Perioperative Use of Cefazolin and Indomethacin for Physical Examination-Indicated Cerclages to Improve Gestational Latency

Obstet Gynecol. 2020 Jun;135(6):1409-1416. doi: 10.1097/AOG.0000000000003874.


Objective: To evaluate gestational latency in individuals who did and did not receive perioperative cefazolin and indomethacin after physical examination-indicated cerclage.

Methods: This is a retrospective cohort study of all pregnant women with a singleton gestation who underwent physical examination-indicated cerclage placement and delivered at Northwestern Memorial Hospital from 2009 to 2018. Physical examination-indicated cerclage was performed in the setting of painless cervical dilation of at least 1 cm between 16 0/7 and 23 6/7 weeks of gestation. After 2014, our practice universally implemented perioperative prophylaxis of cefazolin and indomethacin. Individuals were categorized based on exposure to perioperative prophylaxis. The primary outcome was pregnancy latency at least 28 days after cerclage placement. Secondary outcomes included median latency; median gestational age at delivery; preterm birth before 28 weeks of gestation; preterm prelabor rupture of membranes; chorioamnionitis; and median birth weight. Multivariable analyses were performed, as well as a sensitivity analysis using propensity score matching.

Results: Cerclages were placed in 142 people: 72 (50.7%) received perioperative prophylaxis. Baseline demographics were not significantly different between groups. On multivariable analyses, individuals who received perioperative prophylaxis had a higher incidence of achieving a pregnancy latency at 28 days or more (adjusted relative risk [aRR] 1.21, 95% CI 1.05-1.40). Individuals who received perioperative prophylaxis had a significant improvement in gestational latency (+17.8 days, 95% CI 1.4-34.2 days) and birth weight (+489.8 g, 95% CI 64.6-915.0 g), with no differences in other outcomes. On sensitivity analysis, individuals receiving perioperative prophylaxis had a higher incidence of achieving a pregnancy latency at 28 days or more, (aRR 1.17, 95% CI 1.01-1.36) with no differences in other outcomes.

Conclusion: Perioperative use of cefazolin and indomethacin prophylaxis during physical examination-indicated cerclage placement is associated with a significant prolongation in gestational latency without an increase in incidence of chorioamnionitis.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Adult
  • Anti-Bacterial Agents / administration & dosage*
  • Anti-Inflammatory Agents, Non-Steroidal / administration & dosage
  • Anti-Inflammatory Agents, Non-Steroidal / therapeutic use*
  • Antibiotic Prophylaxis
  • Cefazolin / administration & dosage*
  • Cerclage, Cervical*
  • Cervix Uteri / pathology
  • Dilatation, Pathologic
  • Female
  • Gestational Age
  • Humans
  • Indomethacin / administration & dosage
  • Indomethacin / therapeutic use*
  • Linear Models
  • Obstetric Labor, Premature / prevention & control*
  • Physical Examination
  • Pregnancy
  • Retrospective Studies
  • Uterine Cervical Incompetence / surgery


  • Anti-Bacterial Agents
  • Anti-Inflammatory Agents, Non-Steroidal
  • Cefazolin
  • Indomethacin