Cervical length and quantitative fetal fibronectin in the prediction of spontaneous preterm birth in asymptomatic women with congenital uterine anomaly

How to screen the cervix and reduce the risk of spontaneous preterm birth in asymptomatic women without a prior preterm birth

Preterm birth (PTB) is a leading cause of perinatal morbidity and mortality globally. PTB rates have increased in South Korea despite reduction in birth rates. A history of PTB is a strong predictor of subsequent PTB and screening of cervical length between 16 0/7 weeks and 24 0/7 weeks of gestation is recommended in women with a singleton pregnancy and a prior spontaneous PTB. However, the prediction and prevention of spontaneous PTBs in women without a prior PTB remain a matter of debate. The scope of this review article comprises cervical screening and prevention strategies for PTB in asymptomatic women without a prior PTB, based on recent evidence and guidelines.

Undiagnosed uterine anomalies revealed by breech on ultrasound prior to external cephalic version - A chance to take a closer look

OBJECTIVE

Uterine anomalies (UA) occur in up to 6.7% of women. Breech is eight times more likely to occur with UA which may not be diagnosed prior to pregnancy and may only be found in the third trimester with breech. The objective of the study is to assess the prevalence of both already known and newly sonographically diagnosed UA in breech from 36 weeks of gestation and its impact on external cephalic version (ECV), delivery options and perinatal outcomes.

STUDY DESIGN

We recruited 469 women with breech at 36 weeks of gestation over a 2-year period at the Charité University Hospital, Berlin. Ultrasound examination was performed to rule out UA. Patients with known and newly 'de novo' diagnosed anomalies were identified and delivery options and perinatal outcomes analyzed.

RESULTS

The 'de novo' diagnosis of UA at 36-37 weeks of pregnancy with breech was found to be significantly higher compared to the diagnosis prior to pregnancy with 4.5% vs 1.5% (p < 0.001 and odds ratio 4 with 95% confidence interval 2.12-7.69). Anomalies found included 53.6% bicornis unicollis, 39.3% subseptus, 3.6% unicornis and 3.6% didelphys. A trial of vaginal breech delivery was successful in 55.5% of cases when attempted. There were no successful ECVs.

CONCLUSION

Breech is a marker for uterine malformation. Diagnosis of UA with breech can be up to four times improved with focused ultrasound screening in pregnancy even from 36 weeks of gestation prior to ECV to identify missed anomalies. Timely diagnosis aids antenatal care and delivery planning. Importantly, definitive diagnosis and treatment can be planned postpartum to improve outcomes in future pregnancies. ECV plays a limited role in selected cases.

The Potential Mechanism of Zishen Yutai Pills against Threatened Abortion: An Approach Involving Network Pharmacology and Experimental Evidence

Threatened abortion (TA) is the most common complication in early pregnancy and is caused by anxiety and depressive symptoms. The Zishen Yutai Pill (ZYP) is a traditional herbal formula that is commonly used to treat TA. However, the pharmacological mechanisms underlying the effect of ZYP have yet to be elucidated. To disclose the mechanism of ZYP in the treatment of TA, first, we identified the chemical constituents of ZYP from multiple databases and then predicted the potential targets of TA by applying the GeneCards database. A protein-protein interaction (PPI) network was then constructed to allow the screening of hub targets. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGGs) enrichment analyses were also performed and the Database for Annotation Visualization and Integrated Discovery server was used to identify critical biological processes and signaling pathways. Cytoscape software was used to construct a Compound-Target-Pathway. Furthermore, we analyzed ZYP by UPLC-Q-TOF/MS, then the RU486-induced TA rat model was established, and the reliability of the network pharmacology prediction results was verified. Finally, the mechanisms responsible for the action of ZYP on TA were revealed by qRT-PCR and molecular docking. Database screening identified a total of 161 active compounds in ZYP and 324 TA-related targets. And, we identified 42 compounds from ZYP by UPLC-Q-TOF/MS. Inflammation and apoptosis were identified as the main biological processes. GO and KEGG analyses identified that the MAPK and PI3K/Akt pathways were the key functional pathways that respond to ZYP. The results showed that ZYP treatment significantly increased maternal weight, significantly increased the levels of estradiol and progesterone, and attenuated histopathological changes in a rat model of TA. Data indicated that ZYP treatment improved pregnancy outcomes in the rat model of TA. QRT-PCR data showed that ZYP reduced inflammation and apoptosis by regulating the MAPK and PI3K/Akt pathways. In addition, molecule docking results identified a range of key compounds, including Pik3a, Mapk14, Mapk1, Mapk3, Mapk8 Tnf, Il6, and Cas8. In summary, we performed network pharmacological analysis and experimental validation and identified that ZYP exerts an effect on TA by regulating the MAPK and PI3K/Akt pathways and by inhibiting the expression levels of proinflammatory cytokines and genes related to apoptosis.

Preterm labor with intact membranes: a simple noninvasive method to identify patients at risk for intra-amniotic infection and/or inflammation

OBJECTIVE

To develop a noninvasive scoring system to identify patients at high risk for intra-amniotic infection and/or inflammation, which would reduce the need for amniocentesis.

METHODS

This prospective cohort study comprised patients admitted with preterm labor and intact membranes (20-34 weeks of gestation) who underwent a transabdominal amniocentesis and for whom concentrations of quantitative cervical fetal fibronectin and of maternal serum C-reactive protein (CRP) were determined. Intra-amniotic infection was defined as a positive amniotic fluid culture for microorganisms. Intra-amniotic inflammation was defined as an amniotic fluid matrix metalloproteinase-8 concentration >23 ng/mL. Multivariate logistic regression analysis was performed to identify intra-amniotic infection/inflammtion with noninvasive parameters that had a significant relationship with univariate analysis. With four parameters identified by multivariate analysis, we generated a noninvasive risk scoring system.

RESULTS

Of the study population consisting of 138 singleton pregnant women, (1) the overall rate of intra-amniotic infection/inflammation was 28.3% (39/138); (2) four parameters were used to develop a noninvasive risk scoring system [i.e. cervical fetal fibronectin concentration (score 0-2), maternal serum CRP concentration (score 0-2), cervical dilatation (score 0-2), and gestational age at presentation (score 0-1)]; the total score ranges from 0 to 7; 3) the area under the curve of the risk score was 0.96 (95% confidence interval (CI), 0.92-0.99), significantly higher than that of each predictor in the identification of intra-amniotic infection/inflammation (p < .001, for all); 4) the risk score with a cutoff of 4 had a sensitivity of 94.9% (37/39), a specificity of 90.9% (90/99), a positive predictive value of 80.4% (37/46), a negative predictive value of 97.8% (90/92), a positive likelihood ratio of 10.4 (95% CI, 5.6-19.5), and a negative likelihood ratio of 0.06 (95% CI, 0.15-0.22) in the identification of intra-amniotic infection/inflammation.

CONCLUSIONS

(1) The combination of four parameters (concentrations of cervical fetal fibronectin and maternal serum CRP, cervical dilatation, and gestational age) was independently associated with intra-amniotic infection and/or inflammation; and (2) the risk scoring system comprised of the combination of 4 noninvasive parameters was sensitive and specific to identify the patients at risk for intra-amniotic infection and/or inflammation.

Obstetric Complications in Women With Congenital Uterine Anomalies According to the 2013 European Society of Human Reproduction and Embryology and the European Society for Gynaecological Endoscopy Classification: A Systematic Review and Meta-analysis

OBJECTIVE

To assess the risk for obstetric complications in women with congenital uterine anomalies and the risk in each main class of uterine anomaly (U2 [septate], U3 [bicorporeal], U4 [hemi-uterus]), based on the 2013 classification by the ESHRE (European Society of Human Reproduction and Embryology) and the ESGE (European Society for Gynaecological Endoscopy).

DATA SOURCES

MEDLINE, Scopus, and ClinicalTrials.gov were searched from inception until January 2021. The reference list of all included articles and previous systematic reviews were also screened to identify potential additional articles.

METHODS OF STUDY SELECTION

Comparative and noncomparative studies that investigated the obstetric outcomes of women with any type of known congenital uterine anomaly were considered eligible for inclusion. Screening and eligibility assessment was performed independently by two reviewers.

TABULATION, INTEGRATION, AND RESULTS

Forty-seven studies were included. The quality of included comparative studies was assessed using the Newcastle-Ottawa Quality Assessment Scale. Odds ratios (ORs), pooled proportions of each obstetric outcome, and 95% CIs were calculated in RevMan and Stata accordingly, using random effects models. Congenital uterine anomalies were associated with increased risk of preterm birth (OR 3.89, 95% CI 3.11-4.88); cervical insufficiency (OR 15.13, 95% CI 11.74-19.50); prelabor rupture of membranes (OR 2.48, 95% CI 1.38-4.48); fetal malpresentation (OR 11.11, 95% CI 5.74-21.49); fetal growth restriction (OR 3.75, 95% CI 1.88-7.46); placental abruption (OR 5.21, 95% CI 3.34-8.13); placenta previa (OR 4.00, 95% CI 1.87-8.56); placental retention (OR 1.71, 95% CI 1.16-2.52); and cesarean birth (OR 4.52, 95% CI 2.19-9.31); when compared with those without anomalies. Pooled estimated risks were 25% for preterm birth, 40% for fetal malpresentation, 64% for cesarean birth, 12% for prelabor rupture of membranes, 15% for fetal growth restriction, 4% for placental abruption, 5% for preeclampsia, 13% for cervical insufficiency, and 2% for placenta previa. Classes U2 (septate), U3 (bicorporeal), and U4 (hemi-uterus) were also associated independently with preterm birth, fetal malpresentation, cesarean birth, and placental abruption.

CONCLUSION

Congenital uterine anomalies are associated with obstetric complications across all examined ESHRE and ESGE classifications.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO, CRD42021244487.

Cervical Assessment for Predicting Preterm Birth-Cervical Length and Beyond

Preterm birth is considered one of the main etiologies of neonatal death, as well as short- and long-term disability worldwide. A number of pathophysiological processes take place in the final unifying factor of cervical modifications that leads to preterm birth. In women at high risk for preterm birth, cervical assessment is commonly used for prediction and further risk stratification. This review outlines the rationale for cervical length screening for preterm birth prediction in different clinical settings within existing and evolving new technologies to assess cervical remodeling.

Rapid quality improvement in a preterm birth clinic care pathway during the COVID-19 pandemic

Background

Preterm birth (PTB) occurs in 8% of births in the UK. At Imperial College Healthcare NHS Trust, our PTB prevention clinic manages the care of approximately 1000 women/year. Women referred to the clinic are seen from 12 weeks of pregnancy with subsequent appointments every 2–4 weeks to measure cervical length (CL) using transvaginal ultrasound (TVUS). Women with a history of cervical weakness or short cervix on TVUS are offered a cervical cerclage.

Local problem

During the COVID-19 outbreak, pregnant women were strongly advised to avoid social mixing and public transport. The National Health Service had to rapidly adopt remote consultation and redesign clinical pathways in order to reduce transmission, exposure and spread among women at high risk of PTB.

Methods

We focused on Specific, Measurable, Achievable, Realistic and Timebound aims and used a driver diagram to visualise our changes. We used a series of Plan Do Study Act cycles to evaluate and adapt change ideas through the UK’s national lockdown during the COVID-19 pandemic between 23 March and 29 May 2020.

Results

We reduced the number of face-to-face appointments by 54%. This was achieved by increasing remote telephone consultations from 0% to 64%, and by reducing the intensity of surveillance. The rate of regional anaesthetic was increased from 53% to 95% for cerclage placement in order to minimise the number of aerosol-generating procedures. Patient and staff satisfaction responses to these changes were used to tailor practices. No women tested positive for COVID-19 during the study period.

Conclusions

By using quality improvement methodology, we were able to safely and rapidly implement a new care pathway for women at high risk of PTB which was acceptable to patients and staff, and effective in reducing exposure of COVID-19.

Cervical length surveillance for predicting spontaneous preterm birth in women with uterine anomalies: A cohort study

INTRODUCTION

Uterine anomalies occur in an estimated 5% of women and have been shown to confer a higher risk of spontaneous preterm birth (SPTB). A sonographically short cervix (<25 mm) is a risk indicator for SPTB, although its predictive utility has been little studied in this specific high-risk population. We aimed to assess the pregnancy outcomes and predictive ability of short cervix in a cohort of women with uterine anomalies attending a high-risk antenatal clinic.

MATERIAL AND METHODS

This historical cohort study assessed all pregnancies in women with congenital uterine anomalies referred to the Preterm labor Clinic at the Royal Women's Hospital, Melbourne, Australia, between 2004 and 2013. Logistic and linear regressions and receiver-operator curves were used to examine associations between cervical length and preterm birth.

RESULTS

SPTB (<37 weeks' gestation) occurred in 23% of the 86 pregnancies (n = 20); rates by subgroup were: unicornuate uterus 60% (n = 3/5), uterus didelphys 40% (n = 6/15), bicornuate uterus 18% (n = 9/51), septate uterus 13% (n = 2/15). Preterm prelabor rupture of membranes occurred in 55% of spontaneous preterm births and was not independently associated with the presence of cervical cerclage or ureaplasma urealyticum. Short cervical length was associated with SPTB in women with septate uterus. Short cervix at 24 weeks (not at 16 or 20 weeks) was moderately predictive of SPTB < 34 weeks.

CONCLUSIONS

Women with uterine anomalies are at increased risk of spontaneous preterm birth, particularly those with unicornuate uterus or uterus didelphys, but cervical surveillance did not identify these cases. Short cervix may be associated with SPTB in women with septate uterus. Preterm prelabor rupture of membranes occurred in 55% of SPTB. More research is required into etiology to help determine appropriate monitoring and treatment.

Preterm birth prediction in asymptomatic women at mid-gestation using a panel of novel protein biomarkers: the Prediction of PreTerm Labor (PPeTaL) study

BACKGROUND

Accurate prediction of spontaneous preterm labor/preterm birth in asymptomatic women remains an elusive clinical challenge because of the multi-etiological nature of preterm birth.

OBJECTIVE

The aim of this study was to develop and validate an immunoassay-based, multi-biomarker test to predict spontaneous preterm birth.

MATERIALS AND METHODS

This was an observational cohort study of women delivering from December 2017 to February 2019 at 2 maternity hospitals in Melbourne, Australia. Cervicovaginal fluid samples were collected from asymptomatic women at gestational week 16⁺⁰-24⁺⁰, and biomarker concentrations were quantified by enzyme-linked immunosorbent assay. Women were assigned to a training cohort (n = 136) and a validation cohort (n = 150) based on chronological delivery dates.

RESULTS

Seven candidate biomarkers representing key pathways in utero-cervical remodeling were discovered by high-throughput bioinformatic search, and their significance in both in vivo and in vitro studies was assessed. Using a combination of the biomarkers for the first 136 women allocated to the training cohort, we developed an algorithm to stratify term birth (n = 124) and spontaneous preterm birth (n = 12) samples with a sensitivity of 100% (95% confidence interval, 76-100%) and a specificity of 74% (95% confidence interval, 66-81%). The algorithm was further validated in a subsequent cohort of 150 women (n = 139 term birth and n = 11 preterm birth), achieving a sensitivity of 91% (95% confidence interval, 62-100%) and a specificity of 78% (95% confidence interval, 70-84%).

CONCLUSION

We have identified a panel of biomarkers that yield clinically useful diagnostic values when combined in a multiplex algorithm. The early identification of asymptomatic women at risk for preterm birth would allow women to be triaged to specialist clinics for further assessment and appropriate preventive treatment.