This sheet is about exposure to methadone 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 methadone? 

Methadone is an opioid medication. Opioids are sometimes called narcotics. Methadone has been used to treat opioid use disorder (to help people stop using heroin or opioid medications) and pain.  

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. 

If you have been taking methadone regularly, have a dependency, or opioid use disorder, talk with your healthcare provider before you stop taking your medication. Stopping an opioid medication suddenly could cause you to go into withdrawal. It is not known if or how withdrawal might affect a pregnancy. It is suggested that any reduction in methadone be done slowly, and under the direction of your healthcare provider. 

Can I take methadone to treat opioid use disorder during pregnancy?  

Methadone has been used to treat opioid use disorders in pregnancy since the early 1970s. Studies have found that following the treatment plan for opioid use disorder can help increase the chances of a healthy pregnancy. People who stop taking the medication used to treat opioid use disorder have an increased chance of relapse (misusing opioids again). Misusing opioids (using in greater amounts than recommended by a healthcare provider or using an opioid without a prescription) increases the chance of pregnancy complications.  

Because of how the body changes during pregnancy, your healthcare provider might talk with you about changing your methadone dose during the pregnancy. 

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

Taking methadone may make it harder to get pregnant.   

Does taking methadone increase the chance of miscarriage?  

Miscarriage is common and can occur in any pregnancy for many different reasons. It is not known if methadone can increase the chance of miscarriage. 

Does taking methadone 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 methadone, might increase the chance of birth defects in a pregnancy. 

It is not known whether methadone can increase the chance of birth defects. Some studies have not found a higher risk, while others suggested a possible increase when methadone is used in the first trimester. Two studies found a slightly higher chance of a small, recessed jaw (Pierre Robin sequence). However, other exposures were also present, making it hard to know what caused this outcome 

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

Some studies have found higher chances of preterm delivery (birth before week 37) and low birth weight (weighing less than 5 pounds, 8 ounces [2500 grams] at birth) when methadone is used during pregnancy. This higher chance is found when methadone use is compared to someone who did not take opioids at all. These outcomes might be more likely if someone takes more methadone than their healthcare provider recommends, or if someone is using methadone without a prescription. 

Taking opioids in higher amounts or for longer than recommended by a healthcare provider can increase the chance of poor growth of the fetus, stillbirth, preterm delivery, and C-section.  

Will my baby have withdrawal (neonatal opioid withdrawal syndrome) if I continue to take methadone? 

Neonatal opioid withdrawal syndrome (NOWS) is the term used to describe withdrawal symptoms in newborns after exposure to opioids during pregnancy. NOWS symptoms can include irritability, crying, sneezing, stuffy nose, poor sleep, extreme drowsiness (very tired), yawning, poor feeding, sweating, tremors, seizures, vomiting, and diarrhea. Most often, symptoms of NOWS appear 2 days after birth and may last more than 2 weeks. The chance that NOWS will occur depends on the length of time and/or the dose of opioid taken during pregnancy, if other medications were also taken, if baby was born preterm, and/or size of the baby at birth. For methadone, NOWS is more likely if high amounts of methadone are taken late in pregnancy. If opioids were taken in pregnancy, it is important to let your baby’s healthcare providers know so that they can check for symptoms of NOWS and provide the best care for your newborn. 

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

Some studies, including one that followed children up to 3 years old, did not find differences in development in children who were exposed to methadone during pregnancy compared to those who were not. Other studies on methadone and opioids as a general group have found problems with learning and behavior in children exposed during pregnancy. This includes one that followed children up to 4 years old. However, many of these children also had other exposures during pregnancy. It is hard to tell if the reported outcomes are due to medication(s), environment, or other factors.   

Breastfeeding while taking methadone: 

Talk with your healthcare provider about why you are taking methadone and medications that can be used while you are breastfeeding. Methadone can pass into breastmilk. The amount of methadone that gets into breast milk varies, based on the dose and someone’s personal ability to metabolize (break down) the medication. Taking up to 100 mg of methadone per day is not expected to cause problems for most healthy, full-term breastfed babies who were already exposed to methadone during pregnancy. Some studies have found that babies who were exposed to methadone during pregnancy and are breastfed have shorter hospital stays, less need for NOWS treatment, and shorter treatment than those who are not breastfed. Talk with your healthcare provider or a MotherToBaby specialist about your medication. The chance of side effects can depend on factors like your baby’s age, your dose, and other individual circumstances. 

The use of some opioids in breastfeeding might cause babies to be very sleepy and have trouble latching on. Some opioids can cause trouble with breathing. If you are using any opioid, talk to your healthcare provider about how to use the least amount for the shortest time and how to monitor (watch) your baby for any signs of concern. Contact the baby’s healthcare provider immediately if your baby has any problems such as increased sleepiness (more than usual), trouble feeding, trouble breathing, or limpness. Be sure to talk to your healthcare provider about all your breastfeeding questions.  

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

Taking opioids, including methadone, for a long time may affect men’s fertility. It is not known if a man’s use of methadone could 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 lithium 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 lithium?

Lithium is a medication that has been used to treat bipolar disorder and other mental health conditions. Lithium is sold under many brand names, including Cibalith-S®, Eskalith®, Lithane®, Lithobid® and Lithonate®. 

Sometimes when people 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.  

Stopping lithium might cause a return of symptoms (relapse), especially if it is stopped quickly. If you keep taking lithium, your healthcare provider can check your blood levels of lithium throughout pregnancy. You might need to increase your dose during pregnancy to prevent relapse. Talk with your healthcare provider about monitoring and adjusting your lithium dose as needed. 

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

The time it takes to metabolize (to process) medication is not the same for everyone. In healthy non-pregnant adults, it takes up to 9 days, on average, for most of the lithium to be gone from the body. Studies have also shown that the longer a person has been on lithium, the longer it might take for their body to clear it completely after stopping the medication. 

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

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

Does taking lithium increase the chance of miscarriage?

Miscarriage is common and can occur in any pregnancy for many different reasons. It is not known if lithium can increase the chance of miscarriage. Two studies reported an increase in miscarriage with use of lithium in pregnancy. However, neither study could control for other important factors, such as other medical conditions or other exposures. A third study did not find an increased chance of miscarriage with lithium use. As there can be many causes of miscarriage, it is hard to know if a medication, the medical condition being treated, or other factors are the cause of a miscarriage.  

Does taking lithium 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 lithium, might increase the chance of birth defects in a pregnancy.  

Some studies suggest a small increase in the chance of heart defects with the use of lithium in the first trimester, especially a rare heart defect called Ebstein’s anomaly (when one of the valves that controls blood flow in the heart forms in a different place than expected). Other studies have not shown an increased chance of Ebstein’s anomaly or other heart defects with the use of lithium. 

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

Some studies suggest that using lithium during pregnancy is associated with an increased chance of preterm delivery (birth before week 37). Some studies have reported higher birth weight and low blood sugar in infants following exposure to lithium during pregnancy, while other studies have not reported differences in birth weight. Lithium has not been associated with low birth weight (weighing less than 5 pounds, 8 ounces [2500 grams] at birth). There are case reports of polyhydramnios (too much amniotic fluid around the fetus, which can lead to preterm delivery and other pregnancy complications) with the use of lithium in pregnancy.  

Using lithium during pregnancy might cause goiter (when the thyroid gland grows larger than usual) and hypothyroidism (very low activity of the thyroid gland) in people who are pregnant. There are also case reports of these symptoms in babies exposed to lithium during pregnancy. If you are pregnant and taking lithium, talk with your healthcare provider about having your thyroid function monitored throughout pregnancy so you can be treated, if needed.  

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

The use of lithium during pregnancy can cause temporary symptoms in newborns soon after birth. These symptoms are sometimes referred to as withdrawal. There have been reports of low muscle tone (floppiness), sedation (sleepiness), trouble with breathing and feeding, and jaundice (yellowing of the skin and eyes). These symptoms were reported when lithium was used near the time of delivery, especially if the mother’s own blood lithium level was high. Not all babies exposed to lithium will have symptoms. It is important that your healthcare providers know you are taking lithium so that if symptoms occur your baby can get the care that is best for them.  

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

Small studies on children 3 to 15 years old who were exposed to lithium during pregnancy did not find significant differences in physical, mental, or behavioral problems when compared to children who were not exposed to lithium during pregnancy. 

What screenings or tests are available to see if my pregnancy has birth defects or other issues?

Prenatal ultrasounds can be used to screen for some birth defects, such as Ebstein’s anomaly. Ultrasound can also be used to monitor the growth of the pregnancy. Talk with your healthcare provider about any prenatal screenings or testing that are available to you. There are no tests available during pregnancy that can tell how much effect there could be on future behavior or learning. 

Breastfeeding while taking lithium: 

Lithium passes into the breast milk. The amount of lithium that gets into a baby’s blood through breast milk is much less than the amount in the woman’s blood. If you take lithium while breastfeeding, monitor the baby for symptoms such as restlessness, low muscle tone, or trouble feeding. There are a few reports of reversible changes in a baby’s thyroid and kidney function, so it has been recommended to monitor the baby’s lithium level, thyroid function, and kidney function, especially in very young or preterm infants. If you suspect the baby has any symptoms, contact the child’s healthcare provider.  

The product label for lithium recommends not using this medication while breastfeeding. However, the benefit of using lithium and breastfeeding might outweigh possible risks. Continuing to take lithium after delivery lowers the chance of a relapse of bipolar disorder. Postpartum relapses are very serious and can lead to postpartum psychosis, a severe mental health condition. Your healthcare providers can talk with you about using lithium and what treatment is best for you. Be sure to talk to your healthcare provider about all your breastfeeding questions. 

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

There are reports of lower sperm quality and less sperm movement with lithium use in men. One of these reports found no effects on men’s fertility (ability to get a partner pregnant). Lower sex drive was reported in another study, but this is a common side effect of depression and might not be due to lithium. In general, exposures that men 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 carbamazepine 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 carbamazepine?

Carbamazepine is a medication that has been used to control seizures. It has also been used to treat bipolar disorder, schizophrenia, and pain disorders. A brand name for carbamazepine is Tegretol®.

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. If you have been taking carbamazepine and you suddenly stop taking it, you could experience a return of your symptoms (relapse). Your healthcare providers can talk with you about the benefits of treating your condition and the risks of untreated illness during pregnancy.

Carbamazepine might make hormonal contraception (birth control) not work as well. If you are taking carbamazepine and do not want to become pregnant, talk to your healthcare provider about effective ways to prevent pregnancy.

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

It is not known if carbamazepine can make it harder to get pregnant. Women who use seizure medications for a long time might not have regular periods, which might make it harder to get pregnant.

Does taking carbamazepine increase the chance of miscarriage?

Miscarriage is common and can occur in any pregnancy for many different reasons. A few studies have reported slightly more miscarriages among women taking carbamazepine during pregnancy, while other studies have not reported this finding. As there can be many causes of miscarriage, it is hard to know if a medication, the medical condition being treated, or other factors are the cause of a miscarriage.

Does taking carbamazepine 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 carbamazepine, might increase the chance of birth defects in a pregnancy.

Taking carbamazepine in early pregnancy can increase the chance of neural tube defects. A neural tube defect happens when the spinal cord or the skull do not form properly. The most common type of neural tube defect is spina bifida (an opening anywhere along the spine). In the general population, the chance of a neural tube defect happening in a pregnancy is less than 1 in 1000 (less than 1% chance). For someone taking carbamazepine, the chance of a neural tube defect might increase to about 1 in 100 (1% chance). In the general population, taking folic acid before and during early pregnancy has been shown to lower the chance of neural tube defects. If you take carbamazepine, your healthcare provider might recommend that you take extra folic acid before and during pregnancy.

Other studies on carbamazepine have reported a higher chance of other major birth defects, such as heart or kidney defects, hypospadias (opening of the penis is on the underside instead of at the tip), and cleft lip and/or palate (opening in the upper lip or the roof of the mouth). Some studies have also suggested an increased chance of minor birth defects, such as a small nose, greater distance between the nose and upper lip, small fingernails and toenails, and smaller head size. The chance of birth defects might be higher with higher doses of carbamazepine. Since some of the conditions that carbamazepine is used to treat (like epilepsy) can also increase the chance of birth defects, it is hard to know if the medication, the condition being treated, or other factors are the cause of a birth defect.

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

It is not known if carbamazepine 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 studies have suggested an increased chance of poor growth of the fetus. Some of the conditions that carbamazepine is used to treat can also increase the chance of pregnancy-related problems.

Taking carbamazepine during pregnancy can lower vitamin K levels in the fetus and cause bleeding problems in some newborns. People who are pregnant and taking carbamazepine should talk with their healthcare providers about taking vitamin K supplements near the end of pregnancy. You can also talk with your child’s healthcare provider before delivery about giving your baby a vitamin K supplement at birth.

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

It is not known if carbamazepine can increase the chance of behavior or learning issues for the child. Some studies have found a small increased chance for speech delay or lower IQ scores in children who also have minor facial defects after exposure to carbamazepine during pregnancy. Other studies have found no differences in child development or intelligence.

What screenings or tests are available to see if my pregnancy has birth defects or other issues?

Blood screenings during pregnancy can look for neural tube defects and other issues. Prenatal ultrasounds can be used to screen for some birth defects, such as neural tube defects, heart defects, and cleft lip or palate. Ultrasound can also be used to track the growth of the pregnancy. Talk with your healthcare provider about any prenatal screenings or testing that are available to you. There are no tests available during pregnancy that can tell how much effect there could be on future behavior or learning.

Breastfeeding while taking carbamazepine:

Carbamazepine gets into breast milk in small amounts. Most breastfeeding children have not had reported side effects. Breastfeeding while taking just carbamazepine (no other medications) has not been shown to affect child growth or development. If you suspect the baby has any symptoms of jaundice (yellowing skin and eyes), drowsiness, or poor weight gain, contact the child’s healthcare provider. If needed, healthcare providers can measure the levels of carbamazepine in a child’s blood. Be sure to talk to your healthcare provider about all your breastfeeding questions.

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

It is not known if carbamazepine could affect men’s fertility (ability to get a woman pregnant) or increase the chance of birth defects. Small studies have suggested that carbamazepine might affect sperm production, which might make it harder to conceive a 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 alcohol 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 alcohol? 

Alcohol is the ingredient in beer, malt liquor, wine, and spirits (“hard liquor”) that can cause feelings of being “buzzed” or drunk. Alcohol can be found in some canned and bottled beverages such as hard lemonade, hard iced tea and others. Alcohol is also an ingredient in some over the counter and prescription medications such as cough syrup, liquid vitamins and others. Alcohol can be listed in products as ethanol, ethyl alcohol or alcohol. 

One standard serving of beer (12 ounces), malt liquor (8 ounces), wine (5 ounces), and spirits (1.5 ounces) all contain similar amounts of alcohol. Medications and liquid vitamins might contain from 5% alcohol to 12% or more. 

The measurement of the amount of alcohol in the blood is called blood alcohol concentration (BAC). Binge drinking has been defined as a pattern of drinking alcohol that results in a BAC of 0.08% or more. This typically happens if a female has 4 or more drinks in about 2 hours. (For males, it is typically 5 or more drinks within about 2 hours). Heavy alcohol use in females has been defined as consuming 4 or more drinks on any day or 8 or more drinks per week. (For males, it has been defined as consuming 5 or more drinks on any day or 15 or more per week.) While this can vary, it is recommended to avoid all alcohol use in pregnancy. 

Help is available: Talk with your healthcare provider as soon as possible about your drinking. They can go over what resources are available to help you stop. If you do not have a healthcare provider or cannot get a hold of them and need help quitting, there is free help available. Call 800-662-HELP (4357) or visit https://alcoholtreatment.niaaa.nih.gov/. 

Can I drink beers labeled “no-alcohol” or “low-alcohol” during pregnancy?  

Beers labeled “no-alcohol” or “low-alcohol” might contain higher levels of alcohol than listed the label. For this reason, these beverages should be avoided in pregnancy. 

I drink alcohol. Can it make it harder for me to get pregnant?  

It is not known if drinking alcohol can make it harder to get pregnant. Some research raises concerns about heavy drinking and fertility (ability to get pregnant).  

Does drinking alcohol increase the chance of miscarriage?  

Miscarriage is common and can occur in any pregnancy for many different reasons. Studies on the chance of miscarriage with alcohol exposure during pregnancy have had mixed results. Some studies have found an increased chance of miscarriage and others have not. As there can be many causes of miscarriage, it is hard to know if alcohol, a medical condition being treated (such as depression), or other factors (such as age, health, other exposures, such as cigarettes) are the cause of a miscarriage.  

Does drinking alcohol 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 alcohol, might increase the chance of birth defects in a pregnancy.  

Drinking alcohol in pregnancy can cause Fetal Alcohol Spectrum Disorder (FASD). FASD includes a range of effects related to alcohol exposure in pregnancy, from physical birth defects (including defects of the heart, kidneys, and bones) to changes in brain development. These effects can range from mild to severe. Depending on the specific effects or combination of effects, healthcare providers use different terms to describe different kinds of FASD. 

The most severe form of FASD is Fetal Alcohol Syndrome (FAS). Children with FAS have a pattern of birth defects that include specific facial features, a smaller head and body size, and effects on brain development that can cause significant challenges in learning and behavior. 

The chance of FASD depends on how much alcohol is consumed during pregnancy, how often drinking occurs, and other factors such as genetics and nutrition. The risk can vary even for the same person across different pregnancies. Research has shown that daily drinking and binge drinking are associated with a higher risk of FASD, while the effects of smaller amounts of alcohol exposure are less certain. 

I just found out I am pregnant and last weekend I had a beer. Will my baby have FASD? 

Having a single serving of alcohol one time is much less concerning than heavy or binge drinking and is considered less likely to cause alcohol-related problems for the baby. However, it is recommended that you avoid further use of alcohol during your pregnancy. 

Does drinking alcohol in pregnancy increase the chance of other pregnancy-related problems? 

Drinking alcohol might increase the chance of preterm delivery (birth before week 37) and for the fetus to be smaller than expected. Studies have reported higher rates of stillbirth among people who drink alcohol during pregnancy. 

If I drink alcohol in pregnancy, will it cause withdrawal symptoms in my baby after birth? 

The use of alcohol late during pregnancy can cause temporary symptoms in newborns soon after birth. These symptoms are sometimes referred to as withdrawal. Symptoms of withdrawal can include involuntary shaking movements (tremors), increased muscle tone, restlessness, and excessive crying. It is important that your healthcare providers know about your alcohol use so that if symptoms occur your baby can get the care that is best for them. 

Does drinking alcohol during pregnancy affect future behavior or learning for the child?  

Prenatal alcohol exposure is a leading cause of problems with brain development in the United States. The effects of alcohol on brain development include problems with learning and memory, speech and language, aggression, attention, controlling emotions (tantrums, mood issues, impulsivity, communication, depression/anxiety), and problems with daily life skills such as bathing and playing with others.  

Talk to your baby’s healthcare provider about any alcohol use during pregnancy. They can check your baby after birth for possible effects and continue to watch for learning or behavior concerns as your child grows. While FASD cannot be cured, early diagnosis and support can help children do better. Your child’s healthcare provider can also help connect you with services and resources for families affected by alcohol exposure during pregnancy. 

What screenings or tests are available to see if my pregnancy has birth defects or other issues? 

There are no tests available to diagnose FASD during pregnancy. Prenatal ultrasounds can be used to screen for some birth defects, such as heart or kidney defects. Ultrasound can also be used to watch the growth of the pregnancy. Talk with your healthcare provider about any prenatal screenings or testing that are available to you. There are no tests available during pregnancy that can tell how much effect there could be on future behavior or learning. 

Breastfeeding while drinking alcohol: 

Alcohol gets into breast milk. The amount of alcohol in breast milk is about the same as in the blood. Alcohol passes back and forth between the bloodstream and the breast milk. Only time can lower the amount of alcohol in breast milk. Pumping and discarding milk, drinking water, taking caffeine, or exercising do not help the body get rid of alcohol faster. It takes about 2 to 2.5 hours for each standard drink to clear from breast milk. Wait another 2-2.5 hours per drink for each additional drink. If needed, pumping during this time can help you stay comfortable and keep up your milk supply. Discarding this pumped milk will help to avoid exposing the baby to any alcohol in the milk. Drinking alcohol can also make it harder for the body to make milk.  

The infant brain continues to grow after birth. Effects on child development from alcohol in breast milk are not well studied. One study suggested problems with motor development following exposure to alcohol in breast milk, but other studies did not show the same results. Some reports found that babies exposed to alcohol through breast milk might eat less and/or have changes in their sleeping patterns. If you suspect the baby has any symptoms, contact the child’s healthcare provider.  

Having more than one drink per day is not recommended while breastfeeding. However, since breastfeeding has known benefits for the baby, talk with your baby’s healthcare provider about how much and how often you drink so they can help you weigh the risks and benefits of continuing to breastfeed. Be sure to talk to your healthcare provider about all your breastfeeding questions.  

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

Some studies have shown that drinking alcohol lowers men’s fertility (ability to get a partner pregnant). Men’s exposure to alcohol is not known to 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 Zika virus in pregnancy or 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 Zika? How do people get it?  

Zika is a virus that is usually spread by infected mosquitoes. Not all mosquitoes carry the Zika virus, and not every person bitten by an infected mosquito will get Zika. Other ways people can get Zika include sexual contact with an infected partner (vaginal, anal, or oral sex, or sharing of sex toys), and through contact with infected blood (from transfusions, needle sticks, or sharing needles with an infected person). During pregnancy, Zika can pass from the pregnant woman to the fetus. When this happens, there is an increased chance of serious birth defects and developmental problems. 

Four out of 5 people (80%) who have Zika virus do not have symptoms. Those who do have symptoms usually have a mild flu-like illness with fever, rash, headache, joint and/or muscle pain, and conjunctivitis (“pink eye”). Symptoms can begin 3-7 days after being infected and can last for several days to a week. There is no cure or vaccine for Zika. The symptoms of Zika can be treated, but treatment does not prevent the virus from spreading. Even if an infected person has no symptoms, they can still pass the virus to others through sex or to a fetus during pregnancy.   

Can I be tested for Zika? 

People who have Zika symptoms and have traveled to an area with current or past Zika virus transmission or had sex with someone who recently traveled to one of these areas, should be tested. Testing is not routinely recommended if you are pregnant and do not have Zika symptoms but can be considered after talking to your healthcare provider. The Centers for Disease Control and Prevention (CDC) has more information about testing here: https://www.cdc.gov/zika/testing/index.html.  

How can I protect myself from Zika virus during travel? 

Prevent mosquito bites during and after travel by using insect repellent and taking other steps recommended by the CDC at https://www.cdc.gov/mosquitoes/prevention/preventing-mosquito-bites-while-traveling.html. MotherToBaby has fact sheets for Insect Repellents at https://mothertobaby.org/fact-sheets/insect-repellents/ and DEET at https://mothertobaby.org/fact-sheets/deet-nn-ethyl-m-toluamide-pregnancy/. 

Depending on where you travel, it might be recommended to take steps to prevent sexual transmission of Zika (getting or passing the virus through sex) and/or delaying pregnancy after travel. To prevent sexual transmission of Zika, use condoms or dental dams, do not share sex toys, and do not have sex during travel and for a period after travel (2 months for females or 3 months for males). Follow these same timeframes (2 months for females and 3 months for males) if you want to wait to get pregnant until a potential Zika virus infection has cleared from the body. See below for specific recommendations based on Zika risk at your destination(s). 

Check for Zika risk at your destination(s). Before traveling, look at the CDC website for any active Zika Travel Health Notices at: https://wwwnc.cdc.gov/travel/notices. 

• If you are pregnant, avoid traveling to areas with active Zika Travel Health Notices. If you must travel, prevent mosquito bites and sexual transmission of Zika virus during and after travel according to the CDC guidelines. 

• If your female partner is pregnant and you choose to travel to an area with an active Zika Travel Health Notice, prevent mosquito bites and sexual transmission during and after travel according to the CDC guidelines.  

• If you are planning a pregnancy and you travel to an area with an active Zika Travel Health Notice, prevent mosquito bites, prevent sexual transmission, and delay pregnancy according to the CDC guidelines. 

Some areas still have low levels of Zika virus transmission even if there is no active Zika Travel Health Notice. For information about Zika risk in specific countries and territories, see https://www.cdc.gov/zika/geo/index.html. It is hard to know the exact level of transmission in many areas. Carefully consider the risks of Zika before traveling to areas with current or past transmission of Zika virus.  

• If you or your female partner are pregnant and you travel to an area with current or past transmission, prevent mosquito bites during and after travel. If you are concerned about the risks of Zika, prevent sexual transmission during and after travel according to the CDC guidelines.  

• If you or your female partner are planning a pregnancy and you travel to an area with current or past transmission, prevent mosquito bites during and after travel. If you are concerned about the risks of Zika, prevent sexual transmission during and after travel, and consider delaying pregnancy according to the CDC guidelines. 

Does having Zika virus increase the chance of miscarriage? 

Miscarriage is common and can occur in any pregnancy for many different reasons. Zika infection in pregnancy can increase the chance of miscarriage. 

Does having Zika virus in pregnancy 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 Zika, might increase the chance of birth defects in a pregnancy.  

When a pregnant woman is infected with Zika, the virus can sometimes pass to the fetus. If this happens, there is an increased chance for a range of serious birth defects and developmental problems in the baby. The most severe outcome of Zika exposure in pregnancy is congenital Zika syndrome (CZS). Babies with CZS can have severe microcephaly (very small head size), serious brain changes (including a thinner outer layer of the brain, and calcium deposits in the brain where damage has occurred), eye defects (including scarring and vision problems), contractures (tightening that reduces movement) of the joints, and very stiff muscles. Other possible outcomes include feeding difficulties (such as trouble swallowing), hydrocephalus (a buildup of fluid in the brain), seizures, and hearing loss.  

Some babies may only have some CZS features. Other babies may be born with no apparent effects from Zika infection but can later have slower head and brain growth (postnatal microcephaly). Research has also shown that even when a baby does not have noticeable Zika-associated issues at birth, there is still a chance they can have issues later on, such as seizures or delays in meeting developmental milestones (for more details see the question: “Does having Zika virus in pregnancy affect future behavior or learning for the child?” below). 

The chance for a baby to experience CZS or other complications from Zika virus seems to be highest when the infection happens late in the first trimester or in the second trimester. However, Zika infection at any point in pregnancy can lead to serious problems in the baby. There is no safe time to get infected with Zika virus during pregnancy.  

Does having Zika virus increase the chance of other pregnancy related problems? 

Zika infection in pregnancy can increase the chance of preterm delivery (birth before week 37), low birth weight (weighing less than 5 pounds, 8 ounces [2500 grams] at birth), small for gestational age (the fetus being smaller than expected for the timing in pregnancy), and stillbirth. Children with CZS have an increased chance of death due to complications from the syndrome.  

Does having Zika virus in pregnancy affect future behavior or learning for the child? 

Children with CZS have an increased chance of learning issues due to the serious effects the virus can have on the brain. Language delays, motor delays (crawling or walking on time), and trouble reaching other developmental milestones can occur. Babies infected with Zika during pregnancy may have more trouble with thinking, learning, and remembering.  

What screenings or tests are available to see if my pregnancy has birth defects or other issues? 

Prenatal ultrasounds can be used to screen for some birth defects, such as microcephaly. Ultrasound can also be used to monitor the growth of the pregnancy. Talk with your healthcare provider about any prenatal screenings or testing that are available to you. There are no tests available during pregnancy that can tell how much effect there could be on future behavior or learning.  

Breastfeeding while I have Zika virus: 

Zika virus has been found in breast milk. Although a few cases of Zika have been reported in breastfed infants of women who were infected with Zika virus, it is not clear if the infants got the virus from the breast milk. In most cases, the virus is not expected to pass to the baby from the milk. Experts believe that the benefits of breastfeeding outweigh any potential risks of Zika virus infection through breastfeeding.  

Children with CZS can have trouble with feeding, such as issues with swallowing or suckling. If you are concerned about your baby’s feeding habits or weight gain, talk with your baby’s pediatrician. Be sure to talk to your healthcare provider about all your breastfeeding questions. 

If a man has Zika virus, can it affect his fertility or increase the chance of birth defects? 

One study showed that having a Zika infection lowered sperm count (number of sperm produced), which could temporarily affect men’s fertility (ability to get a woman pregnant). Sperm count returned to normal within several months after the infection cleared. 

If a man has Zika, he can pass the virus to his partner through unprotected sex. This can increase the chance of birth defects in a woman’s pregnancy. Men who might have been exposed to Zika virus should take steps to avoid passing the virus to a partner through sex, even if they do not have symptoms (for more information, see https://www.cdc.gov/zika/prevention/index.html). For more general information on paternal exposures, please see the MotherToBaby fact sheet at https://mothertobaby.org/fact-sheets/paternal-exposures-pregnancy/. 

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