Findings by Health Condition

Chronic health conditions—those that go on for a long time and often do not go away completely—are serious. Without treatment, they may be life-threatening. CDC and its partners conduct important research on the effects of medicines used to treat health conditions during pregnancy. Listed below are key findings from some of our studies and suggested reading. This information is not comprehensive and does not include all health conditions or treatment methods.

Are you pregnant or thinking about getting pregnant?

Talk to a healthcare professional about any medicines you are taking or thinking about taking. This includes prescriptions, over-the-counter medicines, herbal and dietary supplements, and vitamins. Although no medicine is completely risk-free, a healthcare professional can help you pick a treatment plan that works for you. Do not start any new medicines or stop a current medicine without talking to a healthcare professional.

Key Findings:

A 2018 study found that that women who took ADHD medicine during early pregnancy may be more likely to have a baby with some types of birth defects compared to women who did not take ADHD medicine.

Key Findings:

In a 2014 study, researchers reviewed more than 50 published scientific articles to see if there was a risk of birth defects from using allergy medicines, like antihistamines, during pregnancy. Researchers found the evidence to be generally reassuring: most antihistamines (e.g., loratadine) do not appear to be linked to birth defects. However, researchers need to study certain antihistamines, especially H₂-receptor antagonists, further to determine if they increase the risk for birth defects.

Key Findings:

A 2014 study and other case reports found that pregnant women taking methotrexate, a medicine used to treat arthritis, have an increased risk of having a baby with birth defects, particularly congenital heart defects.
A 2009 case report suggests that pregnant women taking mycophenolate mofetil (MMF; CellCept), which is used to help prevent transplant organ rejection or to treat lupus nephritis, have an increased risk of having a baby with birth defects.

Key Findings:

A 2009 study found that bronchodilators, a particular type of asthma medicine, might increase the risk for congenital heart defects.
A 2007 study found that corticosteroids, a type of medicine used to treat asthma, might increase the risk of having a baby born with cleft lip and/or cleft palate.

Frequency of Use:

In a 2011 study of pregnancies between 1998 and 2005, about 1 in 20 women reported using an antidepressant (frequently used to treat depression or anxiety) 3 months before becoming pregnant or during the pregnancy.
- Use of selective serotonin-reuptake inhibitors (SSRIs) was reported most often (about 1 in 25 women), followed by bupropion [Wellbutrin®] (about 1 in 100 women).
- About 1 in 3 women using an antidepressant medicine in the first month of pregnancy stopped its use by the second month of pregnancy, which appears to be related to the time women often find out they are pregnant.
- Data from 4 states showed that the frequency of reported antidepressant use during pregnancy increased from 1 in 40 women in 1998 to about 1 in 12 women in 2005.
A 2012 study of pregnant and non-pregnant women 18-44 years old (from 2005-2009) showed that half of pregnant and non-pregnant women with depression received treatment, with prescription medicine as the most common type of treatment.

Key Findings:

A 2020 study clarified previous research findings on the relationship between use of antidepressants during early pregnancy and risk for specific birth defects, finding that the risk for birth defects varied depending on the specific antidepressant medicines used.
Abruptly stopping the use of antidepressants can have serious consequences, and some women need to take antidepressants to appropriately manage their health condition.
At the same time, several studies have shown an increased risk for congenital heart defects when selective serotonin-reuptake inhibitors (SSRIs) are taken during early pregnancy.
Findings in a 2015 study refute some earlier reported links but confirm other links observed between birth defects and some SSRIs.
A 2007 study using data from the National Birth Defects Prevention Study showed that taking SSRIs during pregnancy may increase the risk of anencephaly, craniosynostosis, or omphalocele.
A 2010 study found that taking bupropion [Wellbutrin®](used to treat depression/anxiety and to quit smoking) during pregnancy might increase the risk of having a baby with certain congenital heart defects.
A 2013 study looked at venlafaxine use during the first trimester (first 3 months) of pregnancy and the risk for birth defects. Researchers found that venlafaxine use during early pregnancy was not common, but that it was more common among mothers of babies born with certain birth defects , including anencephaly, some congenital heart defects, cleft palate, and gastroschisis. This is the first study to show these links, so more research is needed to understand and confirm them.

Key Findings:

In a 2011 study researchers found that use of valproic acid and carbamazepine, medicines used to treat epilepsy and sometimes other diseases, such as migraine headaches and bipolar disorder, during pregnancy was linked to an increased risk of cleft palate and spina bifida.

Key Findings:

A 2009 study found that pregnant women who have high blood pressure (hypertension) or took certain hypertension medicines appeared to have an increased risk of having a baby with certain congenital heart defects.

Frequency of Use:

In a 2009 study of U.S. pregnancies between 1997 and 2003, almost a third of women reported using antibiotics 3 months before becoming pregnant or while pregnant.

2 in 100 women reported antibiotic use 3 months before becoming pregnant.
Antibiotic use increased during pregnancy, peaking at about 6 in 100 women during the fourth month.
Penicillins were the most frequently reported antibiotics, used by 6 in 100 pregnant women.

Key Findings:

A 2021 study using data from the National Birth Defects Prevention Study showed that use of cough medications to treat symptoms of cold and flu shortly before and during early pregnancy may be linked to birth defects such as neural tube defects, limb defects, omphalocele, and gastroschisis. Some of these relationships were observed for the first time and need confirmation in other future studies.
In a 2009 study, taking penicillins, erythromycins, or cephalosporins (antibiotics used to treat infections), did not appear to increase the risk of birth defects. However, use of sulfonamide (often used in combination with trimethroprin, which is thought to increase the risk for birth defects) or nitrofurantoin was linked to several birth defects.

Key Findings:

A 2010 study found that taking clomiphene citrate (commonly used to help women who have difficulty getting pregnant) just before or during early pregnancy might increase the risk of having a baby with certain birth defects. However, it is difficult to determine whether these findings are due to the use of the clomiphene citrate or because of some underlying health condition causing both the women’s infertility and the birth defect.
A 2005 study found that taking progestins (used to treat infertility and an ingredient found in birth control pills) during early pregnancy might increase the risk of having a baby with hypospadias.

Key Findings:

A 2018 study found that taking ondansetron (Zofran®), a medicine used to treat nausea and vomiting, during early pregnancy did not appear to increase the chance of having a baby with a birth defect.

Frequency of Use:

A 2021 study found that in 2017, about 1 in 5 women aged 15-44 years with private insurance and about 1 in 4 women enrolled in Medicaid filled at least one opioid prescription.

Key Findings:

A 2017 review article found that use of opioids during pregnancy may be linked to various birth defects such as oral clefts, congenital heart defects, and clubfoot. However, many of the studies reviewed had issues with study methods and quality.
A 2013 study found that mothers who used opioids in the first two months of pregnancy were twice as likely to have a pregnancy affected by a severe birth defect of the brain and spine (anencephaly, encephalocele, or spina bifida) than mothers who didn’t use opioids during pregnancy.
A 2011 study found that some birth defects, including spina bifida and certain congenital heart defects, were linked with the use of opioids during early pregnancy.
A 2010 study found that taking acetaminophen (over-the-counter medicine used for pain relief) during the first trimester (first 3 months) of pregnancy does not appear to increase the risk of major birth defects. Also, taking acetaminophen might decrease the risk of some birth defects in the baby when a pregnant woman uses it to treat a fever. This is because untreated fever can increase the risk of some birth defects.

Key Findings:

A 2005 study found that taking progestins (an ingredient found in birth control pills) during early pregnancy might increase the risk of having a baby with hypospadias.

Key Findings:

A 2009 study supported previous links between the use of thyroid medicines during pregnancy and hydrocephalus or hypospadias.
A 2007 study suggested that pregnant women who have a thyroid disorder might have an increased risk of having a baby with craniosynostosis.

Frequency of Use:

In a 2010 study of pregnancies between 1998 and 2004, 1 in 10 women reported using an herbal product (not including prenatal vitamins) 3 months before becoming pregnant or during pregnancy.

During pregnancy, slightly less than 1 in 10 women used an herbal product and use was highest in the first trimester (first 3 months of pregnancy).
Women were more likely to use an herbal product if they were older than 30 years or had more than a high school education.
Ginger and ephedra were the most commonly reported herbal products used early in pregnancy; use of teas and chamomile were commonly reported throughout pregnancy.

Key Findings:

Findings from a 2013 study were reassuring that hypospadias is not related to use of the most common medicines and herbal supplements taken during early pregnancy.
A 2008 study suggested a link between use of weight loss products before conception or during early pregnancy and certain birth defects, but the possible mechanism for how this might occur is not clear.

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