When should nitrous oxide be avoided in pregnant patients?

Nitrous oxide should be avoided during the first trimester of pregnancy primarily due to concerns about potential teratogenic effects during a critical period of fetal development. The first trimester is when embryonic organs are forming, and exposure to certain agents, including nitrous oxide, can pose risks. Research has indicated that exposure during this early stage could lead to complications, including neural tube defects.

The other options do not align with current guidelines or research findings. While labor is a common time for the use of nitrous oxide, using it throughout the entire pregnancy or specifically after the second trimester does not reflect the nuanced understanding of fetal development risks. Thus, recognizing the first trimester as the most critical period for avoiding nitrous oxide helps ensure the safety of both the pregnant individual and the developing fetus.