Predicting preterm delivery in asymptomatic patients with prior preterm delivery by measurement of cervical length and phosphorylated insulin-like growth factor-binding protein-1

Microbial and human transcriptome in vaginal fluid at midgestation: Association with spontaneous preterm delivery

BACKGROUND

Intrauterine infection and inflammation caused by microbial transfer from the vagina are believed to be important factors causing spontaneous preterm delivery (PTD). Multiple studies have examined the relationship between the cervicovaginal microbiome and spontaneous PTD with divergent results. Most studies have applied a DNA-based assessment, providing information on the microbial composition but not transcriptional activity. A transcriptomic approach was applied to investigate differences in the active vaginal microbiome and human transcriptome at midgestation between women delivering spontaneously preterm versus those delivering at term.

METHODS

Vaginal swabs were collected in women with a singleton pregnancy at 18 + 0 to 20 + 6 gestational weeks. For each case of spontaneous PTD (delivery <37 + 0 weeks) two term controls were randomized (39 + 0 to 40 + 6 weeks). Vaginal specimens were subject to sequencing of both human and microbial RNA. Microbial reads were taxonomically classified using Kraken2 and RefSeq as a reference. Statistical analyses were performed using DESeq2. GSEA and HUMAnN3 were used for pathway analyses.

RESULTS

We found 17 human genes to be differentially expressed (false discovery rate, FDR < 0.05) in the preterm group (n = 48) compared to the term group (n = 96). Gene expression of kallikrein-2 (KLK2), KLK3 and four isoforms of metallothioneins 1 (MT1s) was higher in the preterm group (FDR < 0.05). We found 11 individual bacterial species to be differentially expressed (FDR < 0.05), most with a low occurrence. No statistically significant differences in bacterial load, diversity or microbial community state types were found between the groups.

CONCLUSIONS

In our mainly white population, primarily bacterial species of low occurrence were differentially expressed at midgestation in women who delivered preterm versus at term. However, the expression of specific human transcripts including KLK2, KLK3 and several isoforms of MT1s was higher in preterm cases. This is of interest, because these genes may be involved in critical inflammatory pathways associated with spontaneous PTD.

Methods of detection and prevention of preterm labour and the PAMG-1 detection test: a review

OBJECTIVES

Preterm labour is the leading cause of hospitalization during pregnancy. In France, it results in more than 60,000 births before 37 weeks of gestation every year. Recent studies suggest that detection of placental α-microglobulin-1 (PAMG-1) in vaginal secretions among women presenting symptoms of preterm labour with intact membranes has good predictive value for the onset of spontaneous preterm delivery within 7 days. The test is especially interesting, in that the repetition of antenatal corticosteroids for foetal lung maturation is no longer recommended in France and the effect of the initial administration is most beneficial in the 24 h to 7 days afterwards.

METHODS

We included all studies listed in PubMed and clinicaltrials.gov with the terms "PAMG-1" and either "preterm labor" or "preterm labour", while excluding all studies on the subject of "rupture of the membranes" from 2000 through 2017. Ten studies were thus included.

RESULTS

In women who had both the PAMG-1 and foetal fibronectin test, the PAMG-1 test was statistically superior to the measurement of cervical length for positive predictive value (p<0.0074), negative predictive value (p=0.0169) and specificity (p<0.001) for the prediction of spontaneous preterm delivery within 7 days.

CONCLUSIONS

The use of PAMG-1 may make it possible to target the women at risk with a shortened cervix on ultrasound (<25 mm) those with an imminent preterm delivery and therefore to adapt management, especially the administration of antenatal corticosteroid therapy.

Adiponectin as a Potential Biomarker for Pregnancy Disorders

Adiponectin is an adipocyte-derived hormone that plays a critical role in energy homeostasis, mainly attributed to its insulin-sensitizing properties. Accumulating studies have reported that adiponectin concentrations are decreased during metabolic diseases, such as obesity and type 2 diabetes, with an emerging body of evidence providing support for its use as a biomarker for pregnancy complications. The identification of maternal factors that could predict the outcome of compromised pregnancies could act as valuable tools that allow the early recognition of high-risk pregnancies, facilitating close follow-up and prevention of pregnancy complications in mother and child. In this review we consider the role of adiponectin as a potential biomarker of disorders associated with pregnancy. We discuss common disorders associated with pregnancy (gestational diabetes mellitus, preeclampsia, preterm birth and abnormal intrauterine growth) and highlight studies that have investigated the potential of adiponectin to serve as biomarkers for these disorders. We conclude the review by recommending strategies to consider for future research.

The value of a vaginal sample for detecting PAMG-1 (Partosure®) in women with a threatened preterm delivery (the MAPOSURE Study): protocol for a multicenter prospective study

BACKGROUND

Threatened preterm delivery (TPD) is the leading cause of inpatient admissions during pregnancy. The ability to predict the risk of imminent preterm delivery is thus a major priority in obstetrics. The aim of our study is to assess the diagnostic performance of the test to detect the placental alpha microglobulin 1 (PAMG-1) for the prediction of delivery within 7 days in women with TPD.

METHODS

This is a prospective multicenter diagnostic study. Inclusion criteria are singleton pregnancy, gestational age between 24 + 0 and 33 + 6 weeks inclusive, cervical measurement 25 mm or less assessed by transvaginal ultrasound (with or without uterine contractions), clinically intact membranes and cervical dilatation < 3 cm assessed by digital examination. According to the current protocol, when a women presents with TPD and the diagnosis is confirmed by transvaginal ultrasound, a vaginal sample to test for genital infection is performed. At the same time, the midwife will perform the PartoSure® test. To perform this analysis, a sample of cervicovaginal secretions is taken with the vaginal swab furnished in the test kit. The primary outcome is the specificity of the PartoSure® test of women who gave birth more than 7 days after their hospitalization for TPD. The secondary outcomes are the sensitivity, PPV, and NPV of the Partosure® test and the factors associated with false positives (with a univariate logistic regression model). Starting with the hypothesis of an anticipated specificity of 89%, if we want to estimate this specificity with a confidence interval of ± 5%, we will require 151 women who do not give birth within 7 days. We therefore decided to include 400 women over a period of two years to have a larger number of events (deliveries within 7 days).

DISCUSSION

The different tests already used such as fetal fibronectin and phIGFBP-1, are not sufficiently relevant to recommend their use in daily practice. The different studies of PAMG-1 described above thus provide support for the use of this substance, tested by PartoSure®. Nonetheless, other larger studies are necessary to validate its use in daily practice and our study could answer this question.

TRIAL REGISTRATION

NCT03401255 (January 15, 2018).

Using an innovative stacked ensemble algorithm for the accurate prediction of preterm birth

Objective:

A birth before the normal term of 38 weeks of gestation is called a preterm birth (PTB). It is one of the major reasons for neonatal death. The objective of this article was to predict PTB well in advance so that it was converted to a term birth.

Material and Methods:

This study uses the historical data of expectant mothers and an innovative stacked ensemble (SE) algorithm to predict PTB. The proposed algorithm stacks classifiers in multiple tiers. The accuracy of the classiffication is improved in every tier.

Results:

The experimental results from this study show that PTB can be predicted with more than 96% accuracy using innovative SE learning.

Conclusion:

The proposed approach helps physicians in Gynecology and Obstetrics departments to decide whether the expectant mother needs treatment. Treatment can be given to delay the birth only in patients for whom PTB is predicted, or in many cases to convert the PTB to a normal birth. This, in turn, can reduce the mortality of babies due to PTB.

Prediction of spontaneous preterm delivery in women presenting with premature labor: a comparison of placenta alpha microglobulin-1, phosphorylated insulin-like growth factor binding protein-1, and cervical length

BACKGROUND

Placental alpha microglobulin-1 and phosphorylated insulin-like growth factor-binding protein-1 have been studied in patients at risk for preterm birth with signs and symptoms of preterm labor. However, a direct comparison between these 2 biomarkers, alone or in combination with cervical length measurement with an adequate sample size, has been lacking to date.

OBJECTIVE

The purpose of this study was to compare the placental alpha microglobulin-1 test and the phosphorylated insulin-like growth factor-binding protein-1 test alone and in combination with cervical length measurement for the prediction of imminent spontaneous preterm birth of testing in pregnant women with symptoms of preterm labor in a tertiary care setting.

STUDY DESIGN

Four hundred three patients with intact amniotic membranes and cervical dilation ≤3 cm, without recent intercourse or cerclage, between gestational weeks of 20⁺⁰ and 36⁺⁶ were recruited prospectively from 3 international centers. Placental alpha microglobulin-1 and phosphorylated insulin-like growth factor-binding protein-1 tests were conducted before cervical length measurement via transvaginal ultrasound scanning. Caregivers were blinded to the biomarker test results. Medically indicated deliveries within 14 days of testing were excluded. Standard performance statistics with 95% confidence intervals were calculated and compared based on pairwise estimates from a generalized model.

RESULTS

Of 403 subjects who were enrolled in the study cohort, 94% (383/403 women) met the inclusion criteria. Median gestational age and cervical length at presentation were 30⁺⁵ weeks and 27 mm, respectively; 6.8% women (26/383 women) had spontaneous birth ≤7 days from testing. The placental alpha microglobulin-1 test was positive in 7.8% of the women (30/383 women); the phosphorylated insulin-like growth factor-binding protein-1 test was positive in 29.5% women (113/383 women). Positive predictive value for placental alpha microglobulin-1, phosphorylated insulin-like growth factor-binding protein-1, and cervical length <25 mm for the prediction of spontaneous preterm birth in the overall cohort was 60.0% (18/30 women), 18.6% (21/113 women), 11.8% (18/152 women), respectively. The negative predictive value was 97.7% (345/353 women), 98.2% (265/270 women), 96.5% (223/231 women), respectively. The prevalence of spontaneous preterm birth in this group was 6.8% (26/383 women). The positive likelihood ratios were 20.6, 3.1, and 1.8, respectively. The negative likelihood ratio were 0.3, 0.3, and 0.5, respectively. Positive predictive values for placental alpha microglobulin-1 and phosphorylated insulin-like growth factor-binding protein-1 tests in patients with cervical length shortening of 15-30 mm for the prediction of spontaneous preterm birth were 60.9% (14/23 women) and 28.1% (16/57 women), respectively. The negative predictive values were 97.1% (168/173 women) and 97.8% (136/139 women), respectively. The prevalence of spontaneous preterm birth in the 15-30 mm cohort was 9.7% (19/196 women). The positive likelihood ratios were 14.5 and 3.6, respectively. The negative likelihood ratios were 0.3 and 0.2, respectively.

CONCLUSION

Placental alpha microglobulin-1 is significantly more specific than phosphorylated insulin-like growth factor-binding protein-1 for the prediction of spontaneous preterm birth ≤7 days (P<.0001), whereas both tests have comparable sensitivity. In patients with cervical length 15-30 mm, although placental alpha microglobulin-1 has a significantly higher positive predictive value and specificity compared with phosphorylated insulin-like growth factor-binding protein-1 for the prediction of spontaneous preterm birth at ≤7 days (P<.01), both tests have a comparable sensitivity and negative predictive value. In conclusion, placental alpha microglobulin-1 is a better predictor of imminent spontaneous preterm birth when compared with phosphorylated insulin-like growth factor-binding protein-1 alone or in combination with cervical length measurement. In patients with shortening of cervical length of 15-30 mm, the placental alpha microglobulin-1 test is a significantly better predictor of imminent spontaneous preterm birth within 7 days of testing than is phosphorylated insulin-like growth factor-binding protein-1.

Prediction of Delivery in Women with Threatening Preterm Labour using Phosphorylated Insulin-Like Growth Factor Binding Protein-1 and Cervical Length using Transvaginal Ultrasound

INTRODUCTION

Preterm delivery remains a challenge in Obstetrics as it is responsible for significant cause of perinatal morbidity and mortality. At present there is no standard test for prediction of preterm labour for timely referral to a center with NICU facilities.

AIM

To evaluate the effectiveness of the cervical phosphorylated insulin like growth factor binding protein-1(phIGFBP-1), cervical length measurement and combination of phIGFBP-1 with cervical length for Predicting Preterm Labour (PTL).

MATERIALS AND METHODS

It was a observational prospective study done from January 2014 to April 2015 in Department of Obstetrics and Gynaecology, NDMC Medical College and Hindu Rao Hospital, Delhi, India. A total of 100 women with singleton pregnancy, between 24 and 36 weeks of gestation with complaint of uterine contractions were randomly selected. These women were subjected to detect phIGFBP-1 in cervical secretions and cervical length measurement by Transvaginal Sonography (TVS). Result of the test, cervical length and time lapse between test and delivery was noted and the results were analysed. The cervical length less than 25 mm was used as a cut off point for predicting pre-term delivery. Data was analysed using SPSS software version 20.0.

RESULTS

The Negative Predictive Value (NPV) of phIGFBP-1 and cervical length was similar (95.2% vs 94.05%) respectively for prediction of preterm labour within one week of admission and 93.92% vs 94.80% at 37 weeks of gestational age. Combined test had higher NPV of 96.38% at 34 weeks of gestation and 94% within two days of admission. Positive Predictive Value (PPV) was low for both the test and combining the two-test did not have any advantage as far as PPV was concerned. Receiver Operating Characteristic (ROC) curve showed that the combined test had a superior result in predicting PTL compared to either phIGFBP-1 or cervical length. The combined test had steepest ROC curve at < 34 weeks of gestation (AUC-0.83 with 95% CI).

CONCLUSION

The phIGFBP-1 test and cervical length have an almost equivalent ability to predict preterm delivery independently. The combined use of phIGFBP-1 and TVS for cervical length shows an increase in efficacy in predicting preterm labour.

Cervical phosphorylated insulin-like growth factor binding protein-1 test for the prediction of preterm birth: a systematic review and metaanalysis

OBJECTIVE

To assess the accuracy of the cervical phosphorylated insulin-like growth factor binding protein-1 (phIGFBP-1) test to predict preterm birth in women with and without symptoms of preterm labor through the use of formal methods for systematic reviews and metaanalytic techniques.

DATA SOURCES

PubMed, Embase, Cinahl, Lilacs, and Medion (all from inception to June 30, 2015), reference lists, conference proceedings, and Google scholar.

STUDY ELIGIBILITY CRITERIA

Cohort or cross-sectional studies that reported on the predictive accuracy of the cervical phIGFBP-1 test for preterm birth.

STUDY APPRAISAL AND SYNTHESIS METHODS

Two reviewers independently selected studies, assessed the risk of bias, and extracted the data. Summary receiver-operating characteristic curves, pooled sensitivities and specificities, and summary likelihood ratios were generated.

RESULTS

Forty-three studies met the inclusion criteria, of which 15 provided data on asymptomatic women (n = 6583) and 34 on women with an episode of preterm labor (n = 3620). Among asymptomatic women, the predictive accuracy of the cervical phIGFBP-1 test for preterm birth at <37, <34, and <32 weeks of gestation was minimal, with pooled sensitivities and specificities and summary positive and negative likelihood ratios ranging from 14% to 47%, 76% to 93%, 1.5 to 4.4, and 0.6 to 1.0, respectively. Among women with an episode of preterm labor, the test had a low predictive performance for delivery within 7 and 14 days of testing, and preterm birth at <34 and <37 weeks of gestation with pooled sensitivities and specificities and summary positive and negative likelihood ratios that varied between 60% and 68%, 77% and 81%, 2.7 and 3.5, and 0.4 and 0.5, respectively. A negative test result in women with an episode of preterm labor had a low to moderate accuracy to identify women who are not at risk for delivering within the next 48 hours (summary negative likelihood ratio of 0.28 in all women and 0.23 in women with singleton gestations).

CONCLUSION

Cervical phIGFBP-1 has the potential utility to identify patients with an episode of preterm labor who will not deliver within 48 hours. However, its overall predictive ability for the identification of symptomatic and asymptomatic women at risk for preterm birth is limited.

Rapid cervical phIGFBP-1 test in asymptomatic twin pregnancies: role in mid-pregnancy prediction of spontaneous preterm delivery

Objective This study aimed to assess the accuracy of a second-trimester rapid cervical phosphorylated insulin-like growth factor binding protein-1 (phIGFBP-1) test to predict spontaneous preterm delivery in asymptomatic twin pregnancies. Method During the second trimester, a rapid test to detect phIGFBP-1 in cervical secretions was performed on consecutive twin pregnancies between 2009 and 2011, to evaluate its predictive value for spontaneous preterm delivery at <28, <30, <32 and <34 weeks' gestation. Excluded were patients with cerclage, pessary or undergoing indicated preterm delivery. Results A total of 197 pregnancies fulfilled the study criteria and were tested at a median gestational age of 20.3 weeks (interquartile range: 20-20.6). Median gestational age at delivery was 36.4 weeks. Spontaneous preterm delivery at <34 weeks occurred in 21 (10.7%) cases, at <32 weeks in 9 (4.5%), at <30 weeks in 6 (3%) and at <28 weeks in 4 (2%). Seventeen patients (8.7%) were test positive: In this group, three patients delivered before 34 weeks' gestation, whereas none delivered at <32 weeks. The sensitivity, specificity, positive and negative predictive value of the test for spontaneous preterm delivery <34 weeks were 14% (95% confidence interval, 3-37%), 92% (86-95%), 17% (4-44%) and 90% (84-93%), respectively, with a positive and negative likelihood ratio of 1.79 (0.56-5.74) and 0.93 (0.78-1.10). Conclusions In the second trimester, rapid cervical phIGFBP-1 testing in asymptomatic twin pregnancies has a poor performance in predicting spontaneous preterm delivery.

The Actim Partus test to predict pre-term birth in asymptomatic high-risk women

The Actim Partus test has been shown to be a useful predictor of pre-term birth in symptomatic women, but limited research has been carried out in high-risk asymptomatic women. This is a pilot study to evaluate the use of this test as a direct comparator with the fetal fibronectin test. All asymptomatic high-risk women attending a pre-term surveillance clinic over a 9-month period, took an Actim Partus and fetal fibronectin test, between 23(+0)-24(+6) weeks' gestation. A total of 45 women were eligible. The positive and negative predictive values of the Actim Partus test for delivery at ≤ 37 weeks' gestation were 0% and 70%, respectively, compared with the fetal fibronectin test, with values of 67% and 79%, respectively. It was concluded that the Actim Partus test did not perform well as a predictor of pre-term birth in high-risk asymptomatic women.

Transvaginal sonographic evaluation of the cervix in asymptomatic singleton pregnancy and management options in short cervix

Preterm delivery (PTD), defined as birth before 37 completed weeks of gestation, is the leading cause of perinatal morbidity and mortality. Evaluation of the cervical morphology and biometry with transvaginal ultrasonography at 16–24 weeks of gestation is a useful tool to predict the risk of preterm birth in low- and high-risk singleton pregnancies. For instance, a sonographic cervical length (CL) > 30 mm and present cervical gland area have a 96-97% negative predictive value for preterm delivery at <37 weeks. Available evidence supports the use of progesterone to women with cervical length ≤25 mm, irrespective of other risk factors. In women with prior spontaneous PTD with asymptomatic cervical shortening (CL ≤ 25 mm), prophylactic cerclage procedure must be performed and weekly to every two weeks follow-up is essential. This article reviews the evidence in support of the clinical introduction of transvaginal sonography for both the prediction and management of spontaneous preterm labour.

Prediction of preterm birth using the cervical consistency index

OBJECTIVES

To assess the diagnostic power of a new cervical consistency index (CCI) obtained using transvaginal sonography for the prediction of spontaneous preterm birth (PTB) and to establish reference ranges for this new variable.

METHODS

Included in this prospective cross-sectional study were 1115 singleton pregnancies at 5-36 weeks of gestation. Anteroposterior cervical diameter was measured before (AP) and after (AP') application of pressure on the cervix using the transvaginal probe. The index was calculated using the formula: CCI=((AP'/AP) × 100). Cervical length was also measured. The outcomes evaluated were spontaneous PTB before 32, 34 and 37 weeks. Logistic regression and analysis of receiver-operating characteristics (ROC) curves were performed to evaluate the diagnostic power of CCI and cervical length (adjusted for gestational age). Intraclass correlation coefficients (ICCs) and Bland-Altman analysis were used to evaluate intra- and interobserver variability.

RESULTS

In the 1031 women with follow-up, the rate of spontaneous PTB before 32 weeks was 0.87%, before 34 weeks was 2.13% and before 37 weeks was 7.76% (n=80). There were 31 (3.01%) iatrogenic PTBs before 37 weeks. An inverse linear correlation between gestational age and CCI was observed, with regression equation: CCI (in %)=89.8 - 1.35 × (GA in weeks); r(2)=0.66, P<0.001. Cervical length showed an inverse quadratic, though non-significant, relationship with gestational age: CL (in mm)=31.084 - 0.0278× (GA in weeks)(2) + 1.0772× (GA in weeks); r(2)=0.076, P<0.14. The intra- and interobserver ICCs for CCI were 0.99 (95% CI, 0.988-0.994) and 0.98 (95% CI, 0.973-0.987), respectively. The area under the ROC curve for CCI in the prediction of spontaneous PTB before 32 weeks was 0.947, for spontaneous PTB before 34 weeks it was 0.943 and for spontaneous PTB before 37 weeks it was 0.907. For a 5% screen-positive rate, CCI had a sensitivity of 67%, 64% and 45% for prediction of spontaneous PTB before 32, 34 and 37 weeks, respectively, with equivalent values of 11%, 9% and 11% for cervical length.

CONCLUSIONS

CCI shows a clear inverse linear relationship with GA. Assessment of CCI is reproducible and is effective in the prediction of spontaneous PTB. This new variable appears to provide better prediction of spontaneous PTB than does cervical length.

Novel biomarkers for the prediction of the spontaneous preterm birth phenotype: a systematic review and meta-analysis

BACKGROUND

Being able to predict preterm birth is important, as it may allow a high-risk population to be selected for future interventional studies and help in understanding the pathways that lead to preterm birth.

OBJECTIVE

To investigate the accuracy of novel biomarkers to predict spontaneous preterm birth in women with singleton pregnancies and no symptoms of preterm labour.

SEARCH STRATEGY

Electronic searches in PubMed, Embase, Cinahl, Lilacs, and Medion, references of retrieved articles, and conference proceedings. No language restrictions were applied.

SELECTION CRITERIA

Observational studies that evaluated the accuracy of biomarkers proposed in the last decade to predict spontaneous preterm birth in asymptomatic women. We excluded studies in which biomarkers were evaluated in women with preterm labour.

DATA COLLECTION AND ANALYSIS

Two reviewers independently extracted data on study characteristics, quality, and accuracy. Data were arranged in 2 × 2 contingency tables and synthesised separately for spontaneous preterm birth before 32, 34, and 37 weeks of gestation. We used bivariate meta-analysis to estimate pooled sensitivities and specificities, and calculated likelihood ratios (LRs).

MAIN RESULTS

A total of 72 studies, including 89,786 women and evaluating 30 novel biomarkers, met the inclusion criteria. Only three biomarkers (proteome profile and prolactin in cervicovaginal fluid, and matrix metalloproteinase-8 in amniotic fluid) had positive LRs > 10. However, each of these biomarkers was evaluated in only one small study. Four biomarkers had a moderate predictive accuracy (interleukin-6 and angiogenin, in amniotic fluid; human chorionic gonadotrophin and phosphorylated insulin-like growth factor binding protein-1, in cervicovaginal fluid). The remaining biomarkers had low predictive accuracies.

CONCLUSIONS

None of the biomarkers evaluated in this review meet the criteria to be considered a clinically useful test to predict spontaneous preterm birth. Further large, prospective cohort studies are needed to evaluate promising biomarkers such as a proteome profile in cervicovaginal fluid.

The role of insulin-like growth factor in prediction and prevention of preterm delivery

BACKGROUND/AIM

Prediction and prevention of preterm delivery remain great challenge. It is important to include in everyday medical practice determination of certain markers that could help identifying pregnant women with preterm delivery. Insulinlike growth factor (IGF) is involved in the control mechanism of fetal and placental growth and development. The aim of this study was to examine the presence of insulin-like growth factor binding protein 1 (IGFBP-1) in cervicovaginal secretion of pregnant women with symptoms of preterm labor, but with apparently intact fetal membranes and to point out a possible application of the strip test for detection of phlGFBP-1 in diagnosis of preterm premature rupture of total membranes (PPROM) in everyday medical practice.

METHODS

The study was performed at the Department for Obstetrics and Gynecology, Clinical Center of Vojvodina between October 2008 and May 2009. The study included 54 pregnant women between 20-35 weeks of gestation (WG), divided into two groups: the study group (16 pregnant women with symptoms of preterm delivery that gave birth before 37 WG) and the control group (38 pregnant women with the normal course of pregnancy that gave birth on term). In cervicovaginal secretion of the examined pregnant women the level of IGFBP-1 was determined by the immunochromatographic assay with monoclonal antibodies 6303 as a detecting antibody (Actim PROM test, Medix Biochemica, Kauniainen, Finland).

RESULTS

Gestational age (GA) at delivery in the study group was 32.6 WG and in the control group it was 38.4 WG. Weight of newborns in the study group was 2,021 g and in the control group 3,430 g. IGFBP test was positive in 15 women (93.75%) of the study group, while in the control group it was positive only in 1 woman (2.63%).

CONCLUSION

Test on phIGFBP-1 in cervicovaginal mucus was positive in 93.75% women with preterm delivery, suggesting that this test could be used in diagnosis of silent rupture of fetal membranes and in prediction of preterm delivery.

Biochemical markers predicting pre-term delivery in symptomatic patients: phosphorylated insulin-like growth factor binding protein-1 and fetal fibronectin

PURPOSE

The aim of this study was to evaluate the efficacy of the phosphorylated insulin-like growth factor-binding protein (phIGFBP-1) and of the fetal fibronectin test (fFN) in predicting pre-term delivery in symptomatic women.

METHODS

We included 210 symptomatic women at 24-34 weeks' gestation, who underwent the phIGFBP-1 and fFN test. We analyzed the prevalence of pre-term delivery in these patients within 7 days upon admission, before the 34th and the 37th weeks' gestation.

RESULTS

The 3.8% of women delivered within 7 days upon the admission, the 7.6% before 34 weeks and the 16.2% before 37 weeks' gestation. The phIGFBP-1 and fFN test had a high specificity and a high negative predictive value in predicting pre-term delivery within 7 days, before 34 and before 37 weeks' gestation. The logistic regression of phIGFBP-1 was statistically significant in predicting pre-term delivery with an odds ratio of 10.08 <34 weeks' gestation. The multivariate analysis showed that the phIGFBP test had a higher OR <34 weeks' gestation (p < 0.001) and that the two variables were independent and useful in combination to predict pre-term delivery (<37 weeks' gestation).

CONCLUSION

The phIGFBP-1 test may be better that the fFN test in predicting pre-term delivery before 34 weeks' gestation.

The combination of short cervical length and phIGFBP-1 in the prediction of preterm delivery in symptomatic women

OBJECTIVE

To assess the combined use of cervical length and cervical phosphorylated insulin-like growth factor binding protein-1 (phIGFBP-1) in the prediction of preterm delivery in symptomatic women.

METHODS

Cervical length was prospectively measured in 102 consecutive singleton pregnancies with intact membranes and regular contractions at 24-32 weeks, and phIGFBP-1 was assessed in those with a cervix ≤30 mm.

RESULTS

Among women with a cervix >30 mm (n = 42), none delivered <34 weeks or within 7 days. Among women with a cervical length ≤30 mm (n = 60), eight delivered <34 weeks, four of which within 7 days. A positive phIGFBP-1 conferred a significantly increased risk of delivery before 34 weeks in women with a cervix ≤30 mm (likelihood ratio 2.32, 95% confidence interval 1.15-4.67), and a significantly increased risk of delivering within 7 days in the subgroup of women with a cervical length of 20-30 mm (likelihood ratio 3.64, 95% confidence interval 2.20-6.01).

CONCLUSIONS

In symptomatic women with a cervical length >30 mm the risk of preterm delivery is very low. In women with a cervix ≤30 mm, adding phIGFBP-1 assessment may improve the risk assessment for preterm delivery, and help to plan subsequent pregnancy management.

Role of phIGFBP-1 and ultrasound cervical length in predicting pre-term labour

This prospective observational study was to evaluate the efficacy of combining phosphorylated insulin-like growth factor binding protein-1 (phIGFBP-1) and transvaginal ultrasound cervical length (CL) compared with either indicator alone in predicting pre-term labour (PTL). Women with singleton pregnancy between 24 and 36 weeks' gestation with evidence of PTL were subjected to phIGFBP-1 and CL tests. Of the 51 women, five were tested positive (phIGFBP-1 positive and CL <2.5 cm) for combination of phIGFBP-1 and CL (four delivered within 1 week), whereas 46 tested negative, of which, only one delivered. A much higher negative predictivity (NP), positive predictivity (PP) and specificity (SP) in the combination test was seen compared with phIGFBP-1 or CL alone (NP: 97.8% vs 97.7% vs 97.1%; PP: 80.0% vs 51.1% and CL 23.5%; SP: 97.8% vs 93.5% vs 71.1%, respectively). The cervical os dilatation of 2 cm with combined positive test (p = 0.001) indicated a higher likelihood of PTL.

Reference ranges for cervical length by transvaginal scan in singleton pregnancies

OBJECTIVE

The aim was to construct a chart for cervical length measured by transvaginal ultrasound.

RESEARCH DESIGN AND METHODS

Singleton pregnant women underwent a transvaginal scan to measure the cervical length (CxL) from 20 to 34 weeks. Exclusion criteria were preterm delivery, preterm rupture of membranes, multiple pregnancies, cerclage, and those who have taken vaginal progesterone. For statistical evaluation, we used regression analysis and calculation of 5th, 50th, and 95th centiles was performed.

RESULTS

In the 1061 women with follow up, there were 94 (8.8%) spontaneous and 27 (2.5%) iatrogenic preterm delivery before 37 weeks. The CxL decreased with gestational age (r(2) = 0.0799). The coefficient for the interpolated median is y = 37.754 - 0.0148 x (GA)(2) + 0.2556 x (GA) (r(2) = 0.7247); for the 5th centile is y = 5.9171 - 0.0467 x (GA)(2) + 1.7059 x (GA) (r(2) = 0.6502); and for the 95th centile is y = 114.72 + 0.0758 x (GA)(2) - 4.6706 x (GA) (r(2) = 0.7783).

CONCLUSION

CxL shortened throughout the pregnancy. The chart present 5th, 50th, and 95th centile, respectively, at 23 weeks of 20 mm, 36 mm, and 47 mm; at 28 weeks of 17 mm, 33 mm, and 43 mm; and at 34 weeks of 10 mm, 29 mm, and 43 mm.

Phosphorylated insulin-like growth factor binding protein-1 and cervical measurement in women with threatening preterm birth

OBJECTIVE

To assess the efficacy of the cervical phosphorylated insulin-like growth factor binding protein-1 (pIGFBP-1) in combination with cervical length measurement for the prediction of preterm delivery.

DESIGN

Observational prospective study.

SETTING

University Hospital, Spain.

SAMPLE

A total of 276 women between 24 and 34 weeks gestational age complaining of uterine contractions and intact membranes.

METHODS

Transvaginal scan to assess cervical length and cervical swabs for pIGFBP-1 detection.

MAIN OUTCOME MEASURES

Prevalence of preterm delivery within 48 hours and 7 days, delivery at < 32, < 34 weeks, admission-to-delivery interval by cervical length and the presence of pIGFBP-1. Results. The prevalence of preterm delivery at < 34 weeks was 14.1% (39/276) and 7.6% (21/276) at < 32 weeks. Cervical pIGFBP-1 was positive in 38.7% (107/276), whereas cervical length < 15 mm was present in 7.2% (20/276) and was > 30 mm for 64.8% (179/276) of the women. The presence of a positive pIGFBP-1 appeared useful for prediction of delivery before 32 (likelihood ratio (LR) = 2.21, confidence interval (CI): 1.63-3.00) and 34 weeks (LR = 1.76, CI: 1.25-2.41), respectively. Receiver operating characteristic curves were significant for cervical length and pIGFBP-1 for prediction of delivery at < 34 weeks, < 32 weeks, < 48 hours and < 7 days. Combining pIGFBP-1 and cervical length had a median interval that was shorter when both were positive as compared to only one positive or both negative, but the CIs overlapped.

CONCLUSIONS

Both cervical length measurement and pIGFBP-1 are useful for prediction of spontaneous preterm delivery. A pIGFBP-1 positive result associated with cervical length does not improve preterm delivery prediction rates.

Phosphorylated insulin-like growth factor binding protein-1 in cervical secretions and sonographic cervical length in the prediction of spontaneous preterm delivery

OBJECTIVES

The aim of this study was to evaluate the efficacy of the test for the decidual phosphorylated isoform of insulin-like growth factor binding protein-1 (phIGFBP-1) in endocervical secretions in predicting preterm delivery in women with uterine contractions.

METHODS

The study included 210 women with a singleton pregnancy with documented uterine contractions and intact membranes at between 24 and 34 weeks' gestation who underwent the cervicovaginal phIGFBP-1 test and transvaginal sonographic measurement of cervical length. A receiver-operating characteristics (ROC) curve was used to determine the most useful cut-off point for cervical length. A multivariate logistic regression model was used in order to analyze the combination of significant predictive variables for preterm delivery following univariate analysis.

RESULTS

ROC curves indicated that 26 mm was the optimal cut-off value for cervical length in predicting preterm delivery. A cervical length of < 26 mm and the presence of phIGFBP-1 were statistically significant in univariate logistic regression analyses (P < 0.0001) with odds ratios of 16.18 and 9.29 for preterm delivery, respectively. Multivariate analysis of cervical length and phIGFBP-1 showed that they were independent and therefore useful in combination for predicting preterm delivery.

CONCLUSIONS

Cervical length and the phIGFBP-1 test are independent variables that can be used together to predict preterm delivery in women with uterine contractions. A sonographically measured cervical length of > 26 mm with a negative phIGFBP-1 test in a patient with regular uterine contractions before 37 weeks' gestation seems to indicate a low risk of preterm delivery and may therefore allow avoidance of unnecessary therapies.