Effect of Antibiotic Treatment of Amniotic Fluid Sludge

A Review of the Literature: Amniotic Fluid "Sludge"-Clinical Significance and Perinatal Outcomes

Introduction: This paper seeks to report and emphasize the most important aspects from the scientific literature about the diagnostic accuracy of the amniotic fluid "sludge" (AFS), its characterization, its treatment, and its association with premature birth. AFS is defined as a floating freely hyperechogenic material within the amniotic cavity in the proximity of the internal os. Materials and Methods: We conducted a search on Pubmed and Google Scholar for relevant articles on the subject of amniotic fluid "sludge" published until January 2024. Searches were focused on articles about diagnosis, treatment, maternal and neonatal outcomes, risk of preterm birth, and case reports. The full-text reading stage resulted in the inclusion of 51 studies. Results: AFS is independently associated with chorioamnionitis, preterm delivery, short cervix, increased risk of neonatal morbidity, and cervical insufficiency. This hyperechogenic free-floating material is linked with preterm birth before 32 weeks of gestation, especially when it is associated with short cervical length. Discussion: Present studies identify some controversial benefits of antibiotics in reducing the incidence of preterm birth in women with AFS. Nevertheless, in this review, we can conclude that the presence of AFS in pregnancy is a marker for the microbial invasion of the amniotic cavity, as it is associated with preterm birth. Further studies on a larger group of patients are necessary to clarify and exactly define the terms of managing these cases.

Antibiotic therapy in patients with amniotic fluid sludge and risk of preterm birth: a meta-analysis

PURPOSE

Amniotic Fluid Sludge (AFS) has been theorized to be sonographic evidence of an underlying infection/inflammation and studies have concluded that approximately 10% of the patients who show signs of preterm labor with intact membranes have an underlying intraamniotic infection, mostly subclinical, carrying an increased risk for preterm birth with its subsequent neonatal and maternal complications. The purpose of the present systematic review is to evaluate the impact of antibiotic therapy on preterm birth rates of women diagnosed with AFS.

METHODS

We searched Medline, Scopus, the Cochrane Central Register of Controlled Trials CENTRAL, Google Scholar, and Clinicaltrials.gov databases for relevant articles published until the 30th of September 2022. Observational studies (prospective and retrospective) that evaluated the impact of antibiotics on preterm delivery rates of patients with AFS were considered eligible for inclusion. Statistical meta-analysis was performed with RStudio and we calculated pooled risk ratios (OR) and 95% confidence intervals (CI). To evaluate the information size, we performed trial sequential analysis (TSA) and the methodological quality of the included studies was assessed using RoBINS tools.

RESULTS

Overall, four retrospective cohort studies were included in the present systematic review and 369 women were enrolled. We demonstrated that preterm delivery prior to 34, 32 and 28 weeks of gestational age was comparable among the groups of women that had antibiotics and those that did not (OR: 0.34, 95% CI 0.05, 2.14, 0.40 [0.09, 1.66], 0.35 [0.08, 1.58], respectively) but the statistical heterogenicity of the studies included was high for every gestational period that was examined.

CONCLUSIONS

According to our study, we cannot conclude that the use of antibiotics in women with amniotic fluid sludge benefit the prognostic risk to deliver prematurely. It is quite clear that data from larger sample sizes and more well adjusted and designed studies are needed.

Prevention of spontaneous preterm delivery – an update on where we are today

Spontaneous preterm birth (delivery before 37 completed weeks) is the single most important cause of perinatal morbidity and mortality. The rate is increasing world-wide with a great disparity between low, middle and high income countries. It has been estimated that the cost of neonatal care for preterm babies is more than 4 times that of a term neonate admitted into the neonatal care. Furthermore, there are high costs associated with long-term morbidity in those who survive the neonatal period. Interventions to stop delivery once preterm labor starts are largely ineffective hence the best approach to reducing the rate and consequences is prevention. This is either primary (reducing or minimizing factors associated with preterm birth prior to and during pregnancy) or secondary - identification and amelioration (if possible) of factors in pregnancy that are associated with preterm labor. In the first category are optimizing maternal weight, promoting healthy nutrition, smoking cessation, birth spacing, avoidance of adolescent pregnancies and screening for and controlling various medical disorders as well as infections prior to pregnancy. Strategies in pregnancy, include early booking for prenatal care, screening and managing medical disorders and their complications, and identifying predisposing factors to preterm labor such as shortening of the cervix and timely instituting progesterone prophylaxis or cervical cerclage where appropriate. The use of biomarkers such as oncofetal fibronectin, placental alpha-macroglobulin-1 and IGFBP-1 where cervical screening is not available or to diagnosis PPROM would identify those that require close monitoring and allow the institution of antibiotics especially where infection is considered a predisposing factor. Irrespective of the approach to prevention, timing the administration of corticosteroids and where necessary tocolysis and magnesium sulfate are associated with an improved outcome. The role of genetics, infections and probiotics and how these emerging dimensions help in the diagnosis of preterm birth and consequently prevention are exciting and hopefully may identify sub-populations for targeted strategies.

Amniotic Sludge and Prematurity: Systematic Review and Meta-analysis

OBJECTIVE

 To perform a systematic review and meta-analysis of studies on maternal, fetal, and neonatal outcomes of women with singleton pregnancies, after spontaneous conception, and with the diagnosis of amniotic sludge before 37 weeks of gestational age.

DATA SOURCES

 We conducted a search on the PubMed, Cochrane, Bireme, and Theses databases until June 2022.

SELECTION OF STUDIES

 Using the keywords intra-amniotic sludge or fluid sludge or echogenic particles, we found 263 articles, 132 of which were duplicates, and 70 were discarded because they did not meet the inclusion criteria.

DATA COLLECTION

 The articles retrieved were analyzed by 2 reviewers; 61 were selected for full-text analysis, 18 were included for a qualitative analysis, and 14, for a quantitative analysis.

DATA SYNTHESIS

 Among the maternal outcomes analyzed, there was an increased risk of preterm labor (95% confidence interval [95%CI]: 1.45-2.03), premature rupture of ovular membranes (95%CI: 1.99-3.79), and clinical (95%CI: 1.41-6.19) and histological chorioamnionitis (95%CI: 1.75-3.12). Regarding the fetal outcomes, there was a significant increase in the risk of morbidity (95%CI: 1.80-3.17), mortality (95%CI: 1.14-18.57), admission to the Neonatal Intensive Care Unit (NICU; 95%CI: 1.17-1.95), and neonatal sepsis (95%CI: 2.29-7.55).

CONCLUSION

 The results of the present study indicate that the presence of amniotic sludge is a risk marker for preterm delivery. Despite the heterogeneity of the studies analyzed, even in patients with other risk factors for prematurity, such as short cervix and previous preterm delivery, the presence of amniotic sludge increases the risk of premature labor. Moreover, antibiotic therapy seems to be a treatment for amniotic sludge, and it may prolong pregnancy.

Antenatal azithromycin to prevent preterm birth in pregnant women with vaginal cerclage: A randomized clinical trial

Objective

To assess whether antenatal azithromycin given to pregnant women with vaginal cerclage can reduce preterm birth or not.

Materials and Methods

We randomized 50 pregnant ladies who underwent cerclage at Ain Shams University Maternity Hospital in group A (receiving 500 mg Azithromycin oral tablets (Zithrokan^®, Hikma, Egypt) one tablet orally twice daily for three days in 3 courses at 14^th, 24^th and 32^nd week, plus usual antenatal care) and an identical group B (receiving usual antenatal care). Our primary outcome was gestational age at delivery, and secondary outcomes were birthweight, mode of delivery, and maternal, and perinatal complications. This study was registered on ClinicalTrials.gov with number: NCT04278937.

Results

Pregnancy was more prolonged in the Azithromycin group (delivery at 36.8 weeks vs 34.1 weeks; p=0.017). Also, a higher birthweight was observed in the Azithromycin group (2932.6 gm vs 2401.8 gm; p=0.006). No significant difference was found between the two groups as regards to other outcomes (miscarriage, stillbirth, neonatal intensive care unit admission, antepartum hemorrhage, postpartum pyrexia, need for blood transfusion).

Conclusion

Adding antenatal azithromycin to women undergoing cerclage prolongs pregnancy and reduces the risk of preterm birth, with a slight increase in birthweight.

Prognosis and Prognostic Factors of Patients with Emergent Cerclage: A Japanese Single-Center Study

Objectives

The aims of this study were to clarify the following: (1) how often does prolonged pregnancy ≥34 weeks occur in patients with emergent cerclage without progesterone and (2) the risk factors preventing such pregnancy continuation.

Materials and Methods

This retrospective observational study was performed using medical records of patients for whom emergent cerclage had been performed between April 2006 and December 2018 in our institute.

Results

Emergent cerclage was performed in 123 patients (median age: 34, interquartile range: 31–36). Primiparous patients numbered 44 (36%). A history of spontaneous preterm birth (SPTB) was present in 30 (24%). The median presurgical cervical length (CL) was 16 (8–21) mm at surgery. Of the 123, 20 (16%) were delivered at 33 + 6 weeks or less (<34 weeks). We conducted logistic regression analysis of the risk factors of SPTBs <34 weeks after cerclage. Three risk factors were identified that increased the risk of SPTB <34 weeks: presurgical CL 0 mm (odds ratio (OR): 5.30; 95% confidence interval (CI): 1.58–17.7), a history of SPTB (OR: 4.65; 95% CI: 1.38–15.7), and the presence of sludge (OR: 4.14; 95% CI: 1.20–14.3).

Conclusion

Three risk factors predicted SPTB <34 weeks after emergency cerclage without progesterone administration: unmeasurable CL (CL 0 mm), a history of SPTB, and the presence of sludge on ultrasound. SPTB <34 weeks occurred after emergency cerclage in 16% of patients, being comparable with the recent data with progesterone.

Does amniotic fluid sludge result in preterm labor in pregnancies after assisted reproduction technology? A nested Case - Control study

OBJECTIVE

to investigate the relationship between the Amniotic fluid Sludge exposure during pregnancy and the Preterm Labor (PTL) in pregnant women who had undergone Assisted Reproductive Technology procedures (ART) in Royan institute.

MATERIALS AND METHODS

It was a nested case-control study that was conducted on 110 eligible pregnant women who had undergone IVF procedure in Royan institute, Tehran, Iran. The final sample size was 63 subjects with Amniotic fluid Sludge and 67 subjects with normal Amniotic fluid. Delivery before 37 of gestation was considered as PTL.The study was approved by the ethics committee of the Royan institute and the written consent form was filled by participants. Data was entered to the SPSS (version 21, SPSS, Inc.). The baseline characteristics of the participants were described as absolute (n) and relative (%) frequencies for the covariates. Man Whitney and T-Test were used to compare the mean of covariates and the P-value lower than 0.05 was considered significant. The prevalence of the PTL was compared between two groups.

RESULTS

The mean Gestational Age at delivery in case and control group were 36.46 ± 3.45 and 38.03 ± 1.61, respectively which was significant (p = .01). The prevalence of PTL in case and control group were 23.8% and 10.4% respectively which was significant (p = .04). The percentage of cases with cervical length less than 30 (mm) in case and control group were 28.6% and 10.4%, respectively (p = .008) and the percentage of cerclage in case and control group were 33.3% and 7.5% respectively, (p = .00) which were significant statistically.

CONCLUSION

The amniotic fluid sludge has a direct effect on the cervical length of pregnancies after ART. In such cases, PTB will be probable in the presence of sludge in spite of preventive treatments such as cerclage.