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Some Drugs That Can Cause Problems During Pregnancy*

Some Drugs That Can Cause Problems During Pregnancy*

Examples

Possible Problems

Antianxiety drugs

When the drug is taken late in pregnancy, very slow breathing or a withdrawal syndrome (causing irritability, shaking, and exaggerated reflexes) in the newborn

Antibiotics

Damage to the fetus's ear (ototoxicity), resulting in deafness

Possibly gray baby syndrome (a serious and often fatal disorder)

Possibility of bone and joint abnormalities (seen only in animals)

In women or fetuses with G6PD deficiency, the breakdown of red blood cells

In women or fetuses with G6PD deficiency, the breakdown of red blood cells

With sulfasalazine, much less risk of problems

In women or fetuses with G6PD deficiency, the breakdown of red blood cells

Slowed bone growth, permanent yellowing of the teeth, and increased risk of cavities in the child

Occasionally, liver failure in the pregnant woman

Factor Xa inhibitors such as rivaroxaban, apixaban, or edoxaban

Possible risk of bleeding in the pregnant woman or fetus

Heparin

Warfarin

Birth defects Overview of Birth Defects read more , intellectual disability, cataracts, and other problems with the eyes in the fetus

Bleeding problems in the fetus and the pregnant woman

Antidepressants

Bupropion

Harmful effects seen in animals, but conflicting evidence for risk of birth defects in newborns

Citalopram

When citalopram is taken during the 1st trimester, increased risk of birth defects (particularly heart defects)

When citalopram is taken during the 3rd trimester, discontinuation syndrome (which includes dizziness, anxiety, irritability, fatigue, nausea, chills, and muscle aches) and persistent pulmonary hypertension of the newborn Persistent Pulmonary Hypertension of the Newborn Persistent pulmonary hypertension of the newborn is a serious disorder in which the arteries to the lungs remain narrowed (constricted) after delivery, thus limiting the amount of blood flow... read more (the arteries to the lungs remain narrowed after delivery, limiting blood flow to the lungs and thus the amount of oxygen in the bloodstream)

Escitalopram

When escitalopram is taken during the 3rd trimester, discontinuation syndrome and persistent pulmonary hypertension of the newborn

Fluoxetine

When fluoxetine is taken during the 3rd trimester, discontinuation syndrome and persistent pulmonary hypertension of the newborn

Paroxetine

When paroxetine is taken during the 1st trimester, increased risk of birth defects, particularly heart defects

When the drug is taken during the 3rd trimester, discontinuation syndrome and persistent pulmonary hypertension of the newborn

Sertraline

When sertraline is taken during the 3rd trimester, discontinuation syndrome and persistent pulmonary hypertension of the newborn

Venlafaxine

When venlafaxine is taken during the 3rd trimester, discontinuation syndrome

Antiemetic drugs (used to relieve nausea)

Doxylamine and pyridoxine (vitamin B6)

No increased risk of birth defects

Meclizine

Birth defects seen only in animals

Ondansetron

No conclusive evidence of birth defects in animals

Promethazine

No conclusive evidence birth defects in animals

Possible risk of bleeding in the newborn

Antifungal drugs

Amphotericin B

No increased risk of birth defects, but no well-designed studies done in pregnant women

Fluconazole

No increased risk of birth defects after a single low dose

When high doses are taken for most or all of the 1st trimester, increased risk of birth defects, such as abnormalities in the heart, face, skull, ribs, and limbs

Miconazole

No increased risk of birth defects when applied to the skin

When taken by mouth, side effects in animal studies

When inserted into the vagina, no increased risk of birth defects

Terconazole

No increased risk of birth defects

When inserted into the vagina, no increased risk of birth defects

Antihistamines

Loratadine

Meclizine

Birth defects in rodents but no proof of this effect in humans

Antihypertensive drugs

With spironolactone, possible development of feminine characteristics in male fetuses

With eplerenone, no increased risk of birth defects in animals, but no well-designed studies done in pregnant women

When the drugs are taken late in pregnancy, kidney damage in the fetus, a reduction in the amount of fluid around the developing fetus (amniotic fluid Problems With Amniotic Fluid Amniotic fluid is the fluid that surrounds the fetus in the uterus. The fluid and fetus are contained in membranes called the amniotic sac. Problems with amniotic fluid include Too much amniotic... read more ), and defects of the face, limbs, and lungs

Low blood pressure in the mother

When calcium channel blockers are taken during the 1st trimester, possibly birth defects of the fingers and/or toes

When calcium channel blockers are taken later in pregnancy, inadequate growth of the fetus

A decrease in the levels of oxygen, sodium, and potassium and in the number of platelets in the fetus's blood

Inadequate growth of the fetus

Antipsychotic drugs

Haloperidol

Harmful effects in animals

When haloperidol is taken during the 1st trimester, possibly birth defects in the limbs

When haloperidol is taken during the 3rd trimester, increased risk of the following:

  • Repetitive, involuntary movements (extrapyramidal symptoms)

  • Restlessness, irritability, shaking, difficulty breathing, and feeding problems (symptoms of drug withdrawal) in the newborn because at birth, passage of the drug from the mother through the placenta stops

Lurasidone

No evidence of harmful effects in animals

When lurasidone is taken during the 3rd trimester, increased risk of the following:

  • Repetitive, involuntary movements

  • Restlessness, irritability, shaking, difficulty breathing, and feeding problems (symptoms of drug withdrawal) in the newborn because at birth, passage of the drug from the mother through the placenta stops

Olanzapine

Harmful effects in animals

When olanzapine is taken during the 3rd trimester, increased risk of the following:

  • Repetitive, involuntary movements

  • Restlessness, irritability, shaking, difficulty breathing, and feeding problems (symptoms of drug withdrawal) in the newborn because at birth, passage of the drug from the mother through the placenta stops

Risperidone

Harmful effects in animals

No evidence of increased risk of birth defects, but no well-designed studies done in pregnant women

When risperidone is taken during the 3rd trimester, increased risk of the following:

  • Repetitive, involuntary movements

  • Restlessness, irritability, shaking, difficulty breathing, and feeding problems (symptoms of drug withdrawal) in the newborn because at birth, passage of the drug from the mother through the placenta stops

Carbamazepine

Increased risk of birth defects, including neural tube defects (such as spina bifida)

Bleeding problems in the newborn (hemorrhagic disease of the newborn), which can be prevented if pregnant women take vitamin K by mouth every day for a month before delivery or if the newborn is given an injection of vitamin K soon after birth

Lamotrigine

No substantial increased risk of birth defects

Levetiracetam

Minor bone abnormalities seen in animals

No substantial increased risk in people

Phenobarbital

Increased risk of birth defects, including neural tube defects (such as spina bifida)

Bleeding problems in the newborn

Phenytoin

Increased risk of birth defects (such as cleft lip and heart defects)

Bleeding problems in the newborn

Trimethadione

High risk of birth defects (such as cleft palate and defects of the heart, skull, face, hands, and abdomen)

Risk of a miscarriage

Valproate

Chemotherapy drugs

Actinomycin

Possibility of birth defects (seen only in animals)

Busulfan

Birth defects such as underdevelopment of the lower jaw, cleft palate, abnormal development of the skull bones, spinal defects, ear defects, and clubfoot

Chlorambucil

Same as those for busulfan

Colchicine

Possibility of birth defects (seen in animals)

Abnormalities in sperm in sons

Cyclophosphamide

Same as those for busulfan

Doxorubicin

Heart problems, depending on the dose taken

Birth defects

Mercaptopurine

Same as those for busulfan

Methotrexate

Same as those for busulfan

Vinblastine

Possibility of birth defects (seen only in animals)

Vincristine

Possibility of birth defects (seen only in animals)

Mood-stabilizing drug

When lithium is taken during the 1st trimester, increased risk of birth defects (mainly of the heart)

Aspirin and other salicylates

Ibuprofen

Naproxen

When the drugs are taken late in pregnancy, a reduction in the amount of fluid around the developing fetus

When low doses of aspirin are taken, no significant risk of birth defects

Buprenorphine

No evidence of increased risk of birth defects but may have other harmful effects on the fetus or newborn

Restlessness, irritability, shaking, difficulty breathing, and feeding problems (symptoms of drug withdrawal) in the newborn because at birth, passage of the drug from the mother through the placenta stops

Codeine

Hydrocodone

Hydromorphone

Meperidine

Morphine

Restlessness, irritability, shaking, difficulty breathing, and feeding problems (symptoms of drug withdrawal) in the newborn, possibly occurring 6 hours to 8 days after birth

If high doses are given in the hour before delivery, possibly drowsiness and a slowed heart rate in the newborn

Methadone

Restlessness, irritability, shaking, difficulty breathing, and feeding problems (symptoms of drug withdrawal) in the newborn

Chlorpropamide

Glyburide

Metformin

Tolbutamide

A very low blood sugar level in the newborn

Sex hormones

Danazol

When this drug is taken very early in pregnancy, masculinization of a female fetus’s genitals, sometimes requiring surgery for correction

Synthetic progestins (but not the low doses used in oral contraceptives)

Same as those for danazol

Skin treatment

Isotretinoin

Birth defects, such as heart defects, small ears, and hydrocephalus (sometimes called water on the brain)

Intellectual disability

Risk of miscarriage

Thyroid drugs

Methimazole

An enlarged or underactive thyroid gland in the fetus

Scalp defects in the newborn

Propylthiouracil

An enlarged or underactive thyroid gland in the fetus

Liver damage in the mother

Radioactive iodine

Destruction of the thyroid gland in the fetus

When the drug is given near the end of the 1st trimester, a very overactive and enlarged thyroid gland in the fetus

Triiodothyronine

An overactive and enlarged thyroid gland in the fetus

Vaccines

COVID-19 vaccines

Limited data about the safety of the COVID-19 vaccines in pregnant women

Recommended that pregnant and breastfeeding women discuss the risks and benefits of vaccination with their health care practitioner

Potential infection of the placenta and developing fetus

Potential but unknown risks

Other drugs

Corticosteroids

Possibly a cleft lip when these drugs are taken during the 1st trimester

Hydroxychloroquine

No increased risks at the doses usually used

Isoniazid

Possible harmful effects on the liver or damage to the peripheral nerves (causing abnormal sensations and/or weakness)

Pseudoephedrine (a decongestant)

Narrowing of the blood vessels in the placenta, possibly reducing the amount of oxygen and nutrients the fetus receives and thus resulting in inadequate growth before birth

Vitamin K

In women or fetuses with G6PD deficiency, destruction of red blood cells (hemolysis)

* Unless medically necessary, drugs should not be used during pregnancy. However, drugs can be essential to maintain the health of the pregnant woman and the fetus. In such cases, a woman should talk with her health care practitioner about the risks and benefits of the prescription drugs she is taking before she stops taking them. She should not stop taking them on her own.

† Opioids are used to relieve pain. However, they also cause an exaggerated sense of well-being, and if used too much, they can cause dependence and addiction.

‡ Insulin is usually preferred.

G6PD = glucose-6-phosphate dehydrogenase.