Indomethacin and Cefazolin for physical exam-indicated cerclage to improve latency - a protocol validation study.

Abstract

Objective: A single center randomized trial showed improved latency with use of indomethacin and cefazolin (I/C) during and following exam-indicated cerclage (EIC). The same center recently published a pre/post comparison demonstrating similar results. This research aimed to validate the protocol in a different setting.

Study design: Retrospective cohort study of singleton pregnancies undergoing EIC at a single center between 2013 and 2022. EIC was performed for painless cervical dilation between 16-23 weeks gestation with dilation ≥1cm. Exposure was defined as receipt of I/C during and following EIC. The primary outcome was latency ≥28 days after cerclage placement. Secondary outcomes included latency; gestational age at delivery; delivery ≤28 weeks; preterm prelabor rupture of membranes (PPROM); intraamniotic infection (IAI); and median birth weight. Bivariate statistics were used to analyze data; multivariable regression analyses were used to control for confounders (progesterone use, cervical dilation at time of cerclage placement, history of PTB, and prolapsing membranes).

Results: EIC was placed in 81 pregnancies, and 48 (59%) received I/C. Baseline characteristics did not differ between groups, except that prolapsing membranes were significantly less likely in patients receiving I/C (6.2% vs. 21.2%; p=0.04). Latency ≥28 days occurred in 90% of I/C recipients and 82% of the controls (p=0.32); this difference remained non-significant after controlling for confounders (adjusted relative risk: 1.02 [95% confidence interval: 0.85, 1.21]). I/C recipients had lower rates of IAI (4.2 vs. 24.2%, p=0.007), even after adjustment (adjusted relative risk: 0.18 [95% confidence interval: 0.04, 0.74]). Other secondary outcomes did not differ.

Conclusion: Use of indomethacin/cefazolin at the time of exam-indicated cerclage at this center was not associated with increased latency to delivery (albeit in a small cohort) but was associated with lower rates of intraamniotic infection. Larger-scale validation studies would be helpful to confirm the value of this intervention.