Anesthesiology APPLIED Exam › Obstetric anesthesia

Non-obstetric surgery during pregnancy

Obstetric anesthesia·~4 min read· Physician-reviewed✓ Sourced · 3

Stem

A 29-year-old woman, 74 kg, at 27 weeks' gestation presents with 18 hours of right-sided abdominal pain, fever and leukocytosis; ultrasound and MRI confirm acute appendicitis. She is scheduled for urgent laparoscopic appendectomy this evening. She is otherwise healthy, the pregnancy has been uncomplicated, and the fetal heart rate is 145 bpm with no contractions. The hospital has a labor floor and a neonatal ICU.

Question

How will you plan and conduct her anesthetic?

Ideal answer

HeadlineMother first, then uteroplacental perfusion and fetal oxygenation; I do not delay this operation because she is pregnant.¹ I plan with her obstetrician: at 27 weeks the fetus is viable.

Agree the fetal plan before induction. Fetal heart rate and contraction monitoring before and after, whether to monitor during, her consent to cesarean for fetal indications, and whether steroids for fetal lung maturity are indicated.¹
Aspiration prophylaxis and left uterine displacement. Aortocaval compression lowers cardiac output and placental flow.²
Careful preoxygenation, rapid sequence, smaller tube, video laryngoscope. Her FRC is reduced and oxygen consumption higher.² Then a standard balanced anesthetic.
Insufflation 10–15 mmHg, CO2 at her pregnant normal. Followed by capnography;³ phenylephrine promptly for hypotension.
Pneumatic compression, early ambulation, no prophylactic tocolysis. Then multimodal analgesia and fetal heart rate and contraction monitoring in recovery.³^,1

Breaking down the answer

Never delay necessary surgery — ACOG: no pregnant woman should be denied or delayed medically necessary surgery in any trimester; elective surgery waits until after delivery.¹ Perforated appendicitis is the bigger threat to the fetus than the anesthetic.
Drug fear is misplaced — no anesthetic in current use has been shown to be teratogenic in humans.¹
Fetal monitoring follows viability — previable: Doppler fetal heart rate before and after; viable: electronic fetal heart rate and contraction monitoring before and after.¹ Intraoperative monitoring only when viable, physically possible, an obstetric surgeon available, emergency cesarean consented, and surgery can be interrupted.¹
Physiology drives the technique — cardiac output rises about 50%, FRC falls about 20%, and oxygen consumption rises, so she desaturates fast and is vulnerable to caval compression.²
Laparoscopy is acceptable at any gestation — SAGES gives a strong recommendation for laparoscopy in any trimester, left lateral positioning after the first trimester, and capnography during the case.³
Tocolytics only for labor — SAGES recommends against prophylactic use but supports it when signs of preterm labor appear.³ Site matters too: neonatal and pediatric services on hand, obstetric provider informed.¹

Follow-up question

Forty minutes in, with the abdomen insufflated, the obstetric nurse monitoring the fetus reports a sustained fetal heart rate of 95 bpm. Maternal blood pressure is 88/46 mmHg and end-tidal CO2 is 44 mmHg.

What do you do?

Follow-up answer

HeadlineFetal bradycardia from reduced uteroplacental perfusion, likely maternal hypotension and hypercarbia; I tell the surgeon to stop and release the pneumoperitoneum and tell the obstetrician.

I increase left uterine displacement, give phenylephrine and fluid to restore her baseline pressure, go to 100% oxygen, and raise minute ventilation to bring her CO2 back to her usual pregnant level. I check for bleeding, a high-pressure insufflation reading, or too much anesthetic depth. If the rate recovers, the surgeon resumes at a lower pressure; if not, the obstetric team decides on delivery, which is why consent and cesarean readiness were in my plan.¹ Afterward, I monitor for contractions and treat preterm labor if it appears.³

Pitfalls that cost points

Postponing urgent surgery to the second trimester or until delivery.
Saying "I would monitor the fetus" without stating who interprets the tracing and what you will do with it.
Hyperventilating to a nonpregnant normal end-tidal CO2 or ignoring CO2 during laparoscopy.

Rapid-fire

Q: Do anesthetic drugs cause birth defects? A: No currently used anesthetic agent has been shown to be teratogenic in humans.¹

Q: What fetal monitoring do you use for a previable fetus? A: A Doppler fetal heart rate before and after the procedure is generally sufficient.¹

Q: When do you give corticosteroids? A: Consider them for fetal benefit when the fetus is viable but premature.¹

Q: What VTE prophylaxis? A: Screen for VTE risk; SAGES recommends pneumatic compression and early ambulation.¹^,3

Q: When does aortocaval compression matter? A: It can occur from the end of the first trimester and typically after 20 weeks.²

Numbers to know

Item	Value
Cardiac output increase	~50%²
FRC decrease	~20%²
Insufflation pressure	10–15 mmHg³
Uterine displacement	After the first trimester³

Sources

1.Nonobstetric Surgery During Pregnancy (Committee Opinion No. 775) · ACOG, 2019 · acog.org
2.Changes in Maternal Physiology During Pregnancy (Update in Anaesthesia 21) · WFSA · resources.wfsahq.org
3.Guidelines for the Diagnosis, Treatment, and Use of Laparoscopy for Surgical Problems during Pregnancy · SAGES · sages.orgGuidelines 9, 10, 12, 13, 14, 21 and 22.

Facts on this page were checked against these sources on Oct 15, 2026. Guidelines change; confirm doses against current institutional protocols.