In a 23-year-old in the first trimester undergoing emergency appendectomy, which drug has been suggested (but not proven) to be associated with congenital malformations and should be avoided?

In a 23-year-old in the first trimester undergoing emergency appendectomy, which drug has been suggested (but not proven) to be associated with congenital malformations and should be avoided?

• A. Thiopental
• B. Nitrous Oxide
• C. Isoflurane
• D. Diazepam

Answer: (D)

Exposure of a developing fetus to potential teratogens during the first trimester carries a special concern because this is the period of organ formation. Diazepam, a benzodiazepine, has been suggested in some reports to be associated with congenital malformations when exposure occurs in early pregnancy, though a definite causal link has not been proven. Because of this possible risk, it is generally avoided in a first-trimester patient undergoing surgery, especially when alternatives are available. The other drugs listed do not have consistent human data showing they cause congenital malformations in the first trimester, though they can have other risks such as neonatal depression or maternal hemodynamic effects. Thiopental, nitrous oxide, and isoflurane are not the drugs currently implicated as teratogens in early pregnancy, so they are considered more acceptable choices from the teratogenic risk standpoint when clinically appropriate.

Exposure of a developing fetus to potential teratogens during the first trimester carries a special concern because this is the period of organ formation. Diazepam, a benzodiazepine, has been suggested in some reports to be associated with congenital malformations when exposure occurs in early pregnancy, though a definite causal link has not been proven. Because of this possible risk, it is generally avoided in a first-trimester patient undergoing surgery, especially when alternatives are available.

The other drugs listed do not have consistent human data showing they cause congenital malformations in the first trimester, though they can have other risks such as neonatal depression or maternal hemodynamic effects. Thiopental, nitrous oxide, and isoflurane are not the drugs currently implicated as teratogens in early pregnancy, so they are considered more acceptable choices from the teratogenic risk standpoint when clinically appropriate.