Table 1.

The FDA’s classification of drugs used in pain management regarding pregnancy risk.

Classification	Definition	Examples	References
Category A	Controlled studies in pregnant women have not shown a risk to the fetus.	-
Category B	Animal studies have not shown toxic effects on the fetus, but there are no controlled clinical trials in humans. Animal studies have shown toxic effects but have not been confirmed in studies in pregnant women.	Acetaminophen	[52,53,54,55]
		Oxycodone
		Lidocaine
		Dexamethasone
Category C	Animal studies have shown teratogenic risk, but no controlled studies have been performed in pregnant women.	Piroxicam	[56,57,58,59,60,61,62,63,64,65]
		Codeine
		Hydrocodone
		Diclofenac
		Ibuprofen
		Naloxone
		Ketoprofen
		Celecoxib
		Naproxen
		Tramadol
Category D	Positive evidence of fetal risk but their use is accepted, the benefit of the mother outweighs the risk of the fetus.	Acetyl salicylic acid	[66]
Category X	Studies in both animals and humans have shown fetal malformations or no evidence. The risks outweigh the benefits, they are contraindicated in pregnancy.	Ergot derivatives	[67]