Prediction of prolonged pregnancy in nulliparous women by transvaginal ultrasonographic measurement of cervical length at 20-24 weeks and 37 weeks

Plasma acute phase proteins as potential predictors of intra-amniotic inflammation and infection in preterm premature rupture of membranes

BACKGROUND

We aimed to investigate the potential of altered levels of various acute phase proteins (APPs) in the plasma, either used alone or in combination with ultrasound-, clinical-, and conventional blood-based tests, for predicting the risk of intra-amniotic inflammation (IAI), microbial invasion of the amniotic cavity (MIAC), histologic chorioamnionitis (HCA), and funisitis in women with preterm premature rupture of membranes (PPROM).

METHODS

A total of 195 consecutive pregnancies involving singleton women with PPROM (at 23 + 0-34 + 0 weeks) who underwent amniocentesis and from whom plasma samples were obtained at amniocentesis were retrospectively included in this study. Amniotic fluid (AF) was cultured to assess the MIAC and analyzed for interleukin (IL)-6 levels to define IAI (AF IL-6 level of ≥2.6 ng/mL). The plasma concentrations of hepcidin, mannose-binding lectin (MBL), pentraxin-2, retinol-binding protein 4 (RBP4), serum amyloid A1 (SAA1), and serpin A1 were determined using ELISA. Ultrasonographic cervical length (CL), neutrophil-to-lymphocyte ratio (NLR), and C-reactive protein levels were measured. IAI/MIAC was defined as IAI, MIAC, or both.

RESULTS

Multivariate logistic regression analyses showed the following: (1) elevated plasma levels of hepcidin and SAA1 and decreased levels of RBP4 in the plasma were independently associated with IAI/MIAC and (2) decreased plasma RBP4 levels were independently associated with funisitis; however, (3) none of the plasma APPs investigated were associated with acute HCA when adjusted for baseline covariates. Using stepwise regression analysis, noninvasive prediction models comprising plasma RBP4 levels, CL, NLR, and gestational age at sampling were proposed, which provided a good prediction of IAI/MIAC and funisitis (area under the curve: 0.80 and 0.72, respectively).

CONCLUSIONS

Hepcidin, RBP4, and SAA1 were identified as potential APP biomarkers in the plasma predictive of IAI/MIAC or funisitis in patients with PPROM. In particular, combination of these APP biomarkers with ultrasound-, clinical-, and conventional blood-based markers can significantly support the diagnosis of IAI/MIAC and funisitis.

Plasma Kallistatin and Progranulin as Predictive Biomarkers of Intraamniotic Inflammation, Microbial Invasion of the Amniotic Cavity, and Composite Neonatal Morbidity/Mortality in Women With Preterm Premature Rupture of Membranes

PROBLEM

To explore the clinical utility of nine inflammatory immune-, adhesion-, and extracellular matrix-related mediators in the plasma for predicting intraamniotic inflammation and/or microbial invasion of the amniotic cavity (IAI/MIAC) and composite neonatal morbidity and/or mortality (CNMM) in women with preterm premature rupture of membranes (PPROM) when used alone or in combination with conventional blood-, ultrasound-, and clinical-based factors.

METHODS OF STUDY

This retrospective cohort comprised 173 singleton pregnant women with PPROM (24 + 0 - 33 + 6 weeks), who underwent amniocentesis. Amniotic fluid was cultured for microorganisms and assayed for IL-6 levels. Plasma levels of AFP, CXCL14, E-selectin, Gal-3BP, kallistatin, progranulin, P-selectin, TGFBI, and VDBP were determined by ELISA. Ultrasonographic cervical length (CL) and neutrophil-to-lymphocyte ratio (NLR) were measured.

RESULTS

Multivariate logistic regression analyses revealed significant associations between (i) decreased plasma kallistatin levels and IAI/MIAC and (ii) decreased plasma progranulin levels and increased CNMM risk after adjusting for baseline variables (e.g., gestational age at sampling [or delivery] and parity). Using stepwise regression analysis, noninvasive prediction models for IAI/MIAC and CNMM risks were developed, which included plasma progranulin levels, NLR, CL, and gestational age at sampling, and provided a good prediction of the corresponding endpoints (area under the curve: 0.79 and 0.87, respectively).

CONCLUSIONS

Kallistatin and progranulin are potentially valuable plasma biomarkers for predicting IAI/MIAC and CNMM in women with PPROM. Particularly, the combination of these plasma biomarkers with conventional blood-, ultrasound-, and clinical-based factors can significantly support the diagnosis of IAI/MIAC and CNMM.

Antibody microarray analysis of amniotic fluid proteomes in women with cervical insufficiency and short cervix, and their association with pregnancy latency length

Introduction

This study aimed to investigate amniotic fluid (AF) proteins that were differentially expressed between patients with cervical insufficiency (CI) and asymptomatic short cervix (SCX, ≤ 25 mm), and whether these proteins could be predictive of spontaneous preterm birth (SPTB) in these patients.

Method

This was a retrospective cohort study of 129 singleton pregnant women with CI (n = 80) or SCX (n = 49) at 17 to 26 weeks who underwent amniocentesis. An antibody microarray was used to perform comparative proteomic profiling of AF from matched CI (n = 20) and SCX (n = 20) pregnancies. In the total cohort, an ELISA validation study was performed for 15 candidate proteins of interest. Subgroup analyses of patients with CI and SCX were conducted to evaluate the association between the 15 proteins and SPTB at < 32 weeks of gestation.

Results

Eighty-six proteins showed intergroup differences. ELISA validation confirmed significantly higher levels of AF EN-RAGE, IL-8, lipocalin-2, MMP-9, S100A8/A9, thrombospondin-2, and TNFR2 in patients with CI than in those with SCX. Multivariable analysis showed that increased AF levels of EN-RAGE, S100A8/A9, and uPA were independently associated with SPTB at < 32 weeks in patients with CI; whereas in patients with SCX, high AF levels of APRIL, EN-RAGE, LBP, and TNFR2 were independently associated with SPTB at < 32 weeks.

Conclusions

Multiple AF proteins show altered expression in patients with CI compared with SCX controls. Moreover, several novel mediators involved in inflammation were identified as potential biomarkers for predicting SPTB after the diagnosis of CI and SCX. These results provide new insights into target-specific molecules for targeted therapies to prevent SPTB in patients with CI/SCX.

Protein microarray analysis of amniotic fluid proteins associated with spontaneous preterm birth in women with preterm labor

PROBLEM

To identify proteins present in the amniotic fluid (AF) that could be associated with spontaneous preterm birth (SPTB; delivery < 7 days) in women with preterm labor (PTL).

METHOD OF STUDY

First, the AF proteome of 20 women with PTL and SPTB was compared with that of 20 matched women with term deliveries using an antibody microarray. Next, nine identified candidate biomarkers of SPTB were further validated in 267 singleton pregnant women with PTL who underwent amniocentesis at 26-33 weeks of gestation using ELISA, and whether the degree of expression of these proteins was associated with the risk severity for subsequent SPTB was retrospectively assessed.

RESULTS

Of the 507 proteins evaluated in the microarray analysis, 27 displayed significant intergroup differences. In particular, ELISA quantification confirmed that the expression of EN-RAGE, IL-6, IL-8, IP-10, lipocalin-2, MMP-8, MMP-9, S100 A8/A9, and TNFR2 were all increased in the AF of women spontaneously delivering within 7 days of sampling compared with those delivering after 7 days. Moreover, the odds of SPTB within 7 days, even upon adjusting for confounders, tended to significantly increase with each increasing quartile of baseline AF levels of each protein (P-value for trend < .05).

CONCLUSION

Nine AF proteins were found to be independently associated with higher risk of subsequent SPTB in women with PTL, all of which were immune-, inflammation-, and extracellular matrix-related proteins. Moreover, risk severity for this subsequent SPTB is closely related to the degree of expression of each of these proteins.

The value of measuring cervical length between 24 and 28 weeks of gestation for predicting the risk of late and post-term pregnancy

OBJECTIVE

The aim of this study was to investigate the value of measuring cervical length (CL) between 24 and 28 weeks of gestation for predicting the risk of late and post-term pregnancy.

METHODS

In this prospective longitudinal study, pregnant women whose CL was measured between 24 and 28 weeks were followed until delivery. The CL was adjusted for confounders and the results are presented using odds ratio and receiver operating characteristic curve (ROC).

RESULTS

A total of 874 women met the inclusion criteria. The median value of CL measured between 24 and 28 weeks was 34.0 mm (30.0-38.0 25%, 75% interquartile range). The risk of late and post-term pregnancy was 5.8 times higher in pregnant women with a CL above 35 mm between the 24 and 28 weeks of gestation (95% CI: 2.65-12.94 adjusted OR = 5.8, p < .001). For pregnancies exceeding the 38th week, it was observed that the duration of the gestation increases as CL values increase.

CONCLUSIONS

In this study, it has been demonstrated that measuring the CL between 24 and 28 weeks of gestation can predict late and post-term pregnancy. Prolonged pregnancy may cause neonatal and fetal complications and anxiety. CL measurement performed in these weeks can help prepare pregnant women for a possible prolonged pregnancy and cope with prolonged pregnancy anxiety.

The Identification of Immune-Related Plasma Proteins Associated with Spontaneous Preterm Delivery and Intra-Amniotic Infection in Women with Premature Cervical Dilation or an Asymptomatic Short Cervix

BACKGROUND

We aimed to investigate whether various immune-related plasma proteins, alone or in combination with conventional clinical risk factors, can predict spontaneous preterm delivery (SPTD) and intra-amniotic infection in women with premature cervical dilation or a short cervix (≤ 25 mm).

METHODS

This retrospective study included 80 asymptomatic women with premature cervical dilation (n = 50) or a short cervix (n = 30), who underwent amniocentesis at 17-29 weeks. Amniotic fluid (AF) was cultured, and maternal plasma was assayed for interleukin (IL)-6, matrix metalloproteinase (MMP)-9, tissue inhibitor of metalloproteinases (TIMP)-1, and complements C3a and C5a, using enzyme-linked immunosorbent assay (ELISA) kits. The primary outcome measures were SPTD at < 32 weeks and positive AF cultures.

RESULTS

The plasma levels of IL-6, C3a, and C5a, but not of MMP-9 and TIMP-1, were significantly higher in women with SPTD at < 32 weeks than in those who delivered at ≥ 32 weeks. The women who delivered at < 32 weeks had more advanced cervical dilatation, and higher rates of antibiotic and tocolytic administration and were less likely to be given vaginal progesterone than those who delivered at ≥ 32 weeks. Using a stepwise regression analysis, a combined prediction model was developed, which included the plasma IL-6 and C3a levels, and cervical dilatation (area under the curve [AUC], 0.901). The AUC for this model was significantly greater than that for any single variable included in the predictive model. In the univariate analysis, plasma IL-6 level was the only significant predictor of intra-amniotic infection.

CONCLUSION

In women with premature cervical dilation or a short cervix, maternal plasma IL-6, C3a, and C5a levels could be useful non-invasive predictors of SPTD at < 32 weeks. A combination of these biomarkers and conventional clinical factors may clearly improve the predictability for SPTD, as compared with the biomarkers alone. An increased plasma level of IL-6 predicted intra-amniotic infection.

The impact of preconception body mass index on cervical length: a prospective cohort study in China

Objective: To assess the relationship between preconception body mass index (BMI) and cervical length (CL).Methods: Data was collected from a prospective cohort study conducted in Beijing, China. A total of 4843 qualified women participated in this study, whose health-related information was recorded at the very beginning and their cervical length was measured with transvaginal ultrasound examination during 22-24 gestational weeks. Logistic regression was used to evaluate the relationship between preconception BMI and cervical length, after adjusting for potential confounders.Results: Of all the participants in the analysis, 580 (12.0%) women had a short cervical length (CL less than 30 mm). After adjusting for the age and parity status, the adjusted odds ratios of short CL for underweight: adjusted OR = 1.28 (95% CI: 1.02, 1.60); overweight: adjusted OR = 0.74 (95% CI: 0.55, 0.99); obesity: adjusted OR = 0.38 (95% CI: 0.17, 0.88) compared with normal weight. The mean CL in underweight, normal weight, overweight and obesity group demonstrated a significant linear increased trend (33.47, 34.16 and 34.96 mm, respectively) (p < .05), dependent of age and parity.Conclusions: This research revealed that low preconception BMI women were more likely to have a short CL.

Complement C3a, But Not C5a, Levels in Amniotic Fluid Are Associated with Intra-amniotic Infection and/or Inflammation and Preterm Delivery in Women with Cervical Insufficiency or an Asymptomatic Short Cervix (≤ 25 mm)

BACKGROUND

We aimed to estimate whether elevated levels of complement C3a and C5a in amniotic fluid (AF) are independently associated with increased risks of intra-amniotic infection and/or inflammation (IAI) and spontaneous preterm delivery (SPTD) in women with cervical insufficiency or a short cervix (≤ 25 mm).

METHODS

We conducted a retrospective cohort study of 96 consecutive women with cervical insufficiency (n = 62) or a short cervix (n = 34) at 17 to 27 weeks, and who underwent an amniocentesis. AF was cultured and analyzed for C3a and C5a by enzyme-linked immunosorbent assay kits. The primary outcome measures were IAI (defined as a positive AF culture and/or an elevated AF interleukin-6 level [≥ 7.6 ng/mL]) and SPTD at < 32 weeks.

RESULTS

In multivariable analysis, AF level of C3a was the only variable significantly associated with IAI, whereas C5a level in AF and serum C-reactive protein level were not associated with IAI. Using SPTD at < 32 weeks as the outcome variable in logistic regression, elevated AF levels of C3a were associated with increased risk of SPTD at < 32 weeks after adjusting for other baseline confounders, whereas elevated AF levels of C5a were not.

CONCLUSION

In women with cervical insufficiency or a short cervix, elevated AF level of C3a, but not C5a, is independently associated with increased risks of IAI and SPTD at < 32 weeks. These findings suggest that subclinical IAI or SPTD in the context of cervical insufficiency is related to activation of complement system in AF.

Plasma inflammatory and immune proteins as predictors of intra-amniotic infection and spontaneous preterm delivery in women with preterm labor: a retrospective study

Background

We investigated whether various inflammatory and immune proteins in plasma predict intra-amniotic infection and imminent preterm delivery in women with preterm labor and compared their predictive ability with that of amniotic fluid (AF) interleukin (IL)-6 and serum C-reactive protein (CRP).

Methods

This retrospective cohort study included 173 consecutive women with preterm labor who underwent amniocentesis for diagnosis of infection and/or inflammation in the AF. The AF was cultured, and assayed for IL-6. CRP levels and cervical length by transvaginal ultrasound were measured at the time of amniocentesis. The stored maternal plasma was assayed for IL-6, matrix metalloproteinase (MMP)-9, and complements C3a and C5a using ELISA kits. The primary and secondary outcome criteria were positive AF cultures and spontaneous preterm delivery (SPTD) within 48 h, respectively. Univariate, multivariate, and receiver operating characteristic analysis were used for the statistical analysis.

Results

In bivariate analyses, elevated plasma IL-6 level was significantly associated with intra-amniotic infection and imminent preterm delivery, whereas elevated plasma levels of MMP-9, C3a, and C5a were not associated with these two outcomes. On multivariate analyses, an elevated plasma IL-6 level was significantly associated with intra-amniotic infection and imminent preterm delivery after adjusting for confounders, including high serum CRP levels and short cervical length. In predicting intra-amniotic infection, the area under the curve (AUC) was significantly lower for plasma IL-6 than for AF IL-6 but was similar to that for serum CRP. Differences in the AUCs between plasma IL-6, AF IL-6, and serum CRP were not statistically significant in predicting imminent preterm delivery.

Conclusions

Maternal plasma IL-6 independently predicts intra-amniotic infection in women with preterm labor; however, it has worse diagnostic performance than that of AF IL-6 and similar performance to that of serum CRP. To predict imminent preterm delivery, plasma IL-6 had an overall diagnostic performance similar to that of AF IL-6 and serum CRP. Plasma MMP-9, C3a, and C5a levels could not predict intra-amniotic infection or imminent preterm delivery.

Non-invasive prediction of preterm birth in women with cervical insufficiency or an asymptomatic short cervix (≤25 mm) by measurement of biomarkers in the cervicovaginal fluid

OBJECTIVE

To determine whether various proteins in the cervicovaginal fluid (CVF) known to be involved in immune regulation, alone or in combination with clinical risk factors, can predict spontaneous preterm delivery (SPTD) in women with cervical insufficiency or a short cervix (≤25 mm).

METHODS

This retrospective cohort study included 62 asymptomatic women with cervical insufficiency (n = 27) or an asymptomatic short cervix (n = 35) at 18-27 weeks. CVF swab samples were taken for assays of vitamin D binding protein (VDBP), interleukin (IL)-8, matrix metalloproteinases (MMP)-9, tissue inhibitor of metalloproteinases (TIMP)-1, and Dickkopf-related protein 3 (DKK3) before cervical examination, and maternal blood was collected for the determination of the C-reactive protein (CRP) level. The primary outcome measurement was SPTD at <32 weeks of gestation. Logistic regression analysis and receiver operating characteristic curves were used for the statistical analyses.

RESULTS

The rate of SPTD at <32 weeks was 40.3% (25/62). The CVF levels of VDBP, TIMP-1, and DKK3, but not IL-8 and MMP-9, were significantly higher in the women who had SPTD at <32 weeks than in those who did not deliver spontaneously at <32 weeks. The women who had SPTD at <32 weeks had a significantly more advanced cervical dilatation at presentation and a higher level of serum CRP. Using the stepwise regression analysis, a prediction model was developed by combining various proteins in the CVF and clinical factors, resulting in the inclusion of cervical dilatation, CVF VDBP, and use of corticosteroids (area under curve, 0.909).

CONCLUSIONS

In women with cervical insufficiency or a short cervix, VDBP, TIMP-1, and DKK3 in the CVF may be useful as non-invasive predictors of SPTD at <32 weeks. A combination of these markers and clinical factors appears to improve the predictability of SPTD compared with the markers alone.

Short cervical lengths initially detected in mid-trimester and early in the third trimester in asymptomatic twin gestations: Association with histologic chorioamnionitis and preterm birth

Objective

To determine whether short cervical lengths (≤20 mm) that were initially detected in mid-trimester and early in the third trimester are independently associated with increased risks of subsequent histologic chorioamnionitis and spontaneous preterm birth (SPTB, defined as a delivery before 34 weeks) in asymptomatic women with twin pregnancies.

Material and methods

This is a prospective study including 292 consecutive asymptomatic women with twin gestations. Cervical length measurements were carried out at 20 to 24 weeks’ gestation and at 28 to 32 weeks’ gestation. Both placentas of each twin pair were examined histologically after delivery. The generalized estimation equations models and logistic regression analysis were used for statistical analyses.

Results

Multivariable generalized estimation equations analysis revealed that short cervical length at mid-trimester was independently associated with an increased risk for subsequent histologic chorioamnionitis, whereas short cervical length initially detected early in the third trimester was not. By using the likelihood of SPTB as an outcome variable, multivariable logistic regression analysis indicated that short mid-trimester cervical length and histologic chorioamnionitis were independently associated with a greater risk for SPTB. Similarly, based on the multivariable analysis, a short third trimester cervical length was independently and significantly associated with a greater risk for SPTB.

Conclusions

In asymptomatic women with twin pregnancies, a short mid-trimester cervical length is independently associated with an increased risk of both subsequent histologic chorioamnionitis and SPTB, whereas a short cervical length initially detected early in the third trimester is independently associated with preterm delivery, but not subsequent histologic chorioamnionitis.

Maternal Characteristics, Short Mid-Trimester Cervical Length, and Preterm Delivery

We aimed to determine the maternal characteristics (demographics, an obstetric history, and prior cervical excisional procedure) associated with a short mid-trimester cervical length (CL, defined as a CL of ≤ 25 mm) and whether having a short cervix explains the association between these maternal characteristics and spontaneous preterm delivery (SPTD, defined as a delivery before 34 weeks). This is a single-center retrospective cohort study of 3,296 consecutive women with a singleton pregnancy who underwent routine CL measurement between 20 and 24 weeks. Data were collected on maternal age, weight, height, parity, obstetric history (nulliparity; a history of at least 1 SPTD; and at least 1 term birth and no preterm birth [low-risk history group]), and prior cervical excisional procedure. In the multivariate regression analysis, an obstetric history, prior cervical excisional procedure, and gestational age at measurement were the variables significantly associated with short CL. In contrast, maternal weight, height, age, and parity were not significantly associated with short CL. By using the likelihood of SPTD as an outcome variable, logistic regression indicated that short CL and obstetric history, but not prior cervical excisional procedure, were significantly associated with SPTD after adjustment for potential confounders. A history of SPTD and prior cervical excisional procedure were associated with an increased risk of a short mid-trimester CL. A history of SPTD, but not prior cervical excisional procedure, is associated with an increased risk of SPTD, independent of a short CL.

The change in cervical length over time as a predictor of preterm delivery in asymptomatic women with twin pregnancies who have a normal mid-trimester cervical length

AIM

To determine whether or not the change in cervical length (CL) over time is valuable in predicting spontaneous preterm delivery (SPTD) in asymptomatic twin pregnancies with a normal mid-trimester CL (>25 mm).

METHODS

This was a prospective study including 190 consecutive asymptomatic twin gestations with a CL>25 mm at 20-24 weeks. The women underwent an initial CL measurement at the time of routine ultrasound examination between 20 and 24 weeks' gestation, followed 4-5 weeks later by a repeat CL measurement. The primary outcome measure was SPTD at <32 completed weeks' gestation. Multicollinearity was a concern in the multivariable model since change in CL and follow-up CL were highly correlated.

RESULTS

The rate of SPTD at <32 weeks was 4.2%. Multiple logistic regression analyses demonstrated that the change in CL and the follow-up CL were significantly associated with SPTD before 32 weeks after adjusting for baseline covariate such as in vitro fertilization. The best cut-off values for the prediction of SPTD at <32 weeks' gestation were 13% for the change in CL with a sensitivity of 87.5% and a specificity of 63.2%. There was no significant difference in the area under the receiver operating characteristic curves between the change in CL and the follow-up CL.

CONCLUSIONS

A greater change in CL is a good predictor of SPTD in asymptomatic twin pregnancies with a normal mid-trimester CL. However, the change in CL cannot provide data beyond the follow-up CL. In the setting of a normal mid-trimester CL, a follow-up CL measurement should be considered in asymptomatic twin pregnancies.

Degree of cervical shortening after initial induction of labor as a predictor of subsequent successful induction

OBJECTIVE

To evaluate whether the degree of cervical length shortening is valuable in predicting the success of serial induction of labor on the second day in women in whom it failed on the first day, and to compare its performance with that of cervical length.

METHODS

This was a prospective observational study. We enrolled 92 consecutive women with singleton gestations at > 34.0 weeks' gestation who failed labor induction on the first day of serial induction. Transvaginal sonographic measurement of cervical length and determination of the Bishop score were undertaken before performing each labor induction on the first and second days.

RESULTS

The overall success rate of labor induction performed on the second day was 65% (60/92). Multiple logistic regression analysis demonstrated that the degree of cervical length shortening and cervical length were significantly associated with the successful induction of labor after adjustment for body mass index, parity, use of prostaglandin and Bishop score. There were no significant differences between areas under the ROC curves for degree of cervical length shortening and cervical length.

CONCLUSIONS

The degree of cervical length shortening is valuable in predicting the success of induction of labor on the second day in women in whom induction failed on the first day. However, compared with sonographic cervical length it is no better at predicting the success of subsequent induction of labor.