Fetal development in mice exposed to isoflurane

Area of Science:

• Developmental Toxicology
• Anesthesiology
• Teratology

Background:

• Anesthetic agents are widely used in pregnant patients.
• Assessing the safety of anesthetic exposure during critical developmental periods is crucial.
• Previous studies have indicated potential risks associated with certain anesthetics.

Purpose of the Study:

• To evaluate the developmental toxicity of varying concentrations of isoflurane in pregnant Swiss/Webster mice.
• To determine dose-dependent effects of isoflurane on fetal development.

Main Methods:

• Pregnant Swiss/Webster mice were exposed to different concentrations of isoflurane (0.006%, 0.06%, 0.6%) for 4 hours daily from day 6 to 15 of gestation.
• Control groups received no isoflurane exposure.
• Fetal outcomes including weight, skeletal ossification, and presence of malformations were assessed.

Main Results:

• Exposure to 0.006% and 0.06% isoflurane did not result in adverse developmental effects.
• Exposure to 0.6% isoflurane significantly decreased fetal weight and skeletal ossification.
• A notable increase in minor hydronephrosis, renal pelvic cavitation, and cleft palate (12.1% of fetuses) was observed at the 0.6% concentration.

Conclusions:

• Isoflurane exposure at a light anesthetic concentration (0.6%) during pregnancy is associated with significant developmental toxicity in mice.
• The observed teratogenic effects, particularly cleft palate, were more frequent compared to control groups and other anesthetic agents.
• These findings highlight the potential risks of isoflurane exposure during sensitive periods of embryonic and fetal development.