Pregnancy Safety Guidelines
A Guide to Drug Safety in Pregnancy - A US FDA Classification of Risk of Drug Use in Pregnancy.
As part of our ongoing efforts to improve the quality and comprehensiveness of drug information, we have included a simple guideline for drug safety during pregnancy. No risk factor for drug safety during pregnancy can be presented for the product without factor grading. Most temporary preparations do not have a pregnancy section because systemic absorption is generally considered minimal unless the use is extensive, intensive, or prolonged.
Definition of risk factors
These definitions are used by the United States Food and Drug Administration (FDA). These categories do not refer to the increasing progression of risk from A to X. Drugs are classified based on risk and benefit versus benefit of adverse effects on reproduction and development. Drugs in D, X, and in some cases C may create similar risks but may be classified differently based on different risk vs. benefit considerations.
For more information, please visit www.fda.gov.
Category A: (Human studies show no risk)-Controlled studies in women fail to show risk for the fetus in the first trimester (and no evidence of risk in the next trimester), and the likelihood of fetal harm remains remote.
Category B: (No evidence of risk in studies)-Either animal-breeding studies did not show fetal risk but there were no controlled studies in pregnant women or animal-breeding studies showed an adverse effect (excluding fertility reduction) that was not confirmed in controlled studies in women in the first trimester (and no evidence of risk in the next trimester).
Category C: (Risk cannot be ruled out)-Either animal studies have shown adverse effects on the fetus (teratogenic or fetal or other) and there are no controlled studies in women or studies in women and animals. Medications should only be given if the potential benefits support the potential risk to the fetus.
Category D: (Positive evidence of risk)-There is positive evidence of human fetal risk, but the benefits of using it in pregnant women may be acceptable despite the risk (e.g., if medication is needed in life-threatening situations or for a serious illness for which safe medication is not possible or ineffective).
Category X: (Contraindicated in pregnancy)-Studies on animals or humans have shown fetal abnormalities or evidence of fetal risk based on human experience or both, and the risk of drug use in pregnant women is clearly greater than any potential benefit. The drug is contraindicated in women who are pregnant or may be pregnant.
A group of drugs with pregnancy warnings from expert committees or regulatory agencies, but not prescribed by the US FDA Pregnancy Category, are classified as Category Z.
Category Z: There are studies, recommendations, or warnings from the relevant expert committee and/or regulatory body for the use of this medicine during pregnancy. Read the text along with the generic monograph for more information.
Category A Drugs
- Thiamine, Pyridoxine, Folic acid
- Docusate, Senna, Bisacodyl
- Dextromethorphan
- Doxylamine
- Levothyroxine
- Isoniazid
Category B Drugs
Antibiotics
- Penicillin V, Penicillin G Benzathine, Amoxicillin, Amoxicillin/Clavulanate, Oxacillin, Ampicillin, Ampicillin/Sulbactam, Ticarcillin/Clavulanate, Dicloxacillin, Cloxacillin, Nafcillin
- Ceftriaxone, Cephalexin, Cefazolin, Cefepime, Cefuroxime, Ceftaroline fosamil, Cefdinir, Cefadroxil, Cefpodoxime, Cefprozil, Ceftolozane/tazobactam, Cefditoren
- Clindamycin, Azithromycin, Erythromycin, Fidaxomicin, Spiramycin
- Metronidazole
- Daptomycin
- Aztreonam, Meropenem, Ertapenem, Doripenem
- Nitrofurantoin, Fosfomycin
- Mupirocin
- Quinupristin/dalfopristin
Other Antimicrobials
- Acyclovir, Famciclovir
- Valacyclovir
- Amphotericin B
- Clotrimazole (topical, vulvovaginal)
- Terbinafine
- Mefloquine
- Permethrin
- Emtricitabine/tenofovir (Truvada)
- Nitazoxanide
- Praziquantel
- Raxibacumab
Antiemetics and other GI medications
- Metoclopramide
- Ondansetron
- Dimenhydrinate
- Famotidine
- Lansoprazole, Pantoprazole
- Lactulose, Psyllium
- Loperamide
- Dicyclomine
- Ursodiol
- Sucralfate
Analgesics and other neuro/psych meds
- Acetaminophen
- Ketamine
- Meperidine
- Cyclobenzaprine
- Indomethacin
- Meclizine
- Clozapine
- Benztropine
- Buspirone
- Methylphenidate
Cardiovascular Medications
- Hydrochlorothiazide
- Fenoldopam
- Torsemide, Ethacrynic acid, Amiloride
- Epoprostenol (prostacyclin)
- Sildenafil
- Dobutamine
- Sotalol
Antiplatelet and Anticoagulants
- Clopidogrel, Prasugrel
- Eptifibatide
- Ticlopidine
- Tirofiban
- Apixaban
- Argatroban, Bivalirudin
- Fondaparinux
- Enoxaparin
Antidotes
- EDTA
- Levocarnitine
- Cyproheptadine
- Idarucizumab
- N-acetylcysteine
Miscellaneous
- Ipratropium, Budesonide
- Ranitidine, Cimetidine
- Metformin
- Oxybutynin, Tamsulosin, Phenazopyridine
- Bromocriptine
- Glycopyrrolate
- Montelukast
- Desmopressin
- Glucagon
- Prilocaine
- Propofol
- Sodium polystyrene sulfonate
- Sulfasalazine
Category C Drugs
Includes most medications not listed elsewhere hereCategory D Drugs
Antimicrobials
- Gentamicin, Neomycin, Amikacin, Streptomycin, Kanamycin
- Trimethoprim-sulfamethoxazole
- Doxycycline, Minocycline, Tetracycline, Tigecycline
- Fluconazole, Voriconazole
- Primaquine, Hydroxychloroquine
AEDs and other neuro/psych meds
- Phenytoin, Fosphenytoin
- Carbamazepine
- Midazolam, Alprazolam, Clonazepam, Diazepam
- Phenobarbital
- Magnesium sulfate (despite being drug-of-choice for eclampsia!)
- Lithium
- Topiramate
- Pentobarbital
Cardiovascular
- Amiodarone
- Atenolol
- Lisinopril, Captopril, Enalapril, Benazepril
- Losartan, Valsartan
- Aspirin (3rd trimester)
- Edoxaban
- Warfarin
Miscellaneous
- Cortisone, Flunisolide
- Mycophenolate mofetil
- Penicillamine
- Methimazole, Propylthiouracil, Potassium iodide
- Hydroxyurea
- Zoledronate Bismuth subsalicylate (3rd trimester only)
- Cyclophosphamide
- Ibuprofen (3rd trimester only, otherwise category C)
- Meloxicam (if >30wks, otherwise category C)
- Tamoxifen
Category X Drugs
- Valproate
- Methotrexate
- Ribavirin
- Triazolam
- Bosentan
- Aliskiren
- Emergency contraception: Levonorgestrel, Ulipristal
- Griseofulvin
- Methylene blue
- Oxytocin
- Riociguat
- Isotretinoin