Low saliva progesterone concentrations are associated with spontaneous early preterm labour (before 34 weeks of gestation) in women at increased risk of preterm delivery

Biomarkers for Preterm Delivery

Preterm birth occurring before the thirty-seventh gestational week complicates 4.5%-18% of pregnancies worldwide. The pathogenesis of spontaneous preterm delivery is not fully understood. Among the factors held to be responsible for its pathogenesis, the most emphasized is the inflammatory process. Studies in terms of the prediction of preterm delivery are basically divided into 3 categories: 1) Prediction in pregnant women who are asymptomatic and without risk factors, 2) Prediction in pregnant women who are asymptomatic and have risk factors, 3) Prediction in symptomatic pregnant women who have threatened preterm labour. In this chapter, the topic of biomarkers in relation to preterm delivery is discussed. The most commonly used markers in published studies are fetal fibronectin, cervical pIGFBP-1 and cervical length measurement by transvaginal ultrasound. For prediction in symptomatic pregnant women applying to the hospital with threatened preterm labour, the markers used are fetal fibronection, insulin-like growth factors (IGFs) and inflammatory markers. Preterm labour prediction with markers checked in the first and second trimesters are fetal fibronection, insulin-like growth factors (IGFs), micro RNAs, progesterone, circulating microparticles (CMPs), inflammatory markers, matrix metalloproteinases, aneuploidy syndrome screening test parameters and other hormones.

Reproducibility of saliva progesterone measured by immunoassay compared to liquid chromatography mass spectrometry

Immunoassay overestimates progesterone in blood, but no studies have tested whether this occurs in saliva. We measured progesterone in saliva using immunoassay and mass spectrometry. We tested the immunoassay for cross reactivity with dehydroepiandrosterone sulfate (DHEA-S) and 17α-hydroxyprogesterone (17α-OHP). Progesterone was significantly higher in immunoassay compared to mass spectrometry. Immunoassay progesterone levels increased in when incremental levels of 17α-OHP standard was added. This effect was not observed with the addition of DHEA-S. Research using salivary progesterone immunoassay techniques should be wary, particularly with individuals taking steroid supplementation or with high levels of progesterone metabolites.

Testing an infection model to explain excess risk of preterm birth with long-term iron supplementation in a malaria endemic area

Background

In view of recent evidence from a randomized trial in Burkina Faso that periconceptional iron supplementation substantially increases risk of spontaneous preterm birth (< 37 weeks) in first pregnancies (adjusted relative risk = 2.22; 95% CI 1.39–3.61), explanation is required to understand potential mechanisms, including progesterone mediated responses, linking long-term iron supplementation, malaria and gestational age.

Methods

The analysis developed a model based on a dual hit inflammatory mechanism arising from simultaneous malaria and gut infections, supported in part by published trial results. This model is developed to understand mechanisms linking iron supplementation, malaria and gestational age. Background literature substantiates synergistic inflammatory effects of these infections where trial data is unavailable. A path modelling exercise assessed direct and indirect paths influencing preterm birth and gestation length.

Results

A dual hit hypothesis incorporates two main pathways for pro-inflammatory mechanisms, which in this model, interact to increase hepcidin expression. Trial data showed preterm birth was positively associated with C-reactive protein (P = 0.0038) an inflammatory biomarker. The malaria pathway upregulates C-reactive protein and serum hepcidin, thereby reducing iron absorption. The enteric pathway results from unabsorbed gut iron, which induces microbiome changes and pathogenic gut infections, initiating pro-inflammatory events with lipopolysaccharide expression. Data from the trial suggest that raised hepcidin concentration is a mediating catalyst, being inversely associated with shorter gestational age at delivery (P = 0.002) and positively with preterm incidence (P = 0.007). A segmented regression model identified a change-point consisting of two segments before and after a sharp rise in hepcidin concentration. This showed a post change hepcidin elevation in women with increasing C-reactive protein values in late gestation (post-change slope 0.55. 95% CI 0.39–0.92, P < 0.001). Path modelling confirmed seasonal malaria effects on preterm birth, with mediation through C-reactive protein and (non-linear) hepcidin induction.

Conclusions

Following long-term iron supplementation, dual inflammatory pathways that mediate hepcidin expression and culminate in progesterone withdrawal may account for the reduction in gestational age observed in first pregnancies in this area of high malaria exposure. If correct, this model strongly suggests that in such areas, effective infection control is required prior to iron supplementation to avoid increasing preterm births.

Trial registration NCT01210040. Registered with Clinicaltrials.gov on 27th September 2010

Rationale & design of the PROMISES study: a prospective assessment and validation study of salivary progesterone as a test for preterm birth in pregnant women from rural India

Background

In India, 3.6 million pregnancies are affected by preterm birth annually, with many infants dying or surviving with disability. Currently, there is no simple test available for screening all women at risk of spontaneous PTB in low income setting, although high resource settings routinely use cervical length measurement and cervico-vaginal fluid fetal fibronectin for identification and care of women at risk due to clinical history. In rural India, where the public health system has limited infrastructure, trained staff and equipment, there is a greater need to develop a low-cost screening approach for providing early referral, treatment and remedial support for pregnant women at risk of preterm birth. There is interest in the use of a salivary progesterone test as a screening tool preliminary evidence from India, Egypt and UK has shown promise for this type of test. The test requires further validation in a low resource community setting.

Methods

The Promises study aims to validate and test the feasibility of introducing a low-cost salivary progesterone preterm birth prediction test in two rural districts in India with high rates of prematurity. It is a prospective study of 2000 pregnant women recruited from Panna and Satna in Madhya Pradesh over approximately 24 months. Demographic and pregnancy outcome data will be collected, and pregnancies will be dated by ultrasound sonography. Saliva progesterone will be measured by ELISA in samples obtained between 24–28 weeks of gestation. The association between salivary progesterone and preterm birth will be determined and the utility of salivary progesterone to predict preterm birth < 34, as well as < 30 and < 37 weeks assessed. Additional qualitative data will be obtained in terms of acceptability and feasibility of saliva progesterone testing and knowledge of PTB.

Discussion

A validated cost-effective saliva test, which has potential for further adaptation to a ‘point of care’ setting will allow early identification of pregnant women at risk of preterm birth, who can be linked to an effective pathway of care and support to reduce preterm birth and associated adverse consequences. This will reduce both economic and emotional burden on the affected women and their families.

Plasma progesterone, estradiol, and unconjugated estriol concentrations in twin pregnancies: Relation with cervical length and preterm delivery

INTRODUCTION

The aim of this study was to examine the association between plasma hormone concentrations, cervical length, and preterm delivery in twin pregnancies, including the effect of progesterone treatment.

MATERIAL AND METHODS

This study included 191 women pregnant with twins from a randomized placebo-controlled trial. A baseline blood sample was collected at 18-24 weeks before treatment with vaginal progesterone (n = 95) or placebo pessaries (n = 96), and 167 (87.4%) women had a second sample collected after 4-8 weeks of treatment. At baseline, 155 (81.2%) women had their cervical length measured. Progesterone, estradiol, and unconjugated estriol concentration was measured, and the association between hormone concentrations, cervical length, and gestational age at delivery was examined. Hormone concentrations were compared in the placebo and progesterone group. Statistical analysis included Spearman's rho, Mann-Whitney U test, Cuzick's test for trends, and linear regression analyses.

RESULTS

A short cervical length was associated with preterm delivery. Cervical length and hormone concentrations were not associated (Spearman's rho; progesterone -.05, estradiol .04, estriol .08). Decreasing gestational age at delivery was associated with higher progesterone and estradiol concentrations at baseline (P trend; progesterone 0.04, estradiol 0.02) but not in the second sample or in the weekly change between samples. Progesterone treatment did not increase the progesterone concentration.

CONCLUSIONS

Plasma concentrations of progesterone, estradiol, and unconjugated estriol at 18-24 weeks are not associated with cervical length or preterm delivery in twin pregnancies. Vaginal progesterone treatment does not increase the circulating progesterone concentration in twin pregnancies. Cervical length, but not hormone concentration, is predictive of preterm delivery in twin gestations.

Prediction of spontaneous preterm birth: salivary progesterone assay and transvaginal cervical length assessment after 24 weeks of gestation, another critical window of opportunity

Objectives: Measurement of salivary progesterone (SP4) levels and cervical length (CL) after 24 weeks to assess their potential predictive value among asymptomatic women at high risk of spontaneous preterm birth (PTB). Methods: This prospective observational (noninterventional) study consecutively recruited asymptomatic women at high risk of spontaneous PTB. SP4 and CL were measured at recruitment (24-28 weeks of gestation) then repeated after 3-4 weeks. All recruited women were followed up regularly till delivery. The primary outcome measure was the occurrence of spontaneous PTB. Results: One hundred and thirty four women completed the study, 22 (16.4%) and 32 (23.9%) women had early (<34 weeks) and late (≥34 weeks) PTB, respectively. Initially, the mean CL was 3.2 ± 0.6 cm and the mean SP4 was 4062.8 ± 814.6 pg/ml; with follow up, the mean CL became 3.0 ± 0.6 cm and the mean SP4 became 3871.6 ± 1136.9. Women with early PTB had significantly lower initial and follow up CL and SP4 measures when compared to women with late PTB and those who had birth at term. The rate of drop in SP4 and CL measurements between the two visits was also significantly higher among women with early PTB than those with late PTB and term birth. Receiver-operating characteristic (ROC) curves showed that, CL was a good predictor but SP4 was a better predictor of PTB as the area under the curve (AUC) for CL was less than that for SP4 at both visits (i.e. 0.858 and 0.868 versus 0.986 and 0.990 at the initial and follow up visits, respectively). There was a statistically significant correlation between CL and SP4 measurements. Multivariable binary logistic regression analysis revealed that follow up SP4 measurement was the only independent predictor of spontaneous PTB, and neither BMI, maternal age, SP4 nor CL were independent predictors of early spontaneous PTB. Conclusions: After 24 gestational weeks, SP4 assessment is a simple and reliable promising tool to predict spontaneous PTB among asymptomatic high-risk women, with a little superior performance than CL measurement.

Hospital admission for hyperemesis gravidarum in women at increased risk of spontaneous preterm birth

BACKGROUND

Progesterone administration prevents spontaneous preterm birth (sPTB) in women at increased risk. Progesterone concentration is lower in women with subsequent sPTB. Conversely, high concentrations of progesterone are implicated in the pathogenesis of hyperemesis gravidarum (HG). We hypothesized that women at increased risk of sPTB or spontaneous late miscarriage would be less likely to have a diagnosis of HG. To explore this hypothesis, we compared the incidence of HG in women at increased risk of sPTB and women with no identifiable risk factors.

METHODS

Women at increased risk of sPTB were identified from a specialist Preterm Birth Clinic (PTBC) database where criteria for PTBC attendance are previous cervical surgery, previous sPTB <34 weeks, previous spontaneous late miscarriage, incidental sonographic cervical shortening, and uterine anomaly. Hospital antenatal booking and coding records for the same time period were examined to identify HG admissions. Women with multiple gestations, trophoblastic disease, or pre-existing abnormal thyroid function were excluded. The incidence of HG among PTBC (n=394) and non-PTBC attendees (n=4762) was calculated.

RESULTS

The incidence of HG was lower in women at increased risk of sPTB (1.52%, n=6) compared with women with no identifiable risk factor for sPTB (3.33%, n=159; P=.049).

CONCLUSION

Hospital admission for HG is reduced in women with risk factors for sPTB compared with those without risk factors. Exploration of the pathogenesis of HG may improve understanding of the mechanisms underlying sPTB.

Bitter taste receptors as targets for tocolytics in preterm labor therapy

Preterm birth (PTB) is the leading cause of neonatal mortality and morbidity, with few prevention and treatment options. Uterine contraction is a central feature of PTB, so gaining new insights into the mechanisms of this contraction and consequently identifying novel targets for tocolytics are essential for more successful management of PTB. Here we report that myometrial cells from human and mouse express bitter taste receptors (TAS2Rs) and their canonical signaling components (i.e., G-protein gustducin and phospholipase C β2). Bitter tastants can completely relax myometrium precontracted by different uterotonics. In isolated single mouse myometrial cells, a phenotypical bitter tastant (chloroquine, ChQ) reverses the rise in intracellular Ca2+ concentration ([Ca2+]i) and cell shortening induced by uterotonics, and this reversal effect is inhibited by pertussis toxin and by genetic deletion of α-gustducin. In human myometrial cells, knockdown of TAS2R14 but not TAS2R10 inhibits ChQ's reversal effect on an oxytocin-induced rise in [Ca2+]i Finally, ChQ prevents mouse PTBs induced by bacterial endotoxin LPS or progesterone receptor antagonist mifepristone more often than current commonly used tocolytics, and this prevention is largely lost in α-gustducin-knockout mice. Collectively, our results reveal that activation of the canonical TAS2R signaling system in myometrial cells produces profound relaxation of myometrium precontracted by a broad spectrum of contractile agonists, and that targeting TAS2Rs is an attractive approach to developing effective tocolytics for PTB management.-Zheng, K., Lu, P., Delpapa, E., Bellve, K., Deng, R., Condon, J. C., Fogarty, K., Lifshitz, L. M., Simas, T. A. M., Shi, F., ZhuGe, R. Bitter taste receptors as targets for tocolytics in preterm labor therapy.

Placental hormone profiles as predictors of preterm birth in twin pregnancy: A prospective cohort study

Objective

The objective of the study was to analyse placental hormone profiles in twin pregnancies to determine if they could be used to predict preterm birth.

Study design

Progesterone, estradiol, estriol and corticotropin-releasing hormone were measured using competitive immunoassay and radioimmunoassay in serum and saliva samples of 98 women with twin pregnancies,at 3 or more gestational timepoints. Hormone profiles throughout gestation were compared between very preterm (<34 weeks; n = 8), preterm (<37 weeks; n = 40) and term (37+ weeks; n = 50) deliveries.

Results

No significant differences were found between preterm and term deliveries in either absolute hormone concentrations or ratios. Estimated hormone concentrations and ratios at 26 weeks did not appear to predict preterm delivery. Salivary and serum hormone concentrations were generally poorly correlated.

Conclusion

Our results suggest that serial progesterone, estradiol, estriol and corticotropin-releasing hormone measurements in saliva and serum are not robust biomarkers for preterm birth in twin pregnancies.

Phenols and parabens in relation to reproductive and thyroid hormones in pregnant women

INTRODUCTION

Phenols and parabens are ubiquitous environmental contaminants. Evidence from animal studies and limited human data suggest they may be endocrine disruptors. In the current study, we examined associations of phenols and parabens with reproductive and thyroid hormones in 106 pregnant women recruited for the prospective cohort, "Puerto Rico Testsite for Exploring Contamination Threats (PROTECT)".

METHODS

Urinary exposure biomarkers (bisphenol A, triclosan, benzophenone-3, 2,4-dichlorophenol, 2,5-dichlorophenol, butyl, methyl and propyl paraben) and serum hormone levels (estradiol, progesterone, sex hormone-binding globulin (SHBG), free triiodothyronine (FT3), free thyroxine (FT4) and thyroid stimulating hormone) were measured at up to two time points during pregnancy (16-20 weeks and 24-28 weeks). We used linear mixed models to assess relationships between exposure biomarkers and hormone levels across pregnancy, controlling for urinary specific gravity, maternal age, BMI and education. In sensitivity analyses, we evaluated cross-sectional relationships between exposure and hormone levels stratified by study visit using linear regression.

RESULTS

An IQR increase in methyl paraben was associated with a 7.70% increase (95% CI 1.50, 13.90) in SHBG. Furthermore, an IQR increase in butyl paraben as associated with an 8.46% decrease (95% CI 16.92, 0.00) in estradiol, as well as a 9.34% decrease (95% CI -18.31,-0.38) in estradiol/progesterone. Conversely, an IQR increase in butyl paraben was associated with a 5.64% increase (95% CI 1.26, 10.02) in FT4. Progesterone was consistently negatively associated with phenols, but none reached statistical significance. After stratification, methyl and propyl paraben were suggestively negatively associated with estradiol at the first time point (16-20 weeks), and suggestively positively associated with estradiol at the second time point (24-28 weeks).

CONCLUSIONS

Within this ongoing birth cohort, certain phenols and parabens were associated with altered reproductive and thyroid hormone levels during pregnancy. These changes may contribute to adverse health effects in mothers or their offspring, but additional research is required.

Progesterone supplementation for HIV-positive pregnant women on protease inhibitor-based antiretroviral regimens (the ProSPAR study): a study protocol for a pilot randomized controlled trial

Background

In Canada, the majority of HIV-positive pregnant women receive combination antiretroviral therapy that includes a ritonavir-boosted protease inhibitor to prevent mother-to-child HIV transmission. However, protease inhibitor-based combination antiretroviral therapy has been associated with increased rates of preterm, low birth weight, and small for gestational age births. Our previous experimental findings demonstrate that protease inhibitor use during pregnancy is associated with decreased progesterone levels that correlate with fetal growth, and that progesterone supplementation can improve protease inhibitor-induced fetal growth restriction. We hypothesize that HIV-positive pregnant women who receive protease inhibitor-based combination therapy may also benefit from progesterone supplementation during pregnancy.

Methods/design

In order to test this hypothesis, we have designed an open-label, multi-centre, randomized controlled (parallel group) pilot trial. The initial goal of this trial is to test feasibility and acceptability of our intervention. Forty HIV-positive pregnant women who are either on, or intending to start or switch to a boosted protease inhibitor-based combination antiretroviral regimen will be enrolled from six sites across Ontario, Canada. Twenty-five women will be randomized to self-administer natural progesterone (Prometrium, 200 mg) vaginally every night starting between gestational week 16 and 24 until week 36, and 15 women will be randomized to no intervention. While the participants and treating physicians will not be blinded, the laboratory personnel performing the biochemical and morphological evaluations will be blinded to ensure unbiased evaluation. The primary outcome of the pilot study is the feasibility of enrolment as measured by the recruitment rate and patient-reported reasons to decline participation. Secondary outcomes in participants include safety, acceptability, and adherence to progesterone supplementation.

Discussion

Given the safety of intravaginal progesterone and its current use in the general obstetrical population to prevent recurrent preterm delivery, this pilot study will provide data to determine the feasibility of a larger randomized controlled trial to assess the impact of this intervention on improving neonatal health in the context of HIV-positive pregnancies.

Trial registration

ClinicalTrials.gov, NCT02400021

Low Prolactin and High 20-α-Hydroxysteroid Dehydrogenase Levels Contribute to Lower Progesterone Levels in HIV-Infected Pregnant Women Exposed to Protease Inhibitor-Based Combination Antiretroviral Therapy

BACKGROUND

It has been reported that pregnant women receiving protease inhibitor (PI)-based combination antiretroviral therapy (cART) have lower levels of progesterone, which put them at risk of adverse birth outcomes, such as low birth weight. We sought to understand the mechanisms involved in this decline in progesterone level.

METHODS

We assessed plasma levels of progesterone, prolactin, and lipids and placental expression of genes involved in progesterone metabolism in 42 human immunodeficiency virus (HIV)-infected and 31 HIV-uninfected pregnant women. In vitro studies and a mouse pregnancy model were used to delineate the effect of HIV from that of PI-based cART on progesterone metabolism.

RESULTS

HIV-infected pregnant women receiving PI-based cART showed a reduction in plasma progesterone levels (P= .026) and an elevation in placental expression of the progesterone inactivating enzyme 20-α-hydroxysteroid dehydrogenase (20α-HSD; median, 2.5 arbitrary units [AU]; interquartile range [IQR], 1.00-4.10 AU), compared with controls (median, 0.89 AU; IQR, 0.66-1.26 AU;P= .002). Prolactin, a key regulator of 20α-HSD, was lower (P= .012) in HIV-infected pregnant women. We observed similar data in pregnant mice exposed to PI-based cART. In vitro inhibition of 20α-HSD activity in trophoblast cells reversed PI-based cART-induced decreases in progesterone levels.

CONCLUSIONS

Our data suggest that the decrease in progesterone levels observed in HIV-infected pregnant women exposed to PI-based cART is caused, at least in part, by an increase in placental expression of 20α-HSD, which may be due to lower prolactin levels observed in these women.

Is renal hyperfiltration protective in chronic kidney disease-stage 1 pregnancies? A step forward unravelling the mystery of the effect of stage 1 chronic kidney disease on pregnancy outcomes

BACKGROUND

The correlation between advanced or proteinuric chronic kidney disease (CKD) and adverse pregnancy outcomes is intuitive, although how early CKD affects pregnancy remains unknown. Glomerular hyperfiltration is a physiological response to pregnancy, correlated with outcomes in hypertension or collagen diseases. The aim of the study was to correlate first trimester hyperfiltration with pregnancy outcomes in stage 1 CKD patients.

METHODS

A historical prospective study was conducted on the database of our Unit, gathering all pregnant CKD patients referred since 1 January 2000. From 383 pregnancies referred in 2000-2013, 75 patients were selected (stage 1 CKD, referred within the 14th gestational week, singleton deliveries, absence of diabetes, hypertension or nephrotic proteinuria at referral, body mass index [BMI] < 30); 267 'low-risk' pregnancies, followed in the same setting, served as controls. Glomerular filtration rate (GFR) was assessed by Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) and dichotomized at 120 mL/min. The odds for Caesarean section, prematurity, need for Neonatal Intensive Care Unit (NICU) were assessed by univariate analysis and logistic regression.

RESULTS

Risk for adverse pregnancy outcomes was not affected by hyperfiltration (univariate OR GFR ≥ 120 mL/min: Caesarean section 1.30 (0.46-3.65); preterm delivery: 0.84 (0.25-2.80)). In contrast, even in these cases with normal kidney function, stage 1 CKD was associated with prematurity (17.3% vs 4.9% P = 0.001), lower birth weight (3027 ± 586 versus 3268 ± 500 P < 0.001) need for NICU (12% vs 1.1% P < 0.001). In the multivariate analysis, the risks were significantly increased by proteinuria and maternal age but not by GFR.

CONCLUSIONS

In pregnant Stage 1 CKD patients, hyperfiltration was not associated with maternal-foetal outcomes, thus suggesting a need to focus attention on qualitative factors, eventually enhanced by age, as vascular stiffness, endothelial damage or oxidative stress.

Prenatal lignan exposures, pregnancy urine estrogen profiles and birth outcomes

During pregnancy, human exposure to endogenous estrogens and xenoestrogens (such as lignans) may comprehensively impact the gestational maintenance and fetal growth. We measured the concentrations of 5 lignans and the profile of 13 estrogen metabolites (EMs) in the urine samples of 328 pregnant women and examined their associations with birth outcomes. We found significantly positive associations between gestational age and urinary matairesinol (MAT), enterodiol (END) and enterolactone (ENL), as well as 16-hydroxylation pathway EMs. There were consistently positive relationships between END and the 16-hydroxylation pathway EMs. The positive relationships of MAT, END and ENL exposures with the length of gestation were mainly in the low exposure strata of the levels of these EMs. This study reveals that MAT, END and ENL as well as 16-hydroxylation pathway EMs are associated with birth outcomes, and that there are interactive relationships between lignans and 16-hydroxylation pathway EMs with birth outcomes.

Predicting Preterm Labour: Current Status and Future Prospects

Preterm labour and birth are a major cause of perinatal morbidity and mortality. Despite modern advances in obstetric and neonatal management, the rate of preterm birth in the developed world is increasing. Yet even though numerous risk factors associated with preterm birth have been identified, the ability to accurately predict when labour will occur remains elusive, whether it is at a term or preterm gestation. In the latter case, this is likely due to the multifactorial aetiology of preterm labour wherein women may display different clinical presentations that lead to preterm birth. The discovery of novel biomarkers that could reliably identify women who will subsequently deliver preterm may allow for timely medical intervention and targeted therapeutic treatments aimed at improving maternal and fetal outcomes. Various body fluids including amniotic fluid, urine, saliva, blood (serum/plasma), and cervicovaginal fluid all provide a rich protein source of putative biochemical markers that may be causative or reflective of the various pathophysiological disorders of pregnancy, including preterm labour. This short review will highlight recent advances in the field of biomarker discovery and the utility of single and multiple biomarkers for the prediction of preterm birth in the absence of intra-amniotic infection.

Salivary progesterone and cervical length measurement as predictors of spontaneous preterm birth

OBJECTIVE

To evaluate the efficacy of salivary progesterone, cervical length measurement in predicting preterm birth (PTB).

METHODS

Prospective observational study included 240 pregnant women with gestational age (GA) 26-34 weeks classified into two equal groups; group one are high risk for PTB (those with symptoms of uterine contractions or history of one or more spontaneous preterm delivery or second trimester abortion) and group 2 are controls.

RESULTS

There was a highly significant difference between the two study groups regarding GA at delivery (31.3 ± 3.75 in high risk versus 38.5 ± 1.3 in control), cervical length measured by transvaginal ultrasound (24.7 ± 8.6 in high risk versus 40.1 ± 4.67 in control) and salivary progesterone level (728.9 ± 222.3 in high risk versus 1099.9 ± 189.4 in control; p < 0.001). There was a statistically significant difference between levels of salivary progesterone at different GA among the high risk group (p value 0.035) but not in low risk group (p value 0.492). CL measurement showed a sensitivity of 71.5% with 100% specificity, 100% PPV, 69.97% NPV and accuracy of 83%, while salivary progesterone showed a sensitivity of 84% with 90% specificity, 89.8% PPV, 85.9% NPV and accuracy of 92.2%.

CONCLUSION

The measurement of both salivary progesterone and cervical length are good predictors for development of PTB.

Combinatory approaches prevent preterm birth profoundly exacerbated by gene-environment interactions

There are currently more than 15 million preterm births each year. We propose that gene-environment interaction is a major contributor to preterm birth. To address this experimentally, we generated a mouse model with uterine deletion of Trp53, which exhibits approximately 50% incidence of spontaneous preterm birth due to premature decidual senescence with increased mTORC1 activity and COX2 signaling. Here we provide evidence that this predisposition provoked preterm birth in 100% of females exposed to a mild inflammatory insult with LPS, revealing the high significance of gene-environment interactions in preterm birth. More intriguingly, preterm birth was rescued in LPS-treated Trp53-deficient mice when they were treated with a combination of rapamycin (mTORC1 inhibitor) and progesterone (P4), without adverse effects on maternal or fetal health. These results provide evidence for the cooperative contributions of two sites of action (decidua and ovary) toward preterm birth. Moreover, a similar signature of decidual senescence with increased mTORC1 and COX2 signaling was observed in women undergoing preterm birth. Collectively, our findings show that superimposition of inflammation on genetic predisposition results in high incidence of preterm birth and suggest that combined treatment with low doses of rapamycin and P4 may help reduce the incidence of preterm birth in high-risk women.

Maternal stress/distress, hormonal pathways and spontaneous preterm birth

BACKGROUND

Although second-trimester blood corticotrophin-releasing hormone (CRH) levels are robustly associated with preterm birth, the findings with respect to cortisol have been inconsistent, as have been those relating stress hormones to measured stressors and maternal distress.

METHODS

We measured plasma CRH, adrenocorticotrophic hormone (ACTH), cortisol, cortisol-binding globulin, oestradiol and progesterone at 24-26 weeks in a nested case-control study of 206 women who experienced spontaneous preterm birth and 442 term controls. We also related the hormonal levels to measures of environmental stressors, perceived stress and maternal distress (also assessed at 24-26 weeks) and to placental histopathology.

RESULTS

With the exception of an unexpectedly low oestradiol:progesterone ratio among cases (adjusted odds ratio = 0.5 [95% confidence interval 0.3, 0.8] for ratios above the median in controls), none of the hormonal measures was independently associated with spontaneous preterm birth; placental histopathological evidence of infection/inflammation, infarction or decidual vasculopathy; or measures of maternal stress or distress. CRH levels were positively associated with cortisol, but not with ACTH, whereas ACTH was also positively associated with cortisol.

CONCLUSIONS

Our findings suggest an intact pituitary-adrenal axis and confirm the positive feedback effect of cortisol on (placental) CRH. Neither of these hormonal pathways, however, was strongly linked to maternal stress/distress or to the risk of spontaneous preterm birth.

Salivary progesterone as a biochemical marker to predict early preterm birth in asymptomatic high-risk women

OBJECTIVE

To evaluate salivary progesterone as a predictor of early preterm birth (PTB) and compare it with transvaginal sonographic (TVS) cervical length in asymptomatic high-risk women.

DESIGN

Prospective study.

SETTING

Departments of Obstetrics and Gynaecology and Biochemistry at UCMS & GTBH, Delhi, India.

SAMPLE

Ninety pregnant women.

METHODS

The progesterone concentration in saliva of asymptomatic pregnant women at high risk for preterm delivery was estimated by immunoassay, and cervical length was measured by TVS, at the first antenatal visit at 24-28 weeks of gestation, and then repeated 3-4 weeks later.

MAIN OUTCOME MEASURES

Early PTB, mean and critical cut-off values of salivary progesterone, and a diagnostic value comparison of salivary progesterone with TVS cervical length.

RESULTS

The mean value of salivary progesterone was significantly lower in all women who delivered at <37 weeks of gestation (n = 38), compared with the term group (n = 52; P < 0.001). Salivary progesterone decreased significantly from the first to the second visit, with the maximum decrease observed in women who delivered at <34 weeks of gestation (29.6%, 95% CI 17.8-41.4%, P < 0.002). The single predictive critical cut-off value for salivary progesterone was 2575 pg/ml, below which more than 80% of women delivered prematurely before 34 weeks of gestation, with sensitivity, specificity, and positive and negative predictive values of 83% (95% CI 58.6-96.4%), 86% (95% CI 75.9-93.1%), 60% (95% CI 38.6-78.8%) and 95% (95% CI 87.1-99.0%), respectively. The TVS cervical length decreased significantly (P < 0.001) in the women who delivered prematurely.

CONCLUSIONS

Low salivary progesterone concentration can be used for predicting early PTB in asymptomatic high-risk women.

Salivary concentration of progesterone and cortisol significantly differs across individuals after correcting for blood hormone values

Between-individual variation of salivary progesterone (P4) and cortisol levels does not always closely reflect blood hormone concentrations. This may be partly a function of individual differences in salivary hormone excretion. We tested whether time of day at sampling and ethnicity contributed to individual variation in salivary hormones after adjusting for blood hormone levels. Forty-three Caucasian and 15 Japanese women (18-34 years) collected four sets of matched dried blood spot (DBS) and saliva specimens across a menstrual cycle (N = 232 specimen sets). Linear fixed-effects (LFE) models were used to estimate the effects of diurnal variation and ethnicity on salivary P4 and cortisol while adjusting for DBS levels. For each hormone, women with exclusively positive or negative residuals (unexplained variance) from the LFE models were categorized as high- or low-saliva-to-DBS hormone ratio (SDR; high or low salivary secretors), respectively. We found that salivary P4 (P < 0.05) was significantly higher in early morning compared to the afternoon, after controlling for DBS levels, ethnicity, and BMI. After further adjusting for this diurnal effect, significant individual variation in salivary P4 and cortisol remained: sixteen and nine women, respectively were categorized as low or high salivary secretors for both hormones (P < 0.001), suggesting systematic individual-specific variation of salivary hormonal concentration. We conclude that when saliva is used to quantify P4 or cortisol levels, time of day at sampling should be controlled. Even with this adjustment, salivary P4 and cortisol do not closely mirror between- individual variation of serum P4 and cortisol in a substantial proportion of individuals.

Pregnancy in CKD: whom should we follow and why?

BACKGROUND

Chronic kidney disease (CKD) has a high prevalence in pregnancy. In a period of cost constraints, there is the need for identification of the risk pattern and for follow-up.

METHODS

Patients were staged according to K-DOQI guidelines. The analysis was prospective, January 2000-June 2011. Two hundred and forty-nine pregnancies were observed in 225 CKD patients; 176 singleton deliveries were recorded. The largest group encompasses stage 1 CKD patients, with normal renal function, in which 127 singleton deliveries were recorded. No hard outcomes occurred (death; dialysis); therefore, surrogate outcomes were analysed [caesarean section, prematurity, need for neonatal intensive care unit (NICU)]. Stage 1 patients were compared with normal controls (267 low-risk pregnancies followed in the same setting) and with patients with CKD stages 2-4 (49 singleton deliveries); two referral patterns were also analysed (known diagnoses; new diagnoses).

RESULTS

The risk for adverse pregnancy rises significantly in stage 1 CKD, when compared with controls: odds ratios were caesarean section 2.73 (1.72-4.33); preterm delivery 8.50 (4.11-17.57); NICU 16.10 (4.42-58.66). The risks rise in later stages. There is a high prevalence of new CKD diagnosis (overall: 38.6%; stage 1: 43.3%); no significant outcome difference was found across the referral patterns. Hypertension and proteinuria are confirmed as independent risk factors.

CONCLUSIONS

CKD is a risk factor in pregnancy; all patients should be followed within dedicated programmes from stage 1. There is need for dedicated interventions and educational programmes for maximizing the diagnostic and therapeutic potentials in early CKD stages.

Saliva-based creatine kinase MB measurement as a potential point-of-care testing for detection of myocardial infarction

Myocardial infarction (MI) is the main cause of death all over the world. Biomarkers of cardiac necrosis are of great importance in the diagnosis of MI. The aim of this study was to determine probable changes of creatine kinase MB isoform (CK-MB) levels in saliva of patients with acute MI. A case-control study was carried out on 30 patients with acute MI who were hospitalized in Kamkar-Arabnia Hospital of Qom City and 30 healthy control subjects. CK-MB levels were measured by immunoinhibition assay in saliva and serum of patients and healthy individuals. Statistical analysis of the Student's t test and Pearson correlation coefficient was used. CK-MB levels showed a significant elevation in saliva and serum of patients with acute MI compared to healthy controls. Furthermore, there was a strong correlation between salivary levels of CK-MB and its serum values. Subsequent to an acute MI, there is a rise in salivary levels of CK-MB just as what occurs in the serum. Moreover, salivary levels of CK-MB reflect well its serum values. It seems that cardiac biomarker CK-MB is measurable in the saliva of patients with acute MI. Salivary CK-MB may serve as an easy-to-use diagnostic tool for point-of-care testing of acute MI.

Progestogens for treatment and prevention of pregnancy disorders

Progesterone appears to be the dominant hormone not only establishing a proper secretory endometrial development but also adequate decidualization to establish pregnancy and sustain pregnancy development. Progesterone is the natural immunoregulator to control the maternal immune system and not to reject the allogeneic fetus. There are two sources of progesterone: corpus luteum first and placenta later. Three progestogens can be used in pregnancy: (i) progesterone (per os, intravaginal and intramuscular), (ii) dydrogesterone (per os), and (iii) 17α-hydroxyprogesterone caproate (intramuscular). There are three indications, for which these progestogens can be clinically used either for treatment or prevention: (i) first trimester threatened and recurrent (habitual) abortion, (ii) premature labor/premature birth, and (iii) pre-eclampsia (hypertension in pregnancy). The available data are limited and only partially randomized. In threatened abortion the use of progesterone, dydrogesterone and 17α-hydroxyprogesterone caproate leads to a significant improved outcome, when at the time of threatened abortion a viable fetus has been ascertained by ultrasound. For prevention of recurrent abortion there are also some data indicating a significant effect compared with women without progestogen treatment. Prevention of preterm birth by progestogens (progesterone vaginally, orally and 17α-hydroxyprogesterone caproate intramuscularly) was significantly effective. The main study groups include pregnant women with a previous history of premature birth. However, also in women with shortened cervix use of progesterone seems to be helpful. The studies done so far in women with risk factors for pre-eclampsia or established pre-eclampsia were based on parenteral progesterone application. However, new studies are urgently needed.

Pregnancy and chronic kidney disease: a challenge in all CKD stages

BACKGROUND AND OBJECTIVES

Chronic kidney disease (CKD) is a challenge for pregnancy. Its recent classification underlines the importance of its early phases. This study's aim was to evaluate outcomes of pregnancy according to CKD stage versus low-risk pregnancies followed in the same center.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

The prospective analysis was conducted from January 2000 to May 2009 with the start of observation at referral and end of observation 1 month after delivery. Ninety-one singleton deliveries were studied; 267 "low-risk" singleton pregnancies served as controls. Because of the lack of hard end points (death, start of dialysis), surrogate end points were analyzed (cesarean section, prematurity, neonatal intensive care).

RESULTS

CKD outcome was worse than physiologic pregnancies: preterm delivery (44% versus 5%); cesarean section (44% versus 25%); and need for neonatal intensive care (26% versus 1%). The differences were highly significant in stage 1 CKD (61 cases) versus controls (CKD stage 1: cesarean sections = 57%, preterm delivery = 33%, intensive care = 18%). In CKD, proteinuria and hypertension were correlated with outcomes [proteinuria dichotomized at 1 g/24 h at referral: need for intensive care, relative risk (RR) = 4.16 (1.05 to 16.46); hypertension: preterm delivery, RR = 7.24 (2.30 to 22.79); cesarean section, RR = 5.70 (1.69 to 19.24)]. Statistical significance across stages was reached for preterm delivery [RR = 3.32 (1.09 to 10.13)].

CONCLUSIONS

CKD is a challenge for pregnancy from early stages. Strict follow-up is needed for CKD patients, even when there is normal renal function.