# Adjunctive Azithromycin Prophylaxis for Scheduled/Prelabor Cesarean Delivery

> **NIH NIH U01** · GEORGE WASHINGTON UNIVERSITY · 2024 · $3,614,140

## Abstract

ABSTRACT
We propose a large randomized clinical trial within the MFMU Network designed to evaluate the benefits and
safety of azithromycin-based prophylaxis (azithromycin plus standard cephalosporin) relative to standard
cephalosporin alone prior to surgical incision to prevent post-cesarean (CD) infection. In contrast to
cephalosporin, azithromycin is effective against additional pathogens encountered in polymicrobial post-CD
infections. We demonstrated adjunctive azithromycin, compared to standard prophylaxis, reduced maternal
infections by 50% with remarkable cost-savings in unscheduled CDs. The American College of Obstetricians
and Gynecologists (ACOG) now recommends routine use in unscheduled CDs. Our preliminary studies suggest
azithromycin may also lower infection risk in the 40-50% that are scheduled/pre-labor CDs, but there are safety
concerns regarding the adverse neonatal and long-term microbiome-mediated effects of perinatal exposure.
During the project period of 5 years, we will randomize up to 8000 women undergoing scheduled/pre-labor CD
to either 500mg of intravenous azithromycin or identical placebo initiated prior to surgery. Both groups will also
receive standard single-dose cefazolin prophylaxis (or alternative in the 5% allergic to cephalosporin). Women
will be followed for 6 weeks according to adapted Centers for Disease Control and Prevention (CDC)
recommendations for ascertaining surgical site infections. The following specific aims will be addressed:
Primary Aim (Efficacy): Test in patients undergoing scheduled/prelabor CD if pre-incision adjunctive
azithromycin prophylaxis reduces the risk of post-CD infections compared to placebo. Primary Hypothesis:
Compared to standard prophylaxis (i.e. placebo + cefazolin alone), azithromycin (+ cefazolin) reduces the
incidence of post-CD infections (primary composite outcome of endometritis, wound and other severe infections).
Secondary Aim 1 (Safety): Assess the perinatal and maternal safety of pre-incision adjunctive azithromycin.
Hypothesis: Compared to standard prophylaxis (cefazolin alone), the use of azithromycin for scheduled CD does
not increase adverse perinatal outcomes including a perinatal composite of death, neonatal morbidities, cardiac
resuscitation, and hypertrophic pyloric stenosis. We will also examine maternal and neonatal adverse events.
Secondary Aim 2 (Resource use): Test the hypothesis that compared to standard cefazolin prophylaxis alone,
adjunctive azithromycin reduces a secondary maternal composite outcome (postpartum readmission or ER or
unscheduled clinic visits), maternal hospital stay, neonatal ICU admission and neonatal hospital stay.
We will collect and store biological specimens including maternal and umbilical cord blood for future
mechanistic and biomarker studies. We also plan a separate microbiome sub-study proposal.
Completion of this trial, ranked #1/28 by MFMU, will likely change policy, extending the benefits of
azithromycin prophylaxis to sch...

## Key facts

- **NIH application ID:** 10852501
- **Project number:** 1U01HD114634-01
- **Recipient organization:** GEORGE WASHINGTON UNIVERSITY
- **Principal Investigator:** Kim A Boggess
- **Activity code:** U01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2024
- **Award amount:** $3,614,140
- **Award type:** 1
- **Project period:** 2024-04-01 → 2029-03-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10852501

## Citation

> US National Institutes of Health, RePORTER application 10852501, Adjunctive Azithromycin Prophylaxis for Scheduled/Prelabor Cesarean Delivery (1U01HD114634-01). Retrieved via AI Analytics 2026-05-24 from https://api.ai-analytics.org/grant/nih/10852501. Licensed CC0.

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