What is the role of progesterone in pregnant patients undergoing non‑obstetric surgery?

Progesterone in Non-Obstetric Surgery During Pregnancy

Progesterone should be continued during non-obstetric surgery in pregnant patients who are already receiving it for established indications (prior spontaneous preterm birth or short cervical length), but should not be initiated solely because surgery is planned. 1

Clinical Rationale

The available evidence addresses progesterone use in pregnant women undergoing non-obstetric surgery, though the data are limited:

• Progesterone is mentioned as being used in pregnant women undergoing non-obstetric surgery, but no specific randomized controlled trials or guidelines establish its efficacy or necessity in this specific clinical scenario. 1

• The theoretical rationale for continuing progesterone during surgery relates to maintaining uterine quiescence and preventing preterm labor that might be triggered by surgical stress, anesthesia, or postoperative inflammation. 2

Evidence-Based Approach by Clinical Scenario

If Patient Already on Progesterone:

• Continue 17P (17-alpha-hydroxyprogesterone caproate) 250 mg IM weekly if the patient was started on this regimen for prior spontaneous preterm birth between 20-36 6/7 weeks. 3

• Continue vaginal progesterone (90-mg gel or 200-mg suppository daily) if the patient was started on this regimen for short cervical length ≤20 mm detected at ≤24 weeks. 4, 5

• The rationale for continuation is that abrupt discontinuation could theoretically increase preterm birth risk, though no direct evidence supports or refutes this practice. 1

If Patient Not Already on Progesterone:

• Do not initiate progesterone solely for non-obstetric surgery, as there is no evidence supporting its use as prophylaxis against surgery-induced preterm labor. 3

• There is insufficient evidence to recommend progestogens for primary tocolysis even in the setting of threatened preterm labor, making prophylactic use for surgery unsupported. 3

Important Clinical Caveats

• Progesterone has no proven role in active preterm labor or as adjunctive tocolysis with inconsistent evidence at best, so it should not be relied upon to prevent surgery-induced contractions. 3

• Multiple gestations should not receive progesterone for any indication related to preterm birth prevention, including perioperative use. 3, 5

• Timing of surgery does not change progesterone dosing - maintain the established regimen (weekly IM or daily vaginal) without modification. 3

• No specific monitoring beyond standard perioperative obstetric care is required for patients on progesterone undergoing non-obstetric surgery. 4

Practical Management Algorithm

1. Identify if patient has an established indication for progesterone:

   • Prior spontaneous preterm birth 20-36 6/7 weeks → Continue 17P 250 mg IM weekly 3
   • Short cervix ≤20 mm at ≤24 weeks → Continue vaginal progesterone 90-mg gel or 200-mg suppository daily 4, 5

2. If no established indication exists:

   • Do not initiate progesterone for surgery 1
   • Focus on standard perioperative obstetric management 4

3. Postoperatively:

   • Resume or continue progesterone regimen as prescribed 1
   • Monitor for preterm labor using standard clinical assessment, not progesterone levels 3

The key principle is that progesterone use in pregnancy should be driven by established obstetric indications (prior preterm birth or short cervix), not by the surgical procedure itself. 3, 1