Relationship of Amniotic Fluid Sludge and Short Cervix With a High Rate of Preterm Birth in Women After Cervical Cerclage

Abstract

Objective-We aims to determine the relationship of amniotic fluid sludge (AFS) and/or short cervical length (CL, ≤25 mm) with a high rate of preterm birth in women after cervical cerclage.Methods-A retrospective cohort study was conducted among singleton pregnancies after cervical cerclage between January 2018 and December 2021. A total of 296 patients who underwent transvaginal ultrasound to evaluate CL and the presence of AFS within 2 weeks after cerclage were included. Pregnancy outcome after cerclage was analyzed in accordance with the presence of AFS and CL ≤25 mm.Results-In patients with cerclage, AFS was an independent risk factor for preterm birth at <28 and <36 weeks but not for preterm birth at <32 weeks, and CL ≤25 mm was an independent risk factor for preterm birth at <28, <32, and <36 weeks. The Kaplan-Meier analysis showed that the association between the presence of AFS and short gestational age at delivery was statistically significant in women with CL ≤25 mm (log rank test, P = .000). The Cox regression analysis showed that these results remained significant after adjusting for confounding factors (P = .000). The negative linear relationships between AFS and CL (R = À0.454, P < .001) also explained the outcome.Conclusions-AFS and short cervix have a direct effect on pregnancies after cerclage. Mid-trimester AFS can become a supplementary ultrasound index for detecting preterm birth after cerclage in pregnant women with a short cervix.

Amniotic Sludge and Prematurity: Systematic Review and Meta-analysis

“…Another relevant aspect is that retrospective studies using ultrasound criteria, like all those herein evaluated, should be analyzed with caution, since they study a static image that may indicate a false diagnosis and skew the entire result. 22 Moreover, there is still no consensus on the diagnosis of sludge, which is often confused with vernix and meconium, especially when ultrasound is performed later during pregnancy. 22 Furthermore, the studies tend to publish only positive results, which may explain why each study evaluated a different outcome.…”

“…22 Moreover, there is still no consensus on the diagnosis of sludge, which is often confused with vernix and meconium, especially when ultrasound is performed later during pregnancy. 22 Furthermore, the studies tend to publish only positive results, which may explain why each study evaluated a different outcome. This may also explain the difficulty in finding outcomes that were evaluated by more than two or three authors, as well as elucidate why the current study has so many statistically significant results.…”

“…22 Moreover, there is still no consensus on the diagnosis of sludge, which is often confused with vernix and meconium, especially when ultrasound is performed later during pregnancy. 22…”