Utility of ultrasound assessment in management of pregnancies with preterm prelabor rupture of membranes

Value of fetal echocardiographic examination in pregnancies complicated by preterm premature rupture of membranes

OBJECTIVES

Cardiopulmonary and infectious complications are more common in preterm newborns after preterm premature rupture of membranes (pPROM). Fetal echocardiography may be helpful in predicting neonatal condition. Our aim was to assess the cardiovascular changes in fetuses from pregnancies complicated by pPROM and possible utility in predicting the intrauterine or neonatal infection, and neonatal heart failure (HF).

METHODS

It was a prospective study enrolling 46 women with singleton pregnancies complicated by pPROM between 18+0 and 33+6 weeks of gestation and followed until delivery. 46 women with uncomplicated pregnancies served as a control group. Fetal echocardiographic examinations with the assessment of cardiac structure and function (including pulmonary circulation) were performed in all patients.

RESULTS

Mean gestational age of pPROM patients was 26 weeks. Parameters suggesting impaired cardiac function in fetuses from pPROM were: higher right ventricle Tei index (0.48 vs. 0.42 p<0.001), lower blood flow velocity in Ao z-score (0.14 vs. 0.84 p=0.005), lower cardiovascular profile score (CVPS), higher rate of tricuspid regurgitation (18.2 % vs. 4.4 % p=0.04) and pericardial effusion (32.6 vs. 0 %). Intrauterine infection was diagnosed in 18 patients (39 %). 4 (8.7 %) newborns met the criteria of early onset sepsis (EOS). HF was diagnosed in 9 newborns. In fetal echocardiographic examination HF group had shorter mitral valve inflow time and higher left ventricle Tei index (0.58 vs. 0.49 p=0.007).

CONCLUSIONS

Worse cardiac function was observed in fetuses from pPROM compared to fetuses from uncomplicated pregnancies.

Association Analysis Between Maternal Neutrophil Ratio and the Risk of Histological Chorioamnionitis in Pregnant Women with Premature Rupture of Membranes in Late Pregnancy

Background

We aimed to investigate the association between maternal neutrophil ratio and histological chorioamnionitis (HCA) risk in pregnant women with premature rupture of membranes (PROM) in late pregnancy.

Methods

A retrospective analysis was conducted on 95 cases of women with PROM in their late pregnancy between March 2018 and August 2021. These women were divided into two groups based on the presence of HCA. General clinical data and laboratory indicators were compared between the two groups. A generalized additive model was used for curve fitting, and a segmented regression model was used to explain further the non-linear relationship between neutrophil ratio and HCA risk.

Results

After adjusting for confounding factors, the curve fitting showed a "U"-shaped curve relationship between the neutrophil ratio and the risk of HCA. When the neutrophil ratio was <76.3%, the risk of HCA exhibited a decreasing trend, but the difference was not statistically significant (adjusted OR = 0.884, 95% CI: 0.781-1.001, P = 0.053). However, when the neutrophil ratio was >76.3%, the HCA risk was significantly increased (adjusted OR = 1.339, 95% CI: 1.067-1.680, P = 0.012). Furthermore, we equally divided the neutrophil ratio into three groups. The risk of HCA was significantly increased in the low-ratio group (OR = 4.292, 95% CI: 1.247-14.706, P = 0.021) compared with the middle-ratio group, which was used as the reference group. Similarly, the HCA risk of the high-ratio group (OR = 13.145, 95% CI: 1.796-96.233, P = 0.011) was also significantly enhanced. However, there was no significant difference in HCA risk between the high-ratio and low-ratio groups (OR = 1.182, 95% CI: 0.357-3.909, P = 0.784).

Conclusion

There was a significant "U"-shaped relationship between maternal neutrophil ratio and HCA risk in women with PROM in late pregnancy.

Development and Validation of a Multivariable Predictive Model for the Risk of Histologic Chorioamnionitis in Patients with Premature Rupture of Membranes in the Late Preterm and Term

Background

This study aimed to develop and validate a model to predict histologic chorioamnionitis (HCA) risk in late preterm and term premature rupture of membranes (PROM) patients using clinical and laboratory parameters.

Methods

We conducted a retrospective study on 116 late preterm and term PROM cases, divided into a training (n=81) and a validation set (n=35). A multivariable logistic regression model was developed using the training set. Performance was assessed via the area under the receiver operating characteristic curve (AUC) and net reclassification index (NRI). Decision curve analysis (DCA) evaluated the model's clinical utility. Additionally, nomograms and a web version of the model were developed.

Results

In the training set, the combined model constructed using maternal BMI, gravidity, amniotic fluid characteristics, and prenatal white blood cell (WBC) count showed significantly higher AUC than WBC alone (0.859 vs 0.710, P=0.010), with improved accuracy and sensitivity. In the validation set, the AUC of the combined model remained higher than that of WBC, but the difference was not statistically significant (0.728 vs 0.584, P=0.173). NRI analysis indicated that the combined model improved the correct classification of HCA by 25.0% (P=0.012) compared to that of WBC alone. DCA demonstrated that the combined model had a higher net benefit than WBC in most cases. The nomograms and web version of the model provided convenient tools for clinicians to predict the risk of HCA.

Conclusion

This study successfully developed and validated a clinically feasible multivariable model to predict the risk of HCA in women with late preterm and term PROM.

Chorioamnionitis: An Update on Diagnostic Evaluation

Chorioamnionitis remains a major cause of preterm birth and maternal and neonatal morbidity. We reviewed the current evidence for the diagnostic tests of chorioamnionitis and how this relates to clinical practice today. A comprehensive literature search and review was conducted on chorioamnionitis and intra-uterine inflammation. Data from randomized control trials and systematic reviews were prioritized. This review highlights that sterile inflammation plays an important role in chorioamnionitis and that the current tests for chorioamnionitis including clinical criteria, maternal plasma and vaginal biomarkers lack diagnostic accuracy. Concerningly, these tests often rely on detecting an inflammatory response after damage has occurred to the fetus. Care should be taken when interpreting current investigations for the diagnosis of chorioamnionitis and how they guide obstetric/neonatal management. There is an urgent need for further validation of current diagnostic tests and the development of novel, accurate, minimally invasive tests that detect subclinical intra-uterine inflammation.

Using Middle Cerebral Artery Doppler Ultrasound to Predict Clinical Chorioamnionitis After Preterm Prelabor Rupture of Membranes

BACKGROUND

In neonates, blood flow to the brain as measured by peak systolic velocity (PSV) in the middle cerebral artery (MCA) is altered in pregnancies affected by chorioamnionitis.

OBJECTIVE

We aim to determine whether PSV and other measures of flow in the MCA in the fetus are altered prior to the development of clinical chorioamnionitis following preterm prelabor rupture of membranes (PPROM).

METHODS

 This was a prospective observational study. Fifty patients from one institution were recruited after being diagnosed with PPROM between 23 weeks zero days and 33 weeks six days gestation. We performed measurements of the PSV in the fetal MCA on a weekly basis following PPROM and used the value taken closest to the time of delivery for our statistical analysis. The primary outcome assessed was clinical chorioamnionitis, and the exposure of interest was MCA PSV. Additional independent variables of interest were other Doppler measures of the MCA. Secondary outcomes included histological chorioamnionitis and other measures of neonatal health, including sepsis, days in the neonatal intensive care unit (NICU), and death.

RESULTS

Of the 50 patients recruited to our study, eight (16%) developed clinical chorioamnionitis, similar to previously reported values in the general population. The PSV in the MCA was not significantly associated with the development of clinical chorioamnionitis. However, an elevated MCA pulsatility index (PI), a measure of resistance to flow, was associated with a higher probability of developing clinical chorioamnionitis.

CONCLUSION

 There does not appear to be a difference in the PSV of the MCA of fetuses in pregnancies following PPROM with impending chorioamnionitis. However, elevated PI in the MCA could be a marker of impending chorioamnionitis in PPROM. Larger studies are needed to confirm these findings.

Non-invasive prediction of histologic chorioamnionitis using maternal serum markers in women with preterm prelabour rupture of membranes

PROBLEM

This study aimed to evaluate and compare the predictive accuracy of serum markers for histological chorioamnionitis (HCA) among women with preterm prelabour rupture of membranes (PPROM), and to develop a nomogram prediction model to minimize the damage of the disease.

METHOD OF STUDY

This case-control study included 153 pregnant women with PPROM with a gestational age of 20⁺⁰ ∼ 36⁺⁶ weeks. The subjects were assigned into two groups: PPROM with and without HCA. According to the results of Logistic regression analysis, the predictive equation and nomogram were generated using key parameters, and the discrimination and consistency of the model were evaluated by receiver operating characteristic (ROC) curves and calibration curves.

RESULTS

From 153 subjects with PPROM, 77 developed HCA. Compared with the PPROM without HCA group, the CRP, PCT and NLR were significantly higher in HCA group (P<0.001), and the CRP had the highest predictive value. The area under the curve (AUC) of the prediction model was 0.873, and the sensitivity and specificity of predicting HCA were 68.8% and 92.1%, respectively. And the calibration curves fitted well with the realistic situation.

CONCLUSION

Maternal serum CRP and NLR could be used as predictive biomarkers for HCA in women with PPROM, while PCT needs to be further explored due to its slightly lower predictive value. Our serum markers and gestational age at PPROM could be used as a non-invasive and convenient method to predict HCA in women with PPROM. This article is protected by copyright. All rights reserved.

Hemodynamic assessment in patients with preterm premature rupture of the membranes (pPROM)

OBJECTIVE

The aim of this study was to assess the hemodynamic differences in women with pPROM versus physiological pregnancies.

STUDY DESIGN

This was a prospective case control study of 15 patients with pPROM and 45 controls. Patients and controls were submitted at enrollment to a non-invasive hemodynamic evaluation with UltraSonic Cardiac Output Monitor (USCOM), and to blood tests to check white blood cells count and C-reactive protein (CRP) levels. We followed pPROM patients until delivery noting fetal/neonatal and maternal unfavorable outcomes (maternal fever, APGAR 1' and 5'< 7, stillbirth).

RESULTS

Patients with pPROM showed higher values of cardiac output (9.1 ± 2.3 vs 7.1 ± 0.85, p < 0.01), lower systemic vascular resistances (792.1 ± 162 vs 1006.2 ± 110.7, p < 0.01), higher minute distance (32.3 ± 7.8 vs 25 ± 2.8, p < 0.01), lower Potential to Kinetic Energy Ratio (16.5 ± 5.3 vs 22.4 ± 6.8, p < 0.01), higher heart rate (97.5 ± 15.4 vs 82.4 ± 12, p < 0.01) and higher oxygen delivery (1313.2 ± 325.8 vs 1080.7 ± 151.8, p < 0.01) vs. controls. Six out of 15 pPROM patients had an unfavorable outcome. There were no significant differences in CRP levels and WBC count at admission in the two pPROM subgroups, whereas maternal hemodynamics was characterized by lower SVR (718 ± 72 vs 863 ± 123, p = 0.02) in subsequently complicated patients.

CONCLUSIONS

Maternal hemodynamics is altered in pPROM patients, with a lower Systemic Vascular Resistance and higher Cardiac Output vs. controls. This hyperdynamic circulation appears to anticipates the changes of serum markers of inflammation (CRP, WBC count) and seems to be more pronounced at admission in pPROM patients developing unfavorable outcomes.

Chorioamnionitis and Risk for Maternal and Neonatal Sepsis: A Systematic Review and Meta-analysis

OBJECTIVE

To estimate the risk of maternal and neonatal sepsis associated with chorioamnionitis.

DATA SOURCES

PubMed, BIOSIS, and ClinicalTrials.gov databases were systematically searched for full-text articles in English from inception until May 11, 2020.

METHODS OF STUDY SELECTION

We screened 1,251 studies. Randomized controlled trials, case-control, or cohort studies quantifying a relationship between chorioamnionitis and sepsis in mothers (postpartum) or neonates born at greater than 22 weeks of gestation were eligible. Studies were grouped for meta-analyses according to exposures of histologic or clinical chorioamnionitis and outcomes of maternal or neonatal sepsis.

TABULATION, INTEGRATION, AND RESULTS

One hundred three studies were included, and 55 met criteria for meta-analysis (39 studies of preterm neonates, 10 studies of general populations of preterm and term neonates, and six studies of late preterm and term neonates). Study details and quantitative data were abstracted. Random-effects models were used to generate pooled odds ratios (ORs); most studies only reported unadjusted results. Histologic chorioamnionitis was associated with confirmed and any early-onset neonatal sepsis (unadjusted pooled ORs 4.42 [95% CI 2.68-7.29] and 5.88 [95% CI 3.68-9.41], respectively). Clinical chorioamnionitis was also associated with confirmed and any early-onset neonatal sepsis (unadjusted pooled ORs 6.82 [95% CI 4.93-9.45] and 3.90 [95% CI 2.74-5.55], respectively). Additionally, histologic and clinical chorioamnionitis were each associated with higher odds of late-onset sepsis in preterm neonates. Confirmed sepsis incidence was 7% (early-onset) and 22% (late-onset) for histologic and 6% (early-onset) and 26% (late-onset) for clinical chorioamnionitis-exposed neonates. Three studies evaluated chorioamnionitis and maternal sepsis and were inconclusive.

CONCLUSION

Both histologic and clinical chorioamnionitis were associated with early- and late-onset sepsis in neonates. Overall, our findings support current guidelines for preventative neonatal care. There was insufficient evidence to determine the association between chorioamnionitis and maternal sepsis.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO, CRD42020156812.

Hyperechoic amniotic membranes in patients with preterm premature rupture of membranes (p-PROM) and pregnancy outcome

OBJECTIVES

The early identification of women with preterm premature rupture of membranes (p-PROM) who are at higher risk of imminent delivery remains challenging. The aim of our study was to evaluate if an increased echogenicity of the amniotic membranes may represent a sonographic marker of impending delivery in women with p-PROM.

METHODS

This was a prospective study including women with singleton pregnancies and diagnosis of p-PROM between 22 and 37 gestational weeks. A sonographic examination was performed within 24 h from the hospital admission and the appearance of the amniotic membranes close to the internal os was specifically evaluated. The membranes were defined as hyperechoic when their echogenicity was similar to that of the fetal bones or normoechoic in the other cases. The primary aim of the study was to compare the admission to spontaneous onset of labor interval and the pregnancy outcome between the cases of p-PROM with and without hyperechoic membranes.

RESULTS

Overall, 45 women fulfilled the inclusion criteria with similar characteristics at admission. In women with hyperechoic membranes, the admission to spontaneous onset of labor interval was significantly shorter (11.5 [5.3-25.0] vs. 3.0 [1.5-9.0] p=0.04) compared to women with normo-echoic membranes. At binomial logistic regression after adjustment for GA at hospital admission, the presence of hyperechoic membranes was found as the only independent predictor of spontaneous onset of labor ≤72 h (aOR: 6.1; 95% CI: 1.0-36.9).

CONCLUSIONS

The presence of hyperechoic membranes is associated with a 6-fold higher incidence of spontaneous onset of labor within 72 h independently from the gestational age at p-PROM.

Comparison of sonographic fetal weight estimation formulas in patients with preterm premature rupture of membranes

BACKGROUND

Estimation of fetal weight (EFW) by ultrasound is useful in clinical decision-making. Numerous formulas for EFW have been published but have not been validated in pregnancies complicated by preterm premature rupture of membranes (PPROM). The purpose of this study is to compare the accuracy of EFW formulas in patients with PPROM, and to further evaluate the performance of the most commonly used formula - Hadlock IV.

METHODS

A retrospective cohort study of women with singleton gestations and PPROM, admitted to a single tertiary center between 2005 and 2017 from 22^0/7-33^0/7 (n = 565). All women had an EFW within 14 days of delivery by standard biometry (biparietal diameter, head circumference, abdominal circumference and femur length). The accuracy of previously published 21 estimated EFW formulas was assessed by comparing the Pearson correlation with actual birth weight, and calculating the random error, systematic error, proportion of estimates within 10% of birth weight, and Euclidean distance.

RESULTS

The mean gestational was 26.8 ± 2.4 weeks at admission, and 28.2 ± 2.6 weeks at delivery. Most formulas were strongly correlated with actual birth weight (r > 0.9 for 19/21 formulas). Mean systematic error was - 4.30% and mean random error was 14.5%. The highest performing formula, by the highest proportion of estimates and lowest Euclidean distance was Ott (1986), which uses abdominal and head circumferences, and femur length. However, there were minimal difference with all of the first 10 ranking formulas. The Pearson correlation coefficient for the Hadlock IV formula was strong at r = 0.935 (p < 0.001), with 319 (56.5%) of measurements falling within 10%, 408 (72.2%) within 15% and 455 (80.5%) within 20% of actual birth weight. This correlation was unaffected by gender (r = 0.936 for males, r = 0.932 for females, p < 0.001 for both) or by amniotic fluid level (r = 0.935 for mean vertical pocket < 2 cm, r = 0.943 for mean vertical pocket ≥2 cm, p < 0.001 for both).

CONCLUSIONS

In women with singleton gestation and PPROM, the Ott (1986) formula for EFW was the most accurate, yet all of the top ten ranking formulas performed quite well. The commonly used Hadlock IV performed quite similarly to Ott's formula, and is acceptable to use in this specific setting.

Antenatal Monitoring After Preterm Prelabor Rupture of Membranes

Preterm prelabor rupture of membranes is a complication of pregnancy with significant associated maternal and fetal risks. Expectant management of this complication requires inpatient admission with close monitoring of maternal and fetal status until delivery. Close antepartum monitoring ensures rapid intervention if indicated, allowing for best possible maternal and neonatal outcomes.

Perinatal Outcomes Associated with Latency in Late Preterm Premature Rupture of Membranes

This study aims to evaluate the perinatal outcomes of preterm premature rupture of membrane (PPROM) with latency periods at 33 + 0-36 + 6 weeks of gestation. This retrospective case-control study included women with singleton pregnancies who delivered at 33 + 0-36 + 6 weeks at Korea University Ansan Hospital in South Korea between 2006-2019. The maternal and neonatal characteristics were compared between different latency periods (expectant delivery ≥72 h vs. immediate delivery <72 h). Data were compared among 345 women (expectant, n = 39; immediate delivery, n = 306). There was no significant difference in maternal and neonatal morbidities between the groups, despite the younger gestational age in the expectant delivery group. Stratified by gestational weeks, the 34-week infants showed a statistically significant lower exposure to antenatal steroids (73.4% vs. 20.0%, p < 0.001), while the incidence of respiratory distress syndrome (12.8%) and the use of any respiratory support (36.8%) was higher than those in the 33-week infants, without significance. Our study shows that a prolonged latency period (≥72 h) did not increase maternal and neonatal morbidities, and a considerable number of preterm infants immediately delivered at 34 weeks experienced respiratory complications. Expectant management and antenatal corticosteroids should be considered in late preterm infants with PPROM.

Transabdominal amniocentesis in expectant management of preterm premature rupture of membranes: A single center prospective study

AIMS

The aim of this study was to evaluate the role of IL-6 point-of-care test in amniotic fluid obtained from serial amniocentesis in expectantly managed women with PPROM between 24 and 34 weeks of gestation.

METHODS

We conducted a prospective observational cohort study which included 62 pregnant women with PPROM in gestational weeks between 22+0 and 34+0. Women aged >18 years were eligible if they presented with PPROM and a singleton pregnancy. Only women who delivered at >24.0 weeks were included in the study. In all women, the maternal blood sampling and a transabdominal amniocentesis were performed at the time of admission prior to the administration of corticosteroids, antibiotics, or tocolytics, to rule out signs of chorioamnionitis. Maternal temperature, maternal serum C-reactive protein (CRP) and white blood cell (WBC) counts were assayed every subsequent day until delivery. Amniotic fluid was used for the clinical assessment (IL-6 point-of-care test, identification of microorganisms in the amniotic fluid. After one week of expectant management of PPROM, second amniocentesis with amniotic fluid sampling was performed in patients who did not deliver. For all newborns, medical records regarding neonatal morbidity and mortality were reviewed.

RESULTS

In total, 62 women aged 19 to 41 years were recruited in the study. The mean gestational age at the time of PPROM was 31+0, the mean gestational age at labor was 32+1, and the median time from PPROM to childbirth was 112 h. IL-6 point-of-care test values above 1,000 pg/mL (positive Il-6 AMC) were found in 12 women (19.4%) with median interval from PPROM to childbirth 56 h (min-max: 6.4-288). IL-6 point-of-care test values below 1,000 pg/mL (negative Il-6 AMC) were found in 51 women (81.0%). The neonatal mortality rate was 1.9% and was associated with prematurity.

CONCLUSION

The major clinical finding of our study is that serial transabdominal amniocentesis with Il-6 point-of-care test helps to identify a high inflammatory status in amniotic fluid in women with PPROM. Subsequent expectant management of women with PPROM does not lead to worsening of short-term neonatal outcomes.