Primary predictors of preterm labour

Evaluating the effect of maternal non-communicable disease on adverse pregnancy outcomes and birthweight in Pakistan, a facility based retrospective cohort study

Non-communicable diseases (NCDs) claim 74% of global lives, disproportionately affecting lower and middle-income countries like Pakistan. NCDs may increase the risk of preterm birth (PTB), caesarean section (CS), and low birthweight. This study aims to determine whether the high prevalence of NCDs in Pakistan play a role in the high rates of preterm births, and CS. This retrospective cohort study from Aga Khan University Hospital, Pakistan, investigated effects of pre-existing NCDs on pregnancy outcomes of 817 pregnant women. Medical records were used to generate odds ratios for the risk of PTB, labour outcome and birthweight in women with type 1 and type 2 diabetes, hypertension, asthma and thyroid disorders. Multinomial logistic regression and general linear models were used to adjust for confounding variables using IBM SPSS Statistics (v27). Type 2 diabetes significantly increased the risk of PTB and elective CS (both P < 0.05). Elective CS was significantly increased by hypertension and asthma (both, P < 0.05). Surprisingly, asthma halved the risk of PTB (P < 0.05), while type 1 diabetes significantly increased birthweight from 2832 to 3253g (P < 0.001). In conclusion, pre-existing NCDs increase the risk of negative pregnancy outcomes, including PTB, elective CS and birthweight. Asthma, however reduced PTB and justifies further investigation.

Prediction of Preterm Birth among Infants with Orofacial Cleft Defects

OBJECTIVE

To develop risk prediction models for preterm birth among infants with orofacial clefts.

DESIGN

Data from the Texas Birth Defects Registry for infants with orofacial clefts born between 1999-2014 were used to develop preterm birth predictive models. Logistic regression was used to consider maternal and infant characteristics, and internal validation of the final model was performed using bootstrapping methods. The area under the curve (AUC) statistic was generated to assess model performance, and separate predictive models were built and validated for infants with cleft lip and cleft palate alone. Several secondary analyses were conducted among subgroups of interest.

SETTING

State-wide, population-based Registry data.

PATIENTS/PARTICIPANTS

6774 infants with orofacial clefts born in Texas between 1999-2014.

MAIN OUTCOME MEASURE(S)

Preterm birth among infants with orofacial clefts.

RESULTS

The final predictive model performed modestly, with an optimism-corrected AUC of 0.67 among all infants with orofacial clefts. The optimism-corrected models for cleft lip (with or without cleft palate) and cleft palate alone had similar predictive capability, with AUCs of 0.66 and 0.67, respectively. Secondary analyses had similar results, but the model among infants with delivery prior to 32 weeks demonstrated higher optimism-corrected predictive capability (AUC = 0.74).

CONCLUSIONS

This study provides a first step towards predicting preterm birth risk among infants with orofacial clefts. Identifying pregnancies affected by orofacial clefts at the highest risk for preterm birth may lead to new avenues for improving outcomes among these infants.

First Trimester Prediction of Preterm Birth in Patient Plasma with Machine-Learning-Guided Raman Spectroscopy and Metabolomics

Preterm birth (PTB) is the leading cause of infant deaths globally. Current clinical measures often fail to identify women who may deliver preterm. Therefore, accurate screening tools are imperative for early prediction of PTB. Here, we show that Raman spectroscopy is a promising tool for studying biological interfaces, and we examine differences in the maternal metabolome of the first trimester plasma of PTB patients and those that delivered at term (healthy). We identified fifteen statistically significant metabolites that are predictive of the onset of PTB. Mass spectrometry metabolomics validates the Raman findings identifying key metabolic pathways that are enriched in PTB. We also show that patient clinical information alone and protein quantification of standard inflammatory cytokines both fail to identify PTB patients. We show for the first time that synergistic integration of Raman and clinical data guided with machine learning results in an unprecedented 85.1% accuracy of risk stratification of PTB in the first trimester that is currently not possible clinically. Correlations between metabolites and clinical features highlight the body mass index and maternal age as contributors of metabolic rewiring. Our findings show that Raman spectral screening may complement current prenatal care for early prediction of PTB, and our approach can be translated to other patient-specific biological interfaces.

Three biomarker tests to help diagnose preterm labour: a systematic review and economic evaluation

BACKGROUND

Preterm birth may result in short- and long-term health problems for the child. Accurate diagnoses of preterm births could prevent unnecessary (or ensure appropriate) admissions into hospitals or transfers to specialist units.

OBJECTIVES

The purpose of this report is to assess the test accuracy, clinical effectiveness and cost-effectiveness of the diagnostic tests PartoSure™ (Parsagen Diagnostics Inc., Boston, MA, USA), Actim^® Partus (Medix Biochemica, Espoo, Finland) and the Rapid Fetal Fibronectin (fFN)^® 10Q Cassette Kit (Hologic, Inc., Marlborough, MA, USA) at thresholds ≠50 ng/ml [quantitative fFN (qfFN)] for women presenting with signs and symptoms of preterm labour relative to fFN at 50 ng/ml.

METHODS

Systematic reviews of the published literature were conducted for diagnostic test accuracy (DTA) studies of PartoSure, Actim Partus and qfFN for predicting preterm birth, the clinical effectiveness following treatment decisions informed by test results and economic evaluations of the tests. A model-based economic evaluation was also conducted to extrapolate long-term outcomes from the results of the diagnostic tests. The model followed the structure of the model that informed the 2015 National Institute for Health and Care Excellence guidelines on preterm labour diagnosis and treatment, but with antenatal steroids use, as opposed to tocolysis, driving health outcomes.

RESULTS

Twenty studies were identified evaluating DTA against the reference standard of delivery within 7 days and seven studies were identified evaluating DTA against the reference standard of delivery within 48 hours. Two studies assessed two of the index tests within the same population. One study demonstrated that depending on the threshold used, qfFN was more or less accurate than Actim Partus, whereas the other indicated little difference between PartoSure and Actim Partus. No study assessing qfFN and PartoSure in the same population was identified. The test accuracy results from the other included studies revealed a high level of uncertainty, primarily attributable to substantial methodological, clinical and statistical heterogeneity between studies. No study compared all three tests simultaneously. No clinical effectiveness studies evaluating any of the three biomarker tests were identified. One partial economic evaluation was identified for predicting preterm birth. It assessed the number needed to treat to prevent a respiratory distress syndrome case with a 'treat-all' strategy, relative to testing with qualitative fFN. Because of the lack of data, our de novo model involved the assumption that management of pregnant women fully adhered to the results of the tests. In the base-case analysis for a woman at 30 weeks' gestation, Actim Partus had lower health-care costs and fewer quality-adjusted life-years (QALYs) than qfFN at 50 ng/ml, reducing costs at a rate of £56,030 per QALY lost compared with qfFN at 50 ng/ml. PartoSure is less costly than Actim Partus while being equally effective, but this is based on diagnostic accuracy data from a small study. Treatment with qfFN at 200 ng/ml and 500 ng/ml resulted in lower cost savings per QALY lost relative to fFN at 50 ng/ml than treatment with Actim Partus. In contrast, qfFN at 10 ng/ml increased QALYs, by 0.002, and had a cost per QALY gained of £140,267 relative to fFN at 50 ng/ml. Similar qualitative results were obtained for women presenting at different gestational ages.

CONCLUSION

There is a high degree of uncertainty surrounding the test accuracy and cost-effectiveness results. We are aware of four ongoing UK trials, two of which plan to enrol > 1000 participants. The results of these trials may significantly alter the findings presented here.

STUDY REGISTRATION

The study is registered as PROSPERO CRD42017072696.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

Extremely low birth weight influences the relationship between stress and telomere length in adulthood

This study examined the link between two biological markers of stress vulnerability at 22-26 years of age and telomere length at 30-35 among extremely low birth weight (ELBW; <1000 g) survivors and normal birth weight (NBW; >2500 g) control participants. Sixteen ELBW and 22 NBW participants provided baseline afternoon salivary cortisol samples and resting frontal electroencephalogram (EEG) alpha asymmetry data at 22-26 years. Buccal cells were assayed for telomere length at 30-35 years. Analyses controlled for sex, postnatal steroid exposure, childhood socioeconomic status, time of cortisol sample collection, and body mass index at 22-26 years. Salivary cortisol and frontal asymmetry at age 22-26 independently predicted telomere length at age 30-35, such that relatively higher cortisol and greater relative right frontal asymmetry at rest predicted telomere shortening among NBW controls, but not among ELBW survivors. However, similar associations were not noted in ELBW survivors, suggesting that ELBW survivors may have different mechanisms of stress coping as a result of their early-life exposures. These findings offer preliminary evidence in support of the role of stress in the genesis of cellular senescence at least among those born at NBW, but that these links may differ in those born preterm.

Vaginal Biomarkers That Predict Cervical Length and Dominant Bacteria in the Vaginal Microbiomes of Pregnant Women

In many impoverished regions of the world, it may not be possible to assess two major risk factors for preterm birth: a short cervical length and the depletion of vaginal lactobacilli. We determined whether measuring specific compounds in vaginal fluid might be a simple, noninvasive, and cost-effective way to predict the bacteria that dominate the vaginal microbiome and indicate the presence of a shortened cervix (<25 mm). Vaginal fluid samples were prospectively collected from mid-trimester pregnant women, and the concentrations of d- and l-lactic acid, tissue inhibitor of matrix metalloproteinases TIMP-1 and TIMP-2, matrix metalloproteinases MMP-2 and MMP-8, the 70-kDa heat shock protein, a2 isoform of vacuolar ATPase, and sequestrome-1 were quantified by an enzyme-linked immunosorbent assay (ELISA). The compositions of vaginal microbiomes were assessed by analysis of the V1-V3 regions of 16S rRNA genes, while cervical length was determined by transvaginal ultrasonography. The vaginal microbiomes could be clustered into five community state types (CSTs), four of which were dominated by a single Lactobacillus species. The dominance of Lactobacillus crispatus or Lactobacillus jensenii in the vaginal microbiome predicted the level of d-lactic acid present. Several of the biomarkers, especially TIMP-1, in combination with the subject's age and race, were significantly associated with cervical length. Using piecewise structural equation modeling, we established a causal network that links CST to cervical length via biomarkers. We concluded that measuring levels of TIMP-1 and d-lactic acid in vaginal secretions might be a straightforward way to assess the risk for preterm birth due to a short cervix and microbiome composition.IMPORTANCE Premature birth and its complications are the largest contributors to infant death in the United States and globally. A short cervical length and the depletion of Lactobacillus species are known risk factors for preterm birth. However, in many resource-poor areas of the world, the technology to test for their occurrence is unavailable, and pregnant women with these risk factors are neither identified nor treated. In this study, we used path analysis to gain an unprecedented understanding of interactions between vaginal microbiome composition, the concentrations of various compounds in vaginal secretions, and cervical length. We identified low-cost point-of-care measures that might be used to identify pregnant women at risk for preterm birth. The use of these measures coupled with appropriate preventative or treatment strategies could reduce the incidence of preterm births in poor areas of the world that lack access to more sophisticated diagnostic methods.

A case control study of risk factors and neonatal outcomes of preterm birth

OBJECTIVE

The aim is to examine risk factors and neonatal outcomes of preterm birth and to provide basis in preventing preterm birth.

MATERIALS AND METHODS

we carried out our study on 1328 term controls and 1328 preterm birth cases. By using multivariable logistic regression procedures we estimated odds ratio (OR) of potential preterm birth risk factors. T-test and chi-square test were used to estimate differences between groups.

RESULTS

Maternal age, prior history of pregnancy and abortion, prenatal care, complications of pregnancy (includes hypertension, intrahepatic cholestasis of pregnancy (ICP), fetal growth restriction (FGR), premature rupture of the membranes (PROM), placenta previa, abnormal presentation, abnormal S/D ratio et al.) were significantly associated with preterm birth. Several factors emerged as being statistically significant risk factors for preterm birth, such as prior history of pregnancy, hypertension, ICP, FGR, PROM, placenta previa and abnormal presentation. The time of prenatal care was shown to be a protective factor. Additionally, we observed evidence suggested that male babies are known to have a significant higher risk of preterm birth than female babies.

CONCLUSION

Prior history of pregnancy, hypertension, ICP, FGR, PROM, placenta previa and abnormal presentation were covariates identified in this study as risk factors for preterm birth. Preterm birth is an important reason of neonatal poor prognosis and death.

The review of results of foetal fibronectin at the Royal Cornwall Hospital Treliske

The manufacturer of a popular qualitative fFN assay, changed to using a quantitative assay following results from EQUIPPE study. The objective of our study was to compare our hospital data collated from our qualitative fFN assay with EQUIPPE's data, with a view to establish its validity in our hospital. We undertook a retrospective study over a 22-month period to review the data of 432 preterm pregnant women at less than 34 weeks of gestation, who presented to the labour ward with symptoms of threatened preterm labour warranting a fFN test. None of the patient with results between 11 and 199 ng/mL delivered within 7 days. However, there was a rise in percentage of delivery at higher levels. For example, 73% of patients with levels greater or equal to 500 ng/mL delivered within 7 days. Our results are comparable with those of the EQUIPPE study. This has led to changes that could potentially save our hospital money. Impact statement What is already known on this subject? The fFN test is a well validated test used to diagnose a preterm delivery. Most units are changing from the qualitative assays that just show positive or negative results to quantitative assays that give specific numeric values. Manufacturers give a numeric range for positive and negative results. What do the results of this study add? Although our study is local to our population, our findings show that potentially more money could be saved and fewer women separated from their families, if the negative level of the fFN test is increased (following a review of their local practice). What are the implications of these findings for clinical practice and/or further research? More units should review or audit their fFN results and choose what levels to use as a cut off for the test locally. More importantly, a multicentre research is needed to validate if the negative level needs increasing from 49 ng/mL.

Prediction models for the risk of spontaneous preterm birth based on maternal characteristics: a systematic review and independent external validation

Introduction

Prediction models may contribute to personalized risk‐based management of women at high risk of spontaneous preterm delivery. Although prediction models are published frequently, often with promising results, external validation generally is lacking. We performed a systematic review of prediction models for the risk of spontaneous preterm birth based on routine clinical parameters. Additionally, we externally validated and evaluated the clinical potential of the models.

Material and methods

Prediction models based on routinely collected maternal parameters obtainable during first 16 weeks of gestation were eligible for selection. Risk of bias was assessed according to the CHARMS guidelines. We validated the selected models in a Dutch multicenter prospective cohort study comprising 2614 unselected pregnant women. Information on predictors was obtained by a web‐based questionnaire. Predictive performance of the models was quantified by the area under the receiver operating characteristic curve (AUC) and calibration plots for the outcomes spontaneous preterm birth <37 weeks and <34 weeks of gestation. Clinical value was evaluated by means of decision curve analysis and calculating classification accuracy for different risk thresholds.

Results

Four studies describing five prediction models fulfilled the eligibility criteria. Risk of bias assessment revealed a moderate to high risk of bias in three studies. The AUC of the models ranged from 0.54 to 0.67 and from 0.56 to 0.70 for the outcomes spontaneous preterm birth <37 weeks and <34 weeks of gestation, respectively. A subanalysis showed that the models discriminated poorly (AUC 0.51–0.56) for nulliparous women. Although we recalibrated the models, two models retained evidence of overfitting. The decision curve analysis showed low clinical benefit for the best performing models.

Conclusions

This review revealed several reporting and methodological shortcomings of published prediction models for spontaneous preterm birth. Our external validation study indicated that none of the models had the ability to predict spontaneous preterm birth adequately in our population. Further improvement of prediction models, using recent knowledge about both model development and potential risk factors, is necessary to provide an added value in personalized risk assessment of spontaneous preterm birth.

The effects of periodontal treatment on pregnancy outcomes

BACKGROUND

Preterm infants are at greater risk than term infants for physical and developmental disorders. Morbidity and mortality increases as gestational age at delivery decreases. Observational studies indicate an association between poor periodontal health and risk for preterm birth or low birthweight, making periodontitis a potentially modifiable risk factor for prematurity.

AIM

To identify randomized controlled trials (RCTs) published between January 2011 and July 2012 and discuss all published RCTs testing whether periodontal therapy reduces rates of preterm birth and low birthweight.

METHODS

Search of databases including PubMed, ISI Web of Science and Cochrane Library.

RESULTS

The single RCT identified showed no significant effect of periodontal treatment on birth outcomes.

DISCUSSION

All published trials included non-surgical periodontal therapy; only two included systemic antimicrobials as part of test therapy. The trials varied substantially in terms of sample size, obstetric histories of subjects, study preterm birth rates and the periodontal treatment response. The largest trials--also judged to be high-quality and at low risk of bias--have yielded consistent results, and indicate that treatment does not alter rates of adverse pregnancy outcomes.

CONCLUSION

Non-surgical periodontal therapy, scaling and root planing, does not improve birth outcomes in pregnant women with periodontitis.

The effects of periodontal treatment on pregnancy outcomes

BACKGROUND

Preterm infants are at greater risk than term infants for physical and developmental disorders. Morbidity and mortality increases as gestational age at delivery decreases. Observational studies indicate an association between poor periodontal health and risk for preterm birth or low birthweight, making periodontitis a potentially modifiable risk factor for prematurity.

AIM

To identify randomized controlled trials (RCTs) published between January 2011 and July 2012 and discuss all published RCTs testing whether periodontal therapy reduces rates of preterm birth and low birthweight.

METHODS

Search of databases including PubMed, ISI Web of Science and Cochrane Library.

RESULTS

The single RCT identified showed no significant effect of periodontal treatment on birth outcomes.

DISCUSSION

All published trials included non-surgical periodontal therapy; only two included systemic antimicrobials as part of test therapy. The trials varied substantially in terms of sample size, obstetric histories of subjects, study preterm birth rates and the periodontal treatment response. The largest trials - also judged to be high-quality and at low risk of bias - have yielded consistent results, and indicate that treatment does not alter rates of adverse pregnancy outcomes.

CONCLUSION

Non-surgical periodontal therapy, scaling and root planing, does not improve birth outcomes in pregnant women with periodontitis.

The Two-Way Association of Periodontal Infection with Systemic Disorders: An Overview

Oral cavity that harbors diverse bacterial populations could also act as a site of origin for spread of pathogenic microorganisms to different body sites, particularly in immunocompromised hosts, patients, the elderly, or the underprivileged. A number of recent publications have advocated that patients with periodontal diseases are more susceptible to metabolic endotoxemia, inflammation, obesity, type 2 diabetes, and other related systemic complications, concluding that periodontal diseases could be a potential contributing risk factor for a wide array of clinically important systemic diseases. However, despite a significant increase in the prevalence of periodontal infections and systemic diseases in the past few decades, the fundamental biological mechanisms of connection between these ailments are still not fully explicated. Consequently, the mechanisms by which this bidirectional damage occurs are being explored with a concentric vision to develop strategies that could prevent or control the complications of these ailments. This paper attempts to summarize and hypothesize the diverse mechanisms that hint to a certain connection between the two prevalent chronic situations.

Human cervicovaginal fluid biomarkers to predict term and preterm labor

Preterm birth (PTB; birth before 37 completed weeks of gestation) remains the major cause of neonatal morbidity and mortality. The current generation of biomarkers predictive of PTB have limited utility. In pregnancy, the human cervicovaginal fluid (CVF) proteome is a reflection of the local biochemical milieu and is influenced by the physical changes occurring in the vagina, cervix and adjacent overlying fetal membranes. Term and preterm labor (PTL) share common pathways of cervical ripening, myometrial activation and fetal membranes rupture leading to birth. We therefore hypothesize that CVF biomarkers predictive of labor may be similar in both the term and preterm labor setting. In this review, we summarize some of the existing published literature as well as our team's breadth of work utilizing the CVF for the discovery and validation of putative CVF biomarkers predictive of human labor. Our team established an efficient method for collecting serial CVF samples for optimal 2-dimensional gel electrophoresis resolution and analysis. We first embarked on CVF biomarker discovery for the prediction of spontaneous onset of term labor using 2D-electrophoresis and solution array multiple analyte profiling. 2D-electrophoretic analyses were subsequently performed on CVF samples associated with PTB. Several proteins have been successfully validated and demonstrate that these biomarkers are associated with term and PTL and may be predictive of both term and PTL. In addition, the measurement of these putative biomarkers was found to be robust to the influences of vaginal microflora and/or semen. The future development of a multiple biomarker bed-side test would help improve the prediction of PTB and the clinical management of patients.

The associations between bridal pregnancy and obstetric outcomes among live births in Korea: population-based study

Objective

In East Asia the recently increased number of marriages in response to pregnancy is an important social issue. This study evaluated the association of marriage preceded by pregnancy (bridal pregnancy) with obstetric outcomes among live births in Korea.

Methods

In this population-based study, 1,152,593 first singleton births were evaluated from data registered in the national birth registration database from 2004 to 2008 in Korea. In the study population, the pregnancy outcomes among live births from the bridal pregnancy group (N = 62,590) were compared with the outcomes of the post-marital pregnancy group (N = 564,749), composed of women who gave birth after 10 months but before 24 months of marriage. The variables preterm birth (PTB; <37 weeks gestation) and low birth weight (LBW; <2.5 kg) were used to determine the primary outcome. The adjusted odds ratios (aORs) and 95% confidence intervals (CIs) were calculated after controlling for socio-demographic factors.

Results

The socio-demographic factors among the bridal pregnancy group were associated with a social disadvantage and particular risk factors. In the subgroup analyses of maternal age, differences in adverse pregnancy outcomes from bridal pregnancy were identified between women in the following age group: (i) ≤19, (ii) 20–39, and (iii) ≥40 years. After the multivariate analysis, the aORs for each age group were 1.47 (95% CI: 1.15–1.89), 1.76 (1.70–1.83), and 1.13 (0.77–1.66), respectively, for PTB and 0.92 (0.70–1.21), 1.60 (1.53–1.66), and 1.11 (0.71–1.74), respectively, for LBW. In the adjusted logistic regression models, bridal pregnancy was associated with PTB (1.76, 1.69–1.82) and LBW (1.53, 1.48–1.59).

Conclusion

Pregnancy outcomes among live births from bridal pregnancies are associated with higher risks for PTB and LBW in Korea.

Whole blood gene expression profile associated with spontaneous preterm birth in women with threatened preterm labor

Threatened preterm labor (TPTL) is defined as persistent premature uterine contractions between 20 and 37 weeks of gestation and is the most common condition that requires hospitalization during pregnancy. Most of these TPTL women continue their pregnancies to term while only an estimated 5% will deliver a premature baby within ten days. The aim of this work was to study differential whole blood gene expression associated with spontaneous preterm birth (sPTB) within 48 hours of hospital admission. Peripheral blood was collected at point of hospital admission from 154 women with TPTL before any medical treatment. Microarrays were utilized to investigate differential whole blood gene expression between TPTL women who did (n = 48) or did not have a sPTB (n = 106) within 48 hours of admission. Total leukocyte and neutrophil counts were significantly higher (35% and 41% respectively) in women who had sPTB than women who did not deliver within 48 hours (p<0.001). Fetal fibronectin (fFN) test was performed on 62 women. There was no difference in the urine, vaginal and placental microbiology and histopathology reports between the two groups of women. There were 469 significant differentially expressed genes (FDR<0.05); 28 differentially expressed genes were chosen for microarray validation using qRT-PCR and 20 out of 28 genes were successfully validated (p<0.05). An optimal random forest classifier model to predict sPTB was achieved using the top nine differentially expressed genes coupled with peripheral clinical blood data (sensitivity 70.8%, specificity 75.5%). These differentially expressed genes may further elucidate the underlying mechanisms of sPTB and pave the way for future systems biology studies to predict sPTB.

Single measurement of salivary estriol as a predictor of preterm birth

One of the major problems in obstetrics and pediatrics is preterm birth. A new method of prediction of preterm birth is by salivary estriol. This study aimed to determine the predictive value of single measurement of salivary estriol and its relationship with preterm birth. In this study, the salivary specimens of 466 pregnant women of 25-34 weeks gestational age were collected and kept in a freezer until delivery. Consequently, the salivary specimens were thawed and estriol levels were measured. The cut-off point for estriol was determined by a receiver operating characteristics curve. Salivary estriol levels equal to or higher than the cut-off point (2.6 ng m(-1)) were considered as the estriol (+) group and those lower than 2.6 ng mL(-1) were considered as the estriol (-) group. Our findings showed that 36 (18.3%) subjects in the estriol (+) group and 22 (8.2%) subjects in the estriol (-) group had preterm deliveries. There was a significant relationship between salivary estriol levels and preterm birth (χ2 = 10.636, p = 0.001). Sensitivity, specificity and predictive values (positive and negative) of estriol were 62, 60, 18.3 and 82%, respectively. Single measurement of salivary estriol at 25-34 weeks of gestation, with its high negative predictive values, could be beneficial to identify women who will not develop preterm labor. This outcome suggests that unnecessary interventions should be avoided to prevent preterm births.

A Study on the Association between Low Maternal Serum Magnesium Level and Preterm Labour

Objectives. The study was aimed to assess the association between low maternal serum magnesium levels and preterm labour. Methods. It is a cross-sectional case-control study in which eligible participants were pregnant women admitted in labour within the labour ward complex of a Lagos tertiary hospital. Relevant data were extracted from the case records of these women and blood samples were obtained from all participants and serum magnesium levels measured. Results. The study showed that 36% of the study patients had varying degrees of hypomagnesaemia. The relative risk indicates that preterm labour is 1.83 times higher among the patients with low serum magnesium (less than 1.6 mg/dL). The mean difference in serum magnesium levels in both groups was statistically significant (P<0.05). Conclusion. We can infer that low serum magnesium (hypomagnesaemia) is associated with preterm onset of labour. We can, also from this finding, formulate a proposition that would help in preventing preterm labour and birth with the use of prophylactic oral magnesium supplementation among patients with higher risk for development of preterm labour.

Histological chorioamnionitis: effects on premature delivery and neonatal prognosis

BACKGROUND

Chorioamnionitis is closely related to premature birth and has negative effects on neonatal morbidity and mortality.

METHODS

In this prospective study, 43 mothers who delivered earlier than 35 gestational weeks and their 57 infants were evaluated clinically and with laboratory findings. Placentas and umbilical cords were investigated histopathologically for chorioamnionitis and funisitis.

RESULTS

The overall frequency of clinical and histological chorioamnionitis (HCA) was 8.3% and 23.2%, respectively. The frequency of HCA was 47.3% and 83.3% in mothers delivered <32 weeks and <30 weeks, respectively. Maternal demographic and clinical findings and also leukocyte and C-reactive protein values were not indicative of HCA. Infants of mothers with HCA had significantly lower Apgar scores together with higher SNAP-PE-II and CRIB scores. These infants had increased mechanical ventilator and surfactant requirements, higher incidences of patent ductus arteriosus, early sepsis, and bronchopulmonary dysplasia, and higher mortality rates. The effect of HCA on neonatal morbidity and mortality was more prominent than the effect of low birthweight and lower gestational age.

CONCLUSION

Chorioamnionitis not only causes premature deliveries, but is also associated with neonatal complications and increased mortality. Clinical findings and infectious markers in mother or infant do not predict the diagnosis of histological chorioamnionitis. Therefore, placental histopathology may have a role in predicting neonatal outcome in premature deliveries, especially those below 30 weeks.

Feeding and drinking skills in preterm and low birth weight infants compared to full term infants at a corrected age of nine months

Feeding and drinking skills were registered in 47 preterm (<32 weeks) and/or low birth weight (<1500 g) infants and compared to 52 healthy full term infants at a (corrected) age of nine months. In the preterm and/or SGA infants a delay was found for sufficient postural balance, drinking independently from a bottle, eating skills and accepting teeth brushing at a corrected age of nine months compared to healthy controls. For tongue position and movement, and choking during drinking no difference was found between both groups.

Periodontal disease and systemic complications

Periodontal diseases comprise a number of infectious and inflammatory conditions brought about by the interaction between supragingival and subgingival biofilms and the host inflammatory response. Periodontal diseases should be considered systemic conditions. This means that they are both modulated by the body's systems and play a role as a risk factor for systemic derangements. The current evidence supports some of these interactions, such as smoking as a risk factor for periodontal disease and diabetes mellitus, as both influenced by and influencing inflammatory changes in the periodontal tissue. Other potential associations are still being researched, such as obesity, hormonal changes, cardiovascular disease, and adverse outcomes in pregnancy. These, and others, still require further investigation before the repercussions of periodontal disease can be fully elucidated. Nevertheless, at the present time, the treatment of periodontal diseases-and, most importantly, their prevention-enables adequate intervention as a means of ensuring periodontal health.

Development of a prognostic model for predicting spontaneous singleton preterm birth

OBJECTIVE

To develop and validate a prognostic model for prediction of spontaneous preterm birth.

STUDY DESIGN

Prospective cohort study using data of the nationwide perinatal registry in The Netherlands. We studied 1,524,058 singleton pregnancies between 1999 and 2007. We developed a multiple logistic regression model to estimate the risk of spontaneous preterm birth based on maternal and pregnancy characteristics. We used bootstrapping techniques to internally validate our model. Discrimination (AUC), accuracy (Brier score) and calibration (calibration graphs and Hosmer-Lemeshow C-statistic) were used to assess the model's predictive performance. Our primary outcome measure was spontaneous preterm birth at <37 completed weeks.

RESULTS

Spontaneous preterm birth occurred in 57,796 (3.8%) pregnancies. The final model included 13 variables for predicting preterm birth. The predicted probabilities ranged from 0.01 to 0.71 (IQR 0.02-0.04). The model had an area under the receiver operator characteristic curve (AUC) of 0.63 (95% CI 0.63-0.63), the Brier score was 0.04 (95% CI 0.04-0.04) and the Hosmer Lemeshow C-statistic was significant (p<0.0001). The calibration graph showed overprediction at higher values of predicted probability. The positive predictive value was 26% (95% CI 20-33%) for the 0.4 probability cut-off point.

CONCLUSIONS

The model's discrimination was fair and it had modest calibration. Previous preterm birth, drug abuse and vaginal bleeding in the first half of pregnancy were the most important predictors for spontaneous preterm birth. Although not applicable in clinical practice yet, this model is a next step towards early prediction of spontaneous preterm birth that enables caregivers to start preventive therapy in women at higher risk.

Mental health in low-to-moderate risk preterm, low birth weight, and small for gestational age children at 4 to 5 years: the role of early maternal parenting

OBJECTIVES

The majority of children born preterm, with low birth weight, or small for gestational age are born with low-to-moderate risk (LTM), yet most research focuses on the high-risk group. Little is known about whether children with LTM perinatal risk are at greater risk for mental health problems, or what the role of early maternal parenting is in determining these outcomes.

METHOD

Longitudinal data were from a large nationally representative Australian cohort of 5,000 children, aged 0 to 1, 2 to 3, and 4 to 5 years of age. Participants were 354 children with LTM perinatal risk born at 33 to 36 weeks, with birth weight 1,501 to 2,499 grams, or born between the first and 10th percentiles for gestational age; and 2,461 children in the normal birth weight, term comparison group. Child mental health was measured by mother-report on the Strengths and Difficulties Questionnaire (SDQ). Parenting irritability, warmth, self-efficacy, maternal separation anxiety, and overprotective parenting were measured when children were 0 to 1 and 2 to 3 years of age.

RESULTS

Parents in the LTM perinatal risk group were more likely to experience parenting difficulties on one of eight parenting measures (irritable parenting at age 0-1 year) when adjusting for socio-demographic differences (odds ratio = 1.43; 95% confidence interval = 1.05, 1.95, p < .02). This group difference was no longer apparent by age 2 to 3 years. Compared with healthy-term peers, there were small increases in Emotional Symptoms and Total Difficulties on the SDQ for the LTM perinatal risk group at age 4 to 5 years. When accounting for maternal-specific and socio-demographic factors, LTM perinatal risk group continued to predict Emotional Symptoms but not Total Difficulties at age 4 to 5 years.

CONCLUSIONS

Children with LTM perinatal risk were at a small increased risk for emotional difficulties but did not differ significantly from other children of similar social backgrounds in their risk for generalized mental health problems. These findings support a biological and socio-economic, rather than parenting, pathway to psychological risk in children born with LTM perinatal risk.

Fetal fibronectin as a predictor of spontaneous preterm birth: a European perspective

Preterm birth (PTB) is estimated to account for 6-10% of all births worldwide with 13 million PTBs occurring annually and 1 million resulting in death. The diagnosis of spontaneous preterm labor and accurate prediction of preterm delivery is notoriously difficult. Identification of effective risk assessment markers can potentially improve outcomes by enabling targeted therapy while allowing efficient use of resources and avoiding unnecessary interventions. Advances in perinatal medicine have not reduced PTB and effective measures that improve outcome are yet to be established. However, considerable progress has been made in the development of accurate methods (fetal fibronectin and cervical length assessment) to predict PTB in both symptomatic and asymptomatic high-risk women. The excellent negative predictive value of fFN has the ability to facilitate decision-making regarding admission, in utero transfer, administration of antenatal corticosteroids and/or tocolysis and has been shown to be cost-effective. This review describes the European perspective on the use of fFN and describes ongoing European clinical studies, which are appropriately designed with meaningful endpoints, which will undoubtedly facilitate a better understanding of test accuracy and cost-effectiveness within different populations.

Periodontal diseases as an emerging potential risk factor for adverse pregnancy outcomes: A review of concepts

Preterm birth is the leading perinatal problem with subsequent morbidity and mortality in developed as well as developing nations. Among the various possible environmental, genetic, demographic, psychosocial and obstetric risk factors responsible for premature labor, poor oral health with periodontal infection has also emerged as a potential and modifiable risk factor for preterm low birth weight babies. The infected periodontium is regarded as a reservoir for periodontopathic bacteria, mainly gram negative anaerobes that serve as a source of endotoxins and lipopolysaccharides, proinflammatory cytokines and prostaglandins that enhance uterine muscle contraction leading to preterm low birth weight. Also, the progression of periodontal disease during pregnancy appears to increase the fetal growth restriction, irrespective of baseline periodontal disease status. Thus, identification and treatment of periodontal disease should be considered an important intervention strategy as a part of prenatal care to reduce adverse pregnancy outcomes.

Use of cervicovaginal fluid for the identification of biomarkers for pathologies of the female genital tract

Cervicovaginal fluid has an important function in the homeostasis and immunity of the lower female genital tract. Analysis of the cervicovaginal fluid proteome may therefore yield important information about the pathogenesis of numerous gynecological pathologies. Additionally, cervicovaginal fluid has great potential as a source of biomarkers for these conditions.

This review provides a detailed discussion about the human cervicovaginal proteome and the proteomics studies performed to characterize this biological fluid. Furthermore, infection-correlated pathological conditions of the female genital tract are discussed for which cervicovaginal fluid has been used in order to identify potential biomarkers. Recent years, numerous studies have analyzed cervicovaginal fluid samples utilizing antibody-based technologies, such as ELISA or Western blotting, to identify biomarkers for preterm birth, premature preterm rupture of membranes, bacterial vaginosis and cervical cancer. The present article will discuss the importance of proteomic technologies as alternative techniques to gain additional meaningful information about these conditions. In addition, the review focuses on recent proteomic studies on cervicovaginal fluid samples for the identification of potential biomarkers. We conclude that the use of proteomic technology for analysis of human cervicovaginal fluid samples is promising and may lead to the discovery of new biomarkers which can improve disease prevention and therapy development.

Prenatal care utilization for mothers from low-income areas of New Mexico, 1989-1999

BACKGROUND

Prenatal care is considered to be an important component of primary health care. Our study compared prenatal care utilization and rates of adverse birth outcomes for mothers from low- and higher-income areas of New Mexico between 1989 and 1999.

METHODOLOGY/PRINCIPAL FINDINGS

Prenatal care indicators included the number of prenatal care visits and the first month of prenatal care. Birth outcome indicators included low birth weight, premature birth, and births linked with death certificates. The results of our study indicated that mothers from low-income areas started their prenatal care significantly later in their pregnancies between 1989 and 1999, and had significantly fewer prenatal visits between 1989 and 1997. For the most part, there were not significant differences in birth outcome indicators between income groupings.

CONCLUSIONS/SIGNIFICANCE

These findings suggest that while mothers from low-income areas received lower levels of prenatal care, they did not experience a higher level of adverse birth outcomes.

Effect of 17-alpha hydroxyprogesterone caproate on the production of tumor necrosis factor-alpha and the expression of cyclooxygenase-2 in lipopolysaccharide-treated gravid human myometrial explants

OBJECTIVE

To determine whether 17-alpha hydroxyprogesterone (17-OHPC) alters tumor necrosis factor-alpha (TNF-alpha) production and the expression of cyclooxygenase type 2 (COX-2) in myometrium exposed to lipopolysaccharide (LPS).

STUDY DESIGN

Lower segment myometrial biopsies were obtained from non-laboring patients at term. Tissues were cultured in serum-free media with 17-OHPC (1 microM) and LPS (1 microg/ml), either alone or in combination. At 24 h, the production of tumor necrosis factor-alpha (TNF-alpha) and the expression of COX-2 was determined using enzyme linked immunosorbent assay and real-time (RT-PCR). Statistical analysis was performed using non-parametric testing. A P-value of <0.05 was considered significant.

RESULT

17-OHPC had no effect on TNF-alpha production and COX-2 expression when compared with untreated myometrial explants (P=0.61 and P=0.95). LPS induced production of TNF-alpha (P=0.03) and expression of COX-2 (P=0.02). Treatment with 17-OHPC did not block LPS-induced TNF-alpha production (P=0.37) or COX-2 expression (P=0.12).

CONCLUSION

In this pilot study, 17-OHPC did not affect the production of TNF-alpha or COX-2 expression in human myometrium.

Repeat digital cervical assessment in pregnancy for identifying women at risk of preterm labour

BACKGROUND

Repeat digital cervical assessment (RDCA - examination of the cervix with a finger) has been promoted as a routine intervention in the antenatal clinic as a screening test for the risk of preterm birth (that is, birth occurring before 37 weeks of gestation).

OBJECTIVES

To assess the effect of repeat digital cervical assessment during pregnancy for the risk of preterm birth and other adverse effects for mother and baby.

SEARCH STRATEGY

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (September 2009) and CENTRAL (The Cochrane Library 2009, Issue 3).

SELECTION CRITERIA

All known randomized clinical trials comparing repeat digital cervical assessment with internal examination limited to clinical indication or no internal examination. We have not included studies where repeat cervical assessment is only a component of complex interventions targeted at decreasing preterm birth.

DATA COLLECTION AND ANALYSIS

We evaluated relevant studies for meeting the inclusion criteria and methodological quality without considering their results. Three review authors extracted the data. For all data analyses, we entered data based on the principle of intention to treat. We calculated odds ratios and 95% confidence intervals for dichotomous data.

MAIN RESULTS

We included two trials that enrolled a total of 7163 women. Preterm birth before 37 weeks, was reported in both trials. The odds ratio for birth before 37 weeks was 1.05 (95% confidence interval 0.85 to 1.31; two trials, 6070 women). One trial (involving 5836 women) found no significant difference between the two treatment arms for the following outcomes: preterm birth before 34 weeks; preterm, prelabour rupture of membranes; hospital admission before 37 weeks; caesarean section; use of tocolytic drugs; low birthweight; very low birthweight, stillbirth, neonatal death, neonatal intensive care admissions; use of health services. The other prespecified outcomes were not evaluated in the included studies. We did not conduct the planned subgroup analyses due to insufficient data.

AUTHORS' CONCLUSIONS

We found no evidence to support the use of RDCA in pregnancy to reduce the prevalence of preterm birth. We have found insufficient evidence to assess adverse effects of the intervention.

A case-control study of preterm delivery risk factors according to clinical subtypes and severity

AIMS

To examine risk factors of preterm delivery (PTD) among Thai women.

METHODS

Our case-control study included 467 term controls and 467 PTD cases. PTD was studied in aggregate and in subgroups (i.e. spontaneous preterm labor and delivery [SPTD], preterm premature rupture of membrane [PPROM], medically indicated preterm delivery [MIPTD], moderate preterm delivery [32-36 weeks], and very preterm delivery [<32 weeks]). We used multivariable logistic regression procedures to estimate odds ratio (OR) and 95% confidence intervals (CI) of potential PTD risk factors.

RESULTS

Advanced maternal age (>or=35 years) was associated with a 2.27-fold increased PTD risk overall (95%CI: 1.40, 3.68); and with a 3.79-fold increased risk of MIPTD (95%CI: 1.89, 7.59). Young maternal age (<20 years) was associated with a 2.07-fold increased risk of SPTD (95%CI: 1.19, 3.61). Prior history of PTD was associated with a 3.64-fold increased PTD risk overall (95%CI: 1.87, 7.09), and with a 5.69-fold increased risk of MIPTD (95%CI: 2.44, 13.24). No prenatal care was associated with all PTD subtypes. Lean women (body mass index < 18.5 kg/m(2)), compared with normal weight women (18.5-24.9 kg/m(2)), had a 1.70-fold increased risk of PTD (95%CI: 1.21, 2.39). Risk of SPTD (OR = 2.16, 95%CI: 1.44, 3.24) and very PTD (OR = 2.45, 95%CI: 1.35, 4.45) were also elevated in lean women.

CONCLUSIONS

Maternal age, pre-pregnancy body mass index, prior history of PTD and no utilization of prenatal care were covariates identified in this study as risk factors for PTD. Our findings also suggest heterogeneity in risk factors for clinical subtypes of PTD.

Change in periodontitis during pregnancy and the risk of pre-term birth and low birthweight

AIM

Determine whether periodontitis progression during pregnancy is associated with adverse birth outcomes.

METHODS

We used clinical data and birth outcomes from the Obstetrics and Periodontal Therapy Study, in which randomly selected women received periodontal treatment before 21 weeks of gestation (N=413) or after delivery (410). Birth outcomes were available for 812 women and follow-up periodontal data for 722, including 75 whose pregnancies ended <37 weeks. Periodontitis progression was defined as >or=3 mm loss of clinical attachment. Birth outcomes were compared between non-progressing and progressing groups using the log rank and t tests, separately in all women and in untreated controls.

RESULTS

The distribution of gestational age at the end of pregnancy (p>0.1) and mean birthweight (3295 versus 3184 g, p=0.11) did not differ significantly between women with and without disease progression. Gestational age and birthweight were not associated with change from baseline in percentage of tooth sites with bleeding on probing or between those who did versus did not progress according to a published definition of disease progression (p>0.05).

CONCLUSIONS

In these women with periodontitis and within this study's limitations, disease progression was not associated with an increased risk for delivering a pre-term or a low birthweight infant.

Demographic, clinical and occupational characteristics associated with early onset of delivery: findings from the Duke Health and Safety Surveillance System, 2001-2004

BACKGROUND

This cross-sectional study explores associations between preterm delivery and demographic, clinical and occupational characteristics of women employed within a university and health system.

METHODS

A comprehensive surveillance system linking individual-level data from Human Resources, medical insurance claims and a job-exposure matrix was used to identify women with a single live birth between 2001 and 2004 and describe maternal characteristics during pregnancy.

RESULTS

Preterm delivery occurred in 7.1% (n = 74) of the 1,040 women, a lower preterm delivery prevalence than observed in the general U.S. population. Nearly all (>99.5%) women utilized prenatal care services. Prevalence of preterm delivery was highest for inpatient nurses, nurses' aides and office staff. In multivariate analyses, preterm delivery was positively associated with several clinical conditions: placenta previa, diabetes and cardiovascular disorder/disease.

CONCLUSIONS

We observed associations between preterm delivery and several previously indicated clinical conditions. Further study of the effect of job characteristics on preterm delivery is warranted.

Evaluation of preterm births and birth defects in liveborn infants of US military women who received smallpox vaccine

BACKGROUND

Women serving in the US military have some unique occupational exposures, including exposure to vaccinations that are rarely required in civilian professions. When vaccinations are inadvertently given during pregnancy, such exposures raise special concerns. These analyses address health outcomes, particularly preterm births and birth defects, among infants who appear to have been exposed to maternal smallpox vaccination in pregnancy.

METHODS

This retrospective cohort study included 31,420 infants born to active-duty military women during 2003-2004. We used Department of Defense databases to define maternal vaccination and infant health outcomes. Multivariable regression models were developed to describe associations between maternal smallpox vaccination and preterm births and birth defects in liveborn infants.

RESULTS

There were 7,735 infants identified as born to women ever vaccinated against smallpox, and 672 infants born to women vaccinated in the first trimester of pregnancy. In multivariable modeling, maternal smallpox vaccination in pregnancy was not associated with preterm or extreme preterm delivery. Maternal smallpox vaccination in the first trimester of pregnancy was not significantly associated with overall birth defects (OR 1.40; 95% CI: 0.94, 2.07), or any of seven specific defects individually modeled.

CONCLUSIONS

Results may be reassuring that smallpox vaccine, when inadvertently administered to pregnant women, is not associated with preterm delivery or birth defects in liveborn infants.

Non-invasive prenatal diagnosis: implications for antenatal diagnosis and management of high-risk pregnancies

There has been a huge effort in the last 2-3 decades to develop non-invasive prenatal diagnosis to avoid the risks to the fetus caused by invasive procedures. Obtaining fetal nucleic material for molecular analysis without the need of invasive procedures has been a goal of prenatal diagnosis for many years; this is now been made possible by the use of non-cellular fetal nucleic acids circulating in maternal blood. The placenta is the primary source of these nucleic acids, raising the possibility that they could be a marker for pregnancy complications resulting from placental disease/dysfunction such as pre-eclampsia and fetal growth restriction. If so, these markers might be able to identify cases at risk, predict disease and/or its severity or allow early diagnosis. This has the potential to allow improvements in the management of complicated pregnancies.