Intraoperative Monitoring in Pregnant Women: Safety and Guidelines

Key Safety Principles for Intraoperative Monitoring

The American College of Obstetricians and Gynecologists recommends positioning the patient with left uterine displacement after 20 weeks gestation to prevent aortocaval compression and maintain adequate cardiac output 1, 2, 3
Avoid hypoxemia, hyperoxia, hypotension, acidosis, and hyperventilation as these are critical elements of safe anesthetic management 2, 4, 3

The American College of Obstetricians and Gynecologists states that modern anesthetic agents have not been shown to be teratogenic when used in standard doses 1, 5
Multimodal analgesia including regional analgesia techniques, local anesthetic infiltration, and judicious opioid use is safe in pregnancy 2, 4, 3

The American College of Obstetricians and Gynecologists recommends preoperative and postoperative fetal heart rate detection by Doppler for previable fetuses [<23 weeks] [1, 5, 6]
For viable fetuses [≥23 weeks], simultaneous fetal heart rate tracing and contraction monitoring should be performed before and after surgery 1, 5, 6

Surgery should be performed at an institution with obstetrical, neonatal, and pediatric services 1
Early involvement of an obstetrical anesthesiologist is essential 1
Non-urgent surgery should be postponed until after pregnancy, but pregnancy should not delay urgent surgery 1

Adequate pain relief is essential to prevent reactive preterm contractions 2, 4, 3
Paracetamol is the analgesic of choice for mild to moderate pain during any stage of pregnancy 2, 4, 7, 3
Short-term narcotic use is safe if paracetamol is inadequate 2, 4
Avoid NSAIDs after 28 weeks gestation due to risk of premature ductus arteriosus closure and oligohydramnios 2, 4, 7

Pregnant patients undergoing surgery are at very high risk for venous thromboembolism 2, 4
Screen for venous thromboembolism risk and provide appropriate perioperative prophylaxis 1, 6
Consider pharmacologic prophylaxis with low-molecular-weight heparin 1, 6
Use intra- and postoperative sequential compression devices and encourage early ambulation 1, 6
Corticosteroid administration should be considered for patients with fetuses at viable premature gestational ages 1, 6
Routine prophylactic use of tocolytics is not recommended 1, 5, 6
Obtain consent for emergency cesarean section in case of severe complications when the fetus is viable 2, 4
Have adequately trained staff and equipment readily available 8

The American College of Surgeons recommends auscultating fetal heart tones before and after surgery for previable fetuses, with no intraoperative monitoring necessary 9, 10
For viable fetuses, the American College of Obstetricians and Gynecologists recommends simultaneous electronic fetal heart rate and contraction monitoring before, during, and after surgery to assess fetal well-being and detect uterine contractions 9, 10

The American Academy of Pediatrics suggests discussing active fetal management with intervention in case of maternal or fetal emergencies with parents at the threshold of viability (approximately 24-26 weeks gestation) 9, 10
Survival rates below 28 weeks are less than 75% with high risk of neurological sequelae, while survival rates improve significantly after 32 weeks (95%) with low risk of neurological complications 11, 12

The American Society of Anesthesiologists recommends obtaining informed consent for emergency cesarean section when the fetus is viable, in case of severe maternal or fetal complications 10
Consider preoperative cervical length screening up until 24 weeks if the patient has a history of preterm birth to assess prematurity risk 9, 10
Monitor patients in the perioperative period for signs or symptoms of preterm labor, and provide adequate postoperative pain relief to prevent reactive preterm contractions 9, 10
Paracetamol is the analgesic of choice; short-term narcotics are safe if needed, but avoid NSAIDs after 28 weeks gestation due to risk of premature ductus arteriosus closure 10