Azithromycin for Cerclage Prophylaxis

Evaluating Azithromycin Prophylaxis and Mycoplasma Prevalence in High-Risk Pregnancies Requiring Cerclage: A Prospective Cohort Study

The primary goal is to assess the effectiveness in pregnancy prolongation utilizing azithromycin at the time of transvaginal cervical cerclage placement.

Study Overview

• Status: Not yet recruiting
• Conditions: Cervical Insufficiency
• Intervention / Treatment: Drug: Azithromycin Prophylaxis; Drug: Cefazolin; Drug: Azithromycin Placebo

Detailed Description

The overall objective of this prospective two-arm randomized study is to (1) randomize subjects to azithromycin surgical prophylaxis versus placebo, plus the standard of care - cefazolin, at the time of cerclage placement and evaluate the impact on preterm delivery <37 weeks, <34 weeks and <28 weeks and (2) determine the prevalence of mycoplasma species in cerclage patients. Pregnant women who are candidates for cervical cerclage will be enrolled and divided into two cohorts (approximately 40 per group): (1) Cerclage + Azithromycin prophylaxis (treatment group), and (2) Cerclage without azithromycin prophylaxis (control group). Both groups will receive otherwise usual care.

• Study Type: Interventional
• Enrollment (Estimated): 80
• Phase: Phase 4

Contacts and Locations

• Study Contact: Name: Rachel Harrison, MD; Phone Number: 616-218-2892; Email: rachel.harrison@aah.org

Study Locations

• United States
  • Illinois
    • Oak Lawn, Illinois, United States, 60453
      • Advocate Christ Medical Center
      • Contact: Rachel Harrison, MD; Phone Number: 616-218-2892; Email: rachel.harrison@aah.org
    • Park Ridge, Illinois, United States, 60068
      • Advocate Lutheran General Hospital

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Singleton gestation at 16+0 to 23+6 weeks of gestational age at the time of enrollment
• Indication for transvaginal cerclage placement
• Intact amniotic membranes

Exclusion Criteria:

• Evidence of active infection or chorioamnionitis at presentation
• Preterm prelabor rupture of membranes (PPROM)
• Multiple gestation
• HIV positive status
• Known severe allergy or contraindication to macrolide antibiotics (azithromycin or erythromycin)
• Use of systemic antibiotics within the past 7 days (to avoid altered baseline vaginal microbiome)
• Major fetal anomaly or known chromosomal abnormalities that significantly affect viability
• Any maternal condition that would ethically preclude expectant management of pregnancy irrespective of cerclage

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Quadruple

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Cerclage and Azithromycin Prophylaxis; women at high risk for mid-trimester loss or early preterm birth who choose to undergo a cerclage as part of standard care recommendations	Drug: Azithromycin Prophylaxis; 500 mg of IV azithromycin prior to cerclage placement in the operating room or pre-operative area.; Drug: Cefazolin; All participants will receive standard of care cefazolin. First dose is to be given preoperatively, and the next two doses to be given 8 and 16 hours postoperatively. Participants weighing less than 100 kg will receive 2 g cefazolin, and those weighing 100 kg or more will receive 3 g cefazolin.
Active Comparator: Cerclage Without Azithromycin Prophylaxis; women at high risk for mid-trimester loss or early preterm birth who choose to undergo a cerclage as part of standard care recommendations	Drug: Cefazolin; All participants will receive standard of care cefazolin. First dose is to be given preoperatively, and the next two doses to be given 8 and 16 hours postoperatively. Participants weighing less than 100 kg will receive 2 g cefazolin, and those weighing 100 kg or more will receive 3 g cefazolin.; Drug: Azithromycin Placebo; normal saline placebo IV infusion prior to cerclage placement in the operating room or pre-operative area

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Latency from Cerclage to Delivery	Number of days from cerclage to delivery	Up to Week 42
Gestational Age at Delivery	Gestational age at delivery measured in weeks and days	Up to Week 42

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Incidence of Chorioamnionitis	number of participants with chorioamnionitis	Up to Week 42
Incidence of Preterm Premature Birth	Number of participants that experienced preterm premature birth	28 weeks gestation, 34 weeks gestation, 37 weeks gestation
Incidence of Preterm Premature Rupture of Membranes	Number of participants that experienced preterm premature rupture of membranes	up to 37 weeks gestation
Complications from Cerclage	Number participants that experienced complications from cerclage	Up to Week 42
Prevalence of Mycoplasma Infection or Colonization	Number of participants with prevalence of mycoplasma infection or colonization	Up to Week 42

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Neonate Birth Weight	weight of neonate at birth	day of delivery
Apgar Scores	The Apgar score is a standardized test used to rapidly assess a newborn's health immediately after birth. It is evaluated at 1 minute (to see how the baby handled delivery) and 5 minutes (to check how the baby is adapting to life outside the womb). Total score range is 0-10 with a higher score indicating newborn is adapting well to life outside the womb.	1 minute post delivery, 5 minutes post delivery
Number of NICU Admissions	number of neonates admitted to NICU after delivery	day of delivery
Length of NICU Admission	number of days neonates spent in NICU	up to month 12
Neonate Survival Rate	percent of neonate survival	up to month 12
Composite Neonate Morbidity	composite neonatal morbidity is a yes/no outcome that is considered yes if any of the adverse outcomes are positive	up to month 12

Collaborators and Investigators

• Sponsor: Wake Forest University Health Sciences
• Investigators: Principal Investigator: Rachel Harrison, MD, Advocate Christ Medical Center

Study record dates

Study Major Dates

• Study Start (Estimated): June 1, 2026
• Primary Completion (Estimated): June 1, 2028
• Study Completion (Estimated): December 1, 2028

Study Registration Dates

• First Submitted: May 20, 2026
• First Submitted That Met QC Criteria: May 20, 2026
• First Posted (Actual): May 27, 2026

Study Record Updates

• Last Update Posted (Actual): May 27, 2026
• Last Update Submitted That Met QC Criteria: May 20, 2026
• Last Verified: May 1, 2026

More Information

Terms related to this study

• Keywords: short cervix; cerclage; pregnancy prolongation
• Additional Relevant MeSH Terms: Urogenital Diseases; Genital Diseases; Female Urogenital Diseases; Female Urogenital Diseases and Pregnancy Complications; Pregnancy Complications; Uterine Diseases; Genital Diseases, Female; Uterine Cervical Diseases; Abortion, Habitual; Abortion, Spontaneous; Uterine Cervical Incompetence; Sulfur Compounds; Organic Chemicals; Heterocyclic Compounds; Heterocyclic Compounds, 2-Ring; Heterocyclic Compounds, Fused-Ring; Amides; beta-Lactams; Lactams; Cephalosporins; Thiazines; Cefazolin
• Other Study ID Numbers: IRB00131410

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: Yes
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No