Safety of Medications During Pregnancy

Immunization Overview of Immunization Immunization (vaccination) helps the body defend itself against diseases caused by certain bacteria or viruses. Immunity (the ability of the body to defend itself against diseases caused by... read more is as effective in women who are pregnant as in those who are not. (See also Centers for Disease Control and Prevention (CDC): Pregnancy and Vaccination.)

Vaccines Overview of Immunization Immunization (vaccination) helps the body defend itself against diseases caused by certain bacteria or viruses. Immunity (the ability of the body to defend itself against diseases caused by... read more made with a live virus (such as the rubella vaccine Measles, Mumps, and Rubella Vaccine The measles, mumps, and rubella (MMR) vaccine is a combination vaccine that helps protect against these three serious viral infections. The vaccine contains live but weakened measles, mumps... read more and varicella vaccine Varicella Vaccine The varicella vaccine helps protect against chickenpox (varicella), a very contagious infection caused by the varicella-zoster virus. It causes an itchy rash that looks like small blisters with... read more ) are not given to women who are or might be pregnant.

Other vaccines (such as those for cholera Vaccines Cholera is a serious infection of the intestine that is caused by the gram-negative bacteria Vibrio cholerae and that causes severe diarrhea, which can be fatal without treatment. People... read more , hepatitis A Hepatitis A Vaccine The hepatitis A vaccine helps protect against hepatitis A. Typically, hepatitis A is less serious than hepatitis B. Hepatitis A often causes no symptoms, although it can cause fever, nausea... read more , hepatitis B Hepatitis A Vaccine The hepatitis A vaccine helps protect against hepatitis A. Typically, hepatitis A is less serious than hepatitis B. Hepatitis A often causes no symptoms, although it can cause fever, nausea... read more , plague, rabies Prevention Rabies is a viral infection of the brain that is transmitted by animals and that causes inflammation of the brain and spinal cord. Once the virus reaches the spinal cord and brain, rabies is... read more , and typhoid Vaccination Typhoid fever is caused by certain types of the gram-negative bacteria Salmonella. It typically causes a high fever and abdominal pain. Typhoid fever can be spread by consuming food or... read more ) are given to pregnant women only if they are at substantial risk of developing that particular infection and if the risk of side effects from the vaccine is low.

Some vaccines that are considered safe in pregnant women and are recommended during pregnancy include

Evidence about the safety and effectiveness of COVID-19 vaccination during pregnancy has been growing. These data suggest that the benefits of receiving a COVID-19 vaccine outweigh any known or potential risks of vaccination during pregnancy. (See also CDC: COVID-19 Vaccines While Pregnant or Breastfeeding.)

In August 2023, the US Food and Drug Administration (FDA) approved use of a respiratory syncytial virus (RSV) Respiratory Syncytial Virus (RSV) Infection and Human Metapneumovirus Infection Respiratory syncytial virus infection and human metapneumovirus infection cause upper and sometimes lower respiratory tract infections. Respiratory syncytial virus is a very common cause of... read more vaccine in pregnant individuals between 32 to 36 weeks of pregnancy, with a warning to avoid use prior to 32 weeks (see FDA Approves First Vaccine for Pregnant Individuals to Prevent RSV in Infants).

Medications to lower high blood pressure (antihypertensives Medications High blood pressure (hypertension) is persistently high pressure in the arteries. Often no cause for high blood pressure can be identified, but sometimes it occurs as a result of an underlying... read more ) may be needed by pregnant women who have had high blood pressure before pregnancy or who develop it during pregnancy. Either type of high blood pressure increases the risk of problems for a (such as preeclampsia Preeclampsia and Eclampsia Preeclampsia is new high blood pressure or worsening of existing high blood pressure that is accompanied by excess protein in the urine and that develops after the 20th week of pregnancy. Eclampsia... read more ) and for the fetus (see High Blood Pressure During Pregnancy High Blood Pressure During Pregnancy High blood pressure (hypertension) during pregnancy is classified as one of the following: Chronic hypertension: Blood pressure was high before the pregnancy. Gestational hypertension: Blood... read more ). However, antihypertensives can reduce blood flow to the placenta if they lower blood pressure too rapidly in pregnant women. Pregnant women who have to take these medications are closely monitored.

Several types of antihypertensives, such as angiotensin-converting enzyme (ACE) inhibitors and thiazide diuretics, are usually not given to pregnant women. These medications can cause serious problems in the fetus, such as kidney damage, inadequate growth before birth (growth restriction Small-for-Gestational-Age (SGA) Newborns A newborn who weighs less than 90% of newborns of the same gestational age at birth (below the 10th percentile) is considered small for gestational age. Newborns may be small because their parents... read more ), and birth defects. Spironolactone is also not given to pregnant women. This medication may cause the development of feminine characteristics (feminization) in a male fetus.

Digoxin, used to treat heart failure Heart Failure and some abnormal heart rhythms Overview of Abnormal Heart Rhythms Abnormal heart rhythms (arrhythmias) are sequences of heartbeats that are irregular, too fast, too slow, or conducted via an abnormal electrical pathway through the heart. Heart disorders are... read more , readily crosses the placenta. But at the usual doses, digoxin typically has little effect on the baby before or after birth.

Clinical depression is common during pregnancy and, therefore, antidepressants Medications for depression Depression is a feeling of sadness and/or a decreased interest or pleasure in activities that becomes a disorder when it is intense enough to interfere with functioning. It may follow a recent... read more , particularly certain selective serotonin reuptake inhibitors (SSRIs) such as sertraline, are commonly used during pregnancy. For pregnant women, the benefits of treating depression usually outweigh the risks.

Paroxetine appears to increase the risk of heart birth defects Overview of Heart Defects About one in 100 babies is born with a heart defect. Some are severe, but many are not. Defects may involve abnormal formation of the heart's walls or valves or of the blood vessels that enter... read more . So if a pregnant woman takes paroxetine, echocardiography should be done to evaluate the fetus's heart. However, other SSRIs do not increase this risk.

If a pregnant woman takes antidepressants, the newborn may have withdrawal symptoms (such as irritability and shaking) after delivery. To prevent these symptoms, doctors may gradually reduce the dose of the antidepressant during the third trimester and stop the medication before the baby is born. However, if a woman has significant signs of depression or if symptoms worsen as the dose is reduced, antidepressants should be continued. Depression during pregnancy can lead to postpartum depression Postpartum Depression Postpartum depression is a feeling of extreme sadness and loss of interest in usual activities during the first few weeks or months after delivery. Women who have had depression previously are... read more , which involves a serious change in mood and requires treatment.

Some antiviral medications (such as zidovudine and ritonavir for HIV infection) have been safely used during pregnancy for many years. However, certain antiviral medications may cause problems in the fetus. For example, some evidence suggests that when some HIV regimens with a combination of antiviral medications are given during the first trimester, the risk of cleft lip and palate Cleft Lip and Cleft Palate A cleft is an opening that can form in the lip (cleft lip), roof of the mouth (cleft palate), or both if the tissue does not join together completely during pregnancy. Cleft lip and cleft palate... read more may be increased.

For a pregnant woman with early mild to moderate COVID-19, her treatment team may discuss the risks and benefits and decide whether either nirmatrelvir-ritonavir or remdesivir is appropriate. For pregnant patients hospitalized for COVID-19, use of baricitinib or tocilizumab, may also be considered. Generally, experts recommend that theoretical concerns about the safety of the antiviral medications during pregnancy should not prevent their use in pregnant women.

If a pregnant woman gets influenza, she should seek treatment as soon as possible because treating influenza within 48 hours of when symptoms begin is most effective. However, treatment at any point during the infection reduces the risk of severe complications. No well-designed studies of zanamivir and oseltamivir have been done in pregnant women. However, many studies based on observation indicate that treating pregnant women with zanamivir or oseltamivir does not increase the risk of harmful effects. There is little or no information about the use of other influenza medications during pregnancy.

Acyclovir taken by mouth or applied to the skin, usually to treat herpes simplex virus, appears to be safe during pregnancy.

Medications used to relieve pain during pregnancy Pain relief Labor is a series of rhythmic, progressive contractions of the uterus that gradually move the fetus through the lower part of the uterus (cervix) and birth canal (vagina) to the outside world... read more (such as local anesthetics and opioids) usually cross the placenta and can affect the newborn. For example, they can weaken the newborn's urge to breathe. Therefore, if these medications are needed during labor, they are given in the smallest effective doses.