Anesthesia for Nonobstetric Surgery During Pregnancy

Approximately 1% to 2% of women undergo nonobstetric surgery during pregnancy. Purely elective surgical procedures are relatively contraindicated in pregnancy and should be postponed until 6 weeks postpartum. If a surgical procedure must be performed, the second trimester is the preferred time. The objectives in the anesthetic management include the following:

1. Maternal safety. Induction and emergence from general anesthesia are more rapid in pregnant patients due to the increase in minute ventilation and decrease in FRC. Uterine displacement to minimize aortocaval compression should be considered as early as the second trimester. During any anesthetic, oxygen transport to the placenta must be maintained.
2. Teratogenicity. In 2016, the U.S. Food and Drug administration released a Drug Safety Communication warning that “repeated or lengthy use of general anesthetic or sedation drugs during surgeries or procedures in children younger than 3 years or in pregnant women during their third trimester may affect the development of children’s brains.” However, no data from pregnant women were included among the clinical studies cited, and a series of subsequent studies showed no evidence of an effect on neurodevelopmental outcomes in young children exposed to anesthesia. Nitrous oxide may interfere with DNA synthesis and is often avoided by practitioners in the first and second trimesters.
3. Fetal well-being. Pregnant women who undergo surgery during their pregnancies have a higher rate of preterm labor. Laparoscopy is not associated with a higher rate of adverse pregnancy outcomes.
4. Reversal of residual neuromuscular block. The use of the combination of neostigmine and glycopyrrolate might expose the fetus to unopposed neostigmine and cause fetal bradycardia, as the placenta is more permeable to neostigmine than glycopyrrolate.