeding while taking spironolactone:

Spironolactone passes into breast milk in small amounts. These amounts are not expected to cause side effects in most nursing infants. If you suspect the baby has any symptoms (such as drowsiness or trouble feeding), contact the child’s healthcare provider. Be sure to talk to your healthcare provider about all your breastfeeding questions.  

If a man takes spironolactone, could it affect fertility or increase the chance of birth defects?

Spironolactone can affect men’s ability to maintain an erection, which might affect fertility (ability to get a woman pregnant). There are no data to suggest that a man’s use of spironolactone around the time of conception can increase the chance of birth defects in a woman’s pregnancy. In general, exposures that fathers or sperm donors have are unlikely to increase risks to a pregnancy. For more information, please see the MotherToBaby fact sheet Paternal Exposures at https://mothertobaby.org/fact-sheets/paternal-exposures-pregnancy/.  

Please click here for references.  

This sheet is about exposure to hydroxyzine in pregnancy and while breastfeeding. This information is based on published research studies. It should not take the place of medical care and advice from your healthcare providers.

What is Hydroxyzine?

Hydroxyzine (Vistaril®, Atarax®) is an antihistamine. Antihistamines work by helping the body lower the response to allergens including pollen, nuts, or skin irritants, which can make you itch or develop hives. Some antihistamines, like hydroxyzine, are used to help treat anxiety, nausea, tension, or to help you sleep better.

Sometimes when women find out they are pregnant, they think about changing how they take their medication, or stopping their medication altogether. However, it is important to talk with your healthcare providers before making any changes to how you take your medication. Your healthcare providers can talk with you about the benefits of treating your condition and the risks of untreated illness during pregnancy.

The product label for hydroxyzine recommends women who are pregnant not use this medication. This is because there is not enough information available on the use of hydroxyzine to know what effect, if any, it could have on a human pregnancy. However, the benefit of using hydroxyzine might outweigh possible risks. Your healthcare provider can talk with you about using hydroxyzine and what treatment is best for you.

I take hydroxyzine. Can it make it harder for me to get pregnant?

Studies have not been done to see if taking hydroxyzine can make it harder to get pregnant.

Does taking hydroxyzine increase the chance of miscarriage?

Miscarriage is common and can occur in any pregnancy for many different reasons. In one study of 100 women taking hydroxyzine during pregnancy, an increased chance of miscarriage was not reported.

In animal studies, high doses (more than what would be given to humans) of hydroxyzine were associated with an increased chance of miscarriage.

Does taking hydroxyzine increase the chance of birth defects?

Birth defects can happen in any pregnancy for different reasons. Out of all babies born each year, about 3 out of 100 (3%) will have a birth defect. We look at research studies to try to understand if an exposure, like hydroxyzine, might increase the chance of birth defects in a pregnancy.

In studies involving over 200 women who used hydroxyzine throughout their pregnancy, no increase in birth defects was reported.

Does taking hydroxyzine in pregnancy increase the chance of other pregnancy-related problems?

It is not known if taking hydroxyzine alone can increase the chance of preterm delivery (birth before 37 weeks), or low birth weight (weighing less than 5 pounds, 8 ounces [2500 grams]).

I need to take hydroxyzine throughout my entire pregnancy. Will it cause withdrawal symptoms in my baby after birth?

The use of hydroxyzine during pregnancy has been reported to cause temporary symptoms in newborns soon after birth. These symptoms are sometimes referred to as withdrawal. Two cases of neonatal withdrawal have been reported when the mother used hydroxyzine in the 4 weeks leading up to delivery. One baby had one seizure, and the other experienced jitteriness, jerking movements, and problems with feeding. Not all babies exposed to hydroxyzine will have these symptoms. It is important that your healthcare providers know you are taking hydroxyzine so that if symptoms occur your baby can get the care that is best for them.

Does taking hydroxyzine in pregnancy affect future behavior or learning for the child? 

Studies have not been done to see if hydroxyzine can increase the chance of behavior or learning issues for the child.

Breastfeeding while taking hydroxyzine:

It is not known if hydroxyzine passes into breast milk.  Taking occasional doses of hydroxyzine is not expected to cause side effects in a breastfed infant. Larger doses or taking hydroxyzine for a long period of time might increase the chance for side effects such as drowsiness, irritability, or lower milk supply. There are reports of irritability and drowsiness in infants exposed to hydroxyzine through breast milk. If you suspect the baby has any symptoms, contact the child’s healthcare provider.

The product label for hydroxyzine recommends women who are breastfeeding not use this medication. But the benefit of using hydroxyzine and breastfeeding might outweigh possible risks. Your healthcare providers can talk with you about using hydroxyzine and what treatment is best for you. Be sure to talk to your healthcare provider about all your breastfeeding questions.

If a man takes hydroxyzine, could it affect fertility or increase the chance of birth defects?

Studies have not been done to see if hydroxyzine could affect men’s fertility (ability to get a woman pregnant) or increase the chance of birth defects. In general, exposures that fathers or sperm donors have are unlikely to increase risks to a pregnancy. For more information, please see the MotherToBaby fact sheet Paternal Exposures at https://mothertobaby.org/fact-sheets/paternal-exposures-pregnancy/.

Please click here for references.

This sheet is about having X-rays while pregnant or breastfeeding. This information is based on available published research. It should not take the place of medical care and advice from your healthcare provider.

What are X-rays?

X-rays are a form of energy known as ionizing radiation. X-rays have enough energy to pass through the body. As the X-ray moves through the body, it passes through bones, tissues, and organs differently. This allows an image to be created of the inside of the body. These images are used to help guide medical treatment.

If you have an X-ray, it will be performed with a standard X-ray machine or with a CT (computed tomography) machine. X-ray machines and CT machines only make radiation when they are turned on and actively in use. X-rays will lose energy as they travel through an object. Having X-rays will not make your body radioactive.

This sheet will focus on having diagnostic X-rays taken as a patient. For people who work around X-ray machines, MotherToBaby has a fact sheet at https://mothertobaby.org/fact-sheets/ionizing-radiation-workplace-pregnancy/.

What is radiation?

Radiation is a type of energy. Radiation waves can’t be seen, felt, or smelled. Radiation comes from our natural environment (called background radiation) and can be made by machines.

Radiation is grouped into 2 categories: 1) non-ionizing radiation and 2) ionizing radiation.

• Non-ionizing radiation has lower energy than ionizing radiation. Non-ionizing radiation includes radio waves, microwaves, and lower-energy ultraviolet (UV) sunlight rays. Common sources of non-ionizing radiation include light bulbs, computers, Wi-Fi routers, cell phones, Bluetooth devices, FM radio, GPS, airport body scanning units, and broadcast television.
• Ionizing radiation refers to X-rays, gamma rays, and some of the higher ultraviolet (UV) sunlight spectrum. A small amount of ionizing radiation is used to make X-ray images. Higher doses of ionizing radiation are used to kill cancer cells with cancer radiation therapy. Gamma radiation has also been used in medical treatments.

Could I be exposed to ionizing radiation if I need to go through airport security body scanners?

In the United States, airport body scanning units do not use ionizing radiation. These machines use millimeter wave technology to scan a person’s body. Millimeter-wave technology is non-ionizing radiation in the form of low-level radio waves. Women who are pregnant or breastfeeding a child can use body scanners at airports.

How is the dose of ionizing radiation measured? For example, what is milli-sievert (mSV) or milli-rem (mrem)?

Radiation is measured in several different ways. The international unit of measurement for radiation dose is the milli-sievert (mSv), and in the United States you may also read or hear about “milli-rem”.

1 milli-sievert (mSV) is about the same 100 milli-rem (mrem).

People are surrounded by ionizing radiation every day. Ionizing radiation is in our soil, water, and air. These sources of radiation are called background radiation. Most people are exposed to about 3 mSv (300 mrem) of background radiation every year. During pregnancy, a fetus is exposed to around 1 mSV of background radiation (about 100 mrem).

What is the effective dose of ionizing radiation to me from a diagnostic x-ray?

This depends on what part of the body is being X-rayed. The table below shows the average estimated dose after an x-ray. These doses have not been associated with increased risks to a pregnancy.

X-ray	Effective dose in mSv	Effective dose in mrem
Abdomen	0.6	60
Chest	0.1	10
Dental Bitewing	0.005	0.5
Dental Panoramic	0.026	2.6
DEXA (whole body)	0.001	0.1
Mammogram (4 views)	0.7	70
Pelvis / Hip	0.4	40

 

What is the effective dose of ionizing radiation to my fetus if I had a diagnostic x-ray?

When an X-ray is taken, the actual dose to the embryo/fetus is less than the dose listed in the table above. This is because some of the X-ray is absorbed by the parent’s body before reaching the inside of the uterus (where the fetus is developing). For typical diagnostic X-rays on the parent, a fetus is not expected to be exposed to levels that could cause pregnancy complications.

I had X-rays taken. Can it make it harder for me to get pregnant?

If a woman has had X-rays taken, it is not expected to make it harder for her to get pregnant.

Does having an X-ray increase the chance of miscarriage?

Miscarriage is common and can occur in any pregnancy for many different reasons. Having typical diagnostic X-rays will not increase the chance of miscarriage.

Women with exposure to X-ray doses greater than 50 mSv (5,000 mrem) in the first 2 weeks after conception, which is the time before the egg implants into the uterus, might have a higher chance for miscarriage This dose is much higher than the dose from a typical diagnostic X-ray.

Will having X-rays taken increase the chance of birth defects?

Having a typical diagnostic X-ray will not increase the chance of birth defects. Birth defects can happen in any pregnancy for different reasons. Out of all babies born each year, about 3 out of 100 (3%) will have a birth defect. We look at research studies to try to understand if an exposure might increase the chance of birth defects in a pregnancy. X-ray exposure of less than 50 mSv (5,000 mrem) has not been linked with an increased chance of birth defects.

Does having an X-ray increase the chance of other pregnancy-related problems?

Typical diagnostic X-ray exposure in pregnancy is not expected to increase the chance of other pregnancy-related problems, such as preterm delivery (birth before week 37) or low birth weight (weighing less than 5 pounds, 8 ounces [2500 grams] at birth). Exposure to high doses (around 250 mSv (25,000 mrem)) of ionizing radiation might increase the chance of having a baby with small head size or poor growth. It would be rare for a person to have an exposure that was this high.

Does having an X-ray affect future behavior or learning for the child?

Typical diagnostic X-ray exposure in pregnancy is not expected to increase the chance of learning difficulties or behavior disorders in the child. Exposure to high doses (more than 500 mSv or more than 50,000 mrem) of ionizing radiation during a pregnancy could increase the chance of learning difficulties and intellectual disabilities. In addition, exposure to more than 100 mSV (10,000 mrem) of radiation between the 8^th week and the 15^th week of pregnancy might be associated with learning difficulties and intellectual disability. It would be rare for a person to have an exposure that was this high.

Breastfeeding after having an X-ray:

Exposure to diagnostic X-rays only happens when an X-ray image is being taken and leaves no radiation or radioactivity in the body or milk. Diagnostic X-rays do not affect the breastmilk at the time of a procedure and would not be expected to affect milk production. Be sure to talk to your healthcare provider about all your breastfeeding questions.

If a man has an X-ray, could it affect fertility or increase the chance of birth defects?

Several studies have not found a connection between diagnostic X-ray exposure and lower fertility (ability to get a woman pregnant), birth defects. In general, exposures that fathers or sperm donors have are unlikely to increase risks to a pregnancy. For general information, please see the MotherToBaby fact sheet Paternal Exposures at https://mothertobaby.org/fact-sheets/paternal-exposures-pregnancy/.

Where can I look for more information?

• Health Physics Society: Ask the Experts page: https://hps.org/publicinformation/ate/
• Health Physics Society: Pregnancy and Radiation page: https://hps.org/publicinformation/ate/cat4.html
• Health Physics Society: Radiation Answers page https://www.radiationanswers.org/
• Radiology Info.org for patients: https://www.radiologyinfo.org/en/info/safety-xray

Please click here for references.