Pregnancy state before the onset of labor: a holistic mechanical perspective

Successful pregnancy highly depends on the complex interaction between the uterine body, cervix, and fetal membrane. This interaction is synchronized, usually following a specific sequence in normal vaginal deliveries: (1) cervical ripening, (2) uterine contractions, and (3) rupture of fetal membrane. The complex interaction between the cervix, fetal membrane, and uterine contractions before the onset of labor is investigated using a complete third-trimester gravid model of the uterus, cervix, fetal membrane, and abdomen. Through a series of numerical simulations, we investigate the mechanical impact of (i) initial cervical shape, (ii) cervical stiffness, (iii) cervical contractions, and (iv) intrauterine pressure. The findings of this work reveal several key observations: (i) maximum principal stress values in the cervix decrease in more dilated, shorter, and softer cervices; (ii) reduced cervical stiffness produces increased cervical dilation, larger cervical opening, and decreased cervical length; (iii) the initial cervical shape impacts final cervical dimensions; (iv) cervical contractions increase the maximum principal stress values and change the stress distributions; (v) cervical contractions potentiate cervical shortening and dilation; (vi) larger intrauterine pressure (IUP) causes considerably larger stress values and cervical opening, larger dilation, and smaller cervical length; and (vii) the biaxial strength of the fetal membrane is only surpassed in the cases of the (1) shortest and most dilated initial cervical geometry and (2) larger IUP.

Modeling of the biomechanical behavior and growth of the human uterus during pregnancy

Premature birth poses a challenge to public health, with one in ten babies being born prematurely worldwide. The pathological distension of the uterus can create tension in the uterine wall, triggering contractions that may lead to birth, including premature birth. While there has been an increase in the use of computational models to study pregnancy in recent years, ethical challenges have limited research on the mechanical properties of the uterus during gestation. This study proposes a biomechanical model based on a stretch-driven growth mechanism to describe uterine evolution during the second half of the gestational period. The constitutive model employed is anisotropic, reflecting the presence of fibers in uterine tissue, and it is also considered incompressible. The geometric model representing the uterine body was derived from truncated ellipsoids, subject to intrauterine pressure as loading. Simulation results indicate that the proposed model is effective in reproducing growth patterns documented in the literature, such as simultaneous increases in intrauterine volume and uterine tissue volume, accompanied by a reduction in uterine wall thickness within limits reported in experimental data.

Modern Management of Pregnancy in Systemic Lupus Erythematosus: From Prenatal Counseling to Postpartum Support

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease that predominantly affects women of childbearing age. Pregnancy in SLE patients poses unique challenges due to the potential impact on maternal and fetal outcomes. We provide an overview of the management of SLE during pregnancy, including preconception risk stratification and counseling, treatment, and disease activity monitoring. These assessments are critical to minimize maternal and fetal adverse events in pregnant patients with SLE. Disease flares, preeclampsia, antiphospholipid syndrome complications, and maternal mortality are the major risks for a woman with SLE during gestation. Timely treatment of SLE relapse, differentiation of preeclampsia from lupus nephritis, and tailored management for antiphospholipid syndrome are essential for a successful pregnancy. Fetal outcomes include neonatal lupus (NL), preterm birth, cesarean delivery, fetal growth restriction (FGR), and small-for-gestational-age (SGA) infants. We focused on NL, linked to maternal anti-Ro/SS-A and anti-La/SS-B antibodies, which can lead to various manifestations, particularly cardiac abnormalities, in newborns. While there is a common consensus regarding the preventive effect of hydroxychloroquine, the role of echocardiographic monitoring and fluorinated steroid treatment is still debated. Finally, close postpartum monitoring and counseling for subsequent pregnancies are crucial aspects of care.

Recent Advances and Challenges in the Early Diagnosis and Treatment of Preterm Labor

Preterm birth (PTB) is the primary cause of neonatal mortality and long-term disabilities. The unknown mechanism behind PTB makes diagnosis difficult, yet early detection is necessary for controlling and averting related consequences. The primary focus of this work is to provide an overview of the known risk factors associated with preterm labor and the conventional and advanced procedures for early detection of PTB, including multi-omics and artificial intelligence/machine learning (AI/ML)- based approaches. It also discusses the principles of detecting various proteomic biomarkers based on lateral flow immunoassay and microfluidic chips, along with the commercially available point-of-care testing (POCT) devices and associated challenges. After briefing the therapeutic and preventive measures of PTB, this review summarizes with an outlook.

Maternal and fetal outcomes of SLE in pregnancy: a literature review

Systemic Lupus Erythematosus (SLE) is an auto-immune disease in which the immune system assaults its tissues. We aimed to analyse the maternal and foetal outcomes during pregnancy in SLE mothers. A literature search was conducted by two investigators to assess SLE's outcomes on maternal and foetal during pregnancies. We searched PubMed/Medline, Embase, and Google scholar to collect evidence from different research studies, draw the conclusion, and report it. In our investigation, we found out that SLE could cause a spectrum of complications during pregnancy, not only for the mother but also for the foetus. It could affect fertility and cause difficult pregnancies for the couple as well which includes certain complications such as: preterm labour and delivery, high blood pressure (preeclampsia), placental insufficiency, miscarriage or stillbirth, whereas in the foetus SLE can cause mortality, preterm birth, and neonatal lupus (a temporary condition in the baby caused by SLE-related antibodies) and structural abnormalities. The literature suggests that SLE could prove fatal for the foetus and induce many complications in the mother. However, this could be avoided if pregnancy is planned right from the start and proper management is provided to the mother during pregnancy and delivery.p.

Pregnancy in lupus: an updated consensus to guide best practice strategies

Background

Systemic lupus erythematosus is a multifaceted chronic relapsing autoimmune disease of unknown etiology. The disease has always been a serious diagnosis in women being a multisystem pathology that is classically encountered during the childbearing age posing serious systemic comorbidities with a potential impact on the functional performance, psychosocial status, and survival. In this article, we review critical issues related to the decision to conceive in female with lupus highlighting the impact of the diagnosis and disease activity status on the mother and the fetus, attempting to suggest a consensus to guide safe decision making for pregnancy with SLE.

Main body

The pleomorphic dysregulated immune nature of lupus in the presence of uncontrolled disease carries a higher risk of complicated pregnancy. Therefore, SLE pregnancies should be well planned and are usually encouraged if the disease is inactive (at least 6 months prior to conception) to ensure immune quiescence towards a safer outcome.

Conclusion

With the proper implementation of preconception counseling strategy, choice of the correct timing of conception, close monitoring of SLE flares with tight control, and the appreciation of the value of multidisciplinary management to best practice most young women with SLE can carry on successful pregnancies with favorable outcome.

Inflammation and oxidative stress as mediators of the impacts of environmental exposures on human pregnancy: Evidence from oxylipins

Inflammation and oxidative stress play major roles in healthy and pathological pregnancy. Environmental exposure to chemical pollutants may adversely affect maternal and fetal health in pregnancy by dysregulating these critical underlying processes of inflammation and oxidative stress. Oxylipins are bioactive lipids that play a major role in regulating inflammation and increasing lines of evidence point towards an importance in pregnancy. The biosynthetic production of oxylipins requires oxygenation of polyunsaturated fatty acids, which can occur through several well-characterized enzymatic and nonenzymatic pathways. This review describes the state of the science of epidemiologic evidence on oxylipin production in pregnancy and its association with 1) key pregnancy outcomes and 2) environmental exposures. We searched PubMed for studies of pregnancy that measured one or more oxylipin analytes during pregnancy or delivery. We evaluated oxylipin associations with three categories of adverse pregnancy outcomes, including preeclampsia, preterm birth, and fetal growth restriction, along with several categories of environmental pollutants. The majority of studies evaluated one to two oxylipins, most of which focused on oxylipins produced from nonenzymatic processes of oxidative stress. However, an increasing number of recent studies have leveraged technological advancements to profile a large number of oxylipins produced from distinct biosynthetic pathways. Although the literature indicated robust evidence that oxylipins produced via nonenzymatic pathways are associated with pregnancy outcomes and environmental exposures, evidence for enzymatically produced oxylipins showed that associations may differ between biosynthetic pathways. Along with summarizing this evidence, we review promising therapeutic options to regulate oxylipin production and provide a set of recommendations for future epidemiologic studies in these research areas. Further evidence is needed to improve our understanding of how oxylipins may act as key biological mediators for the adverse effects of environmental pollutants on pregnancy outcomes.

Sickle cell disease and the incidence and etiology of preterm birth

BACKGROUND

Medically indicated delivery can be defined as delivery owing to intervention for maternal or fetal well-being-most commonly because of preeclampsia or nonreassuring fetal status. Among the general population of the United States, approximately two-thirds of preterm deliveries are because of spontaneous labor and/or premature rupture of membranes, whereas the remaining one-third are medically indicated. Despite the increased risk of preterm birth among women with sickle cell disease, the specific etiologies have not been described in the medical literature. Without an understanding of the etiologies of preterm birth in women with sickle cell disease, it is difficult to develop preventative strategies.

OBJECTIVE

This study aimed to estimate the incidence and etiologies of preterm births (spontaneous vs medically indicated) in women with sickle cell disease.

STUDY DESIGN

This was a retrospective, institutional review board-exempt cohort study of deliveries at >20 weeks' gestation in women with sickle cell disease at Duke University Hospital (2013-2020). We screened pregnancy-linked hospitalizations with International Classification of Diseases-9/10 codes for sickle cell disease (n=373). We excluded cases of pregnancy with <20 weeks' gestation, multiple gestation, or unproven sickle cell disease. We limited inclusion to deliveries within Duke (n=66). We compared the proportion of preterm birth cases between the sickle cell disease cohort and the overall Duke population (n=18,365), and the proportion of spontaneous vs medically indicated preterm births between the sickle cell disease cohort and a racially matched US population.

RESULTS

Of the 66 pregnancies, 65 occurred in patients who self-described as Black (98.5%). There were 60.6% (n=40) term and 39.4% (n=26) preterm births vs 85.9% term (n=15,771) and 14.1% preterm (n=2594) births in the Duke population as a whole. The sickle cell disease cohort was nearly 3 times more likely to deliver preterm than the Duke cohort (risk ratio, 2.79; 95% confidence interval, 2.06-3.77; P<.001). Among the 26 preterm births in the sickle cell disease cohort, 30.8% (n=8) were spontaneous and 69.2% (n=18) were medically indicated. In the US Black population comparison cohort, 65.4% (n=392,984) of preterm births were spontaneous and 34.6% (n=207,614) were medically indicated. The sickle cell disease cohort had 2 times the risk of medically indicated preterm birth compared with the US population cohort (risk ratio, 2.00; 95% confidence interval, 1.55-2.59; P<.001).

CONCLUSION

Maternal sickle cell disease confers nearly triple the risk of preterm birth, which is twice as likely to be medically indicated.

Placental damage in pregnancies with systemic lupus erythematosus: A narrative review

Systemic lupus erythematosus (SLE) is a chronic inflammatory autoimmune disease of unknown cause, which mainly affects women of childbearing age, especially between 15 and 55 years of age. During pregnancy, SLE is associated with a high risk of perinatal morbidity and mortality. Among the most frequent complications are spontaneous abortion, fetal death, prematurity, intrauterine Fetal growth restriction (FGR), and preeclampsia (PE). The pathophysiology underlying obstetric mortality and morbidity in SLE is still under investigation, but several studies in recent years have suggested that placental dysfunction may play a crucial role. Understanding this association will contribute to developing therapeutic options and improving patient management thus reducing the occurrence of adverse pregnancy outcomes in this group of women. In this review, we will focus on the relationship between SLE and placental insufficiency leading to adverse pregnancy outcomes.

Genital mycoplasma infection and spontaneous preterm birth outcome: a prospective cohort study

OBJECTIVE

To assess the risk of spontaneous preterm birth (sPTB) associated with genital mycoplasma infection in asymptomatic women.

DESIGN

Prospective cohort.

SETTING

Public and private health services in Ribeirão Preto, SP, Brazil.

POPULATION

A cohort of 1349 asymptomatic women with a singleton pregnancy at 20-25 weeks of gestation.

METHODS

Participants completed a sociodemographic and clinical history questionnaire during the prenatal visit and provided cervicovaginal samples for the evaluation of Mycoplasma hominis (Mh), Ureaplasma spp. and bacterial vaginosis (BV). For gestational outcome, information about the delivery was assessed and sPTB was defined as a birth that occurred before 37 weeks of gestation. The association between variables and the risk of sPTB was evaluated using logistic regression analysis to estimate the odds ratios (ORs).

MAIN OUTCOME MEASURES

Genital mycoplasma infection and prematurity.

RESULTS

The prevalence of sPTB and genital mycoplasma was 6.8 and 18%, respectively. The infection was not a risk factor for sPTB (aOR 0.66, 95% CI 0.32-1.35), even when Mh and Ureaplasma spp. were found together (P = 0.83). Pregnant women with genital mycoplasma infections had greater BV (P < 0.0001), but this vaginal microbiota condition was not associated with sPTB (P = 0.35). Regarding the risk factors associated with sPTB, a previous history of sPTB (aOR 12.06, 95% CI 6.21-23.43) and a cervical length of ≤2.5 cm (aOR 3.97, 95% CI 1.67-9.47) were significant.

CONCLUSIONS

Genital mycoplasma infection was not a risk factor for sPTB, even in the presence of other abnormal vaginal microbiota.

TWEETABLE ABSTRACT

Genital mycoplasma infection was not a risk for sPTB, even when associated with bacterial vaginosis (BV).

Low-intensity physical activity may protect pregnant women against spontaneous preterm labour: a prospective case-control study

The innate immune system plays a significant role in onset of parturition. Maternal antenatal physical activity can influence immune function and timing of labour. We examined physical activity patterns and concentration of 19 cytokines at 16 and 27 weeks gestational age (GA), in peripheral plasma of 28 asymptomatic women who later had spontaneous preterm labour (SPTL, <37 weeks GA) and 52 women who later delivered at term (TL; ≥37 weeks GA). This nested case-control study used data from the Ontario Birth Study cohort. Exercise was assessed using the International Physical Activity Questionnaire, and cytokines were analyzed using Luminex assays. There was no significant difference in exercise patterns between SPTL and TL subjects. Plasma concentration of interleukin (IL)-10 was significantly higher in SPTL women at 16 and 27 weeks, while tumour necrosis factor alpha (TNF-α), IL-8, and monocyte chemoattractant protein (MCP)-1 concentrations were increased at 27 weeks GA (p < 0.05). Concentration of IL-10 was negatively correlated with the amount of reported walking (ρ = −0.264, p = 0.03). Women should be encouraged to partake in low-intensity exercise throughout pregnancy, as it may confer a protective effect against SPTL through IL-10–mediated pathways. Additionally, plasma cytokine analysis at 27 weeks GA may be useful for predicting SPTL in asymptomatic women.

Novelty: In women that delivered preterm, plasma levels of anti-inflammatory cytokine IL-10 were significantly elevated at 16 and 27 weeks of gestation. Plasma levels of IL-10 were negatively correlated with the amount of reported walking. Concentration of IL-8, MCP-1 and TNF-α were increased in plasma of asymptomatic women that subsequently deliver preterm.

Maternal gut microbiota reflecting poor diet quality is associated with spontaneous preterm birth in a prospective cohort study

BACKGROUND

A processed diet, high in fat and low in fiber, is associated with differences in the gut microbiota and adverse health outcomes in humans; however, little is known about the diet-microbiota relation and its impact on pregnancy. Spontaneous preterm birth (SPTB), a pregnancy outcome with serious short- and long-term consequences, occurs more frequently in black and in obese women in the United States.

OBJECTIVES

In a prospective, case-control sample matched for race and obesity (cases = 16, controls = 32), we compared the fecal gut microbiota, fecal and plasma metabolites, and diet in the late second trimester. We hypothesized that a Western diet would be associated with reduced microbiota richness and a metabolic signature predicting incidence of SPTB.

METHODS

The fecal microbiota was characterized by 16S-tagged sequencing and untargeted metabolomics was used to analyze both plasma and fecal metabolites. Wilcoxon's rank-sum test was used for the comparison of microbiota genera, α-diversity, fecal and plasma metabolites, and dietary variables between term and SPTB. β-Diversity was analyzed using permutational multivariate ANOVA, and metabolite associations were assessed by module analysis.

RESULTS

A decrease in α-diversity was strongly associated with the development of SPTB, especially in the taxonomic class of Betaproteobacteria. Of 824 fecal metabolites, 22 metabolites (mostly lipids) differed between cases and controls (P < 0.01), with greater DHA (22:6n-3) and EPA (20:5n-3) in cases [false discovery rate (FDR) < 0.2]. The most significant fecal metabolite module (FDR-adjusted P = 0.008) was dominated by DHA and EPA. Dietary saturated fat (primarily palmitate) intake was greater in cases (31.38 ± 7.37 compared with 26.08 ± 8.62 g, P = 0.045) and was positively correlated with fecal DHA and EPA (P < 0.05).

CONCLUSIONS

Reduced α-diversity of the gut microbiota and higher excretion of omega-3 (n-3) fatty acids in stool may provide a novel biomarker signature predicting SPTB in women with a low-fiber, high-fat diet. Further investigation of these markers in a larger sample is needed for validation.

Pregnancy in systemic lupus erythematosus

OBJECTIVES

Systemic lupus erythematosus (SLE) is a chronic illness that often affects women of reproductive age. The objectives of this article are to review the impact of SLE on pregnancy and current management strategies, including commonly used therapies.

METHODS

We conducted a review of available literature on the clinical course of SLE, diagnosis, management and pregnancy complications.

RESULTS

SLE has a variable clinical course characterized by flares and periods of remission and can present unique challenges in the management of obstetric patients. Pregnancy in patients with SLE is associated with multiple risks, including fetal loss, preterm birth, fetal growth restriction, and hypertensive disease. With advancements in disease treatment, many women have favorable pregnancy outcomes, but appropriate preconception counseling and disease management remain important tools in reducing complications.

CONCLUSION

Given the implications SLE can have on women of reproductive age and in pregnancy, understanding the disease course and management is important in order to optimize pregnancy outcomes.

Risk of adverse obstetric outcomes in Japanese women with systemic lupus erythematosus: The Japan Environment and Children's Study

Systemic lupus erythematosus, simply known as lupus, is associated with adverse obstetric outcomes. This study evaluated the incidence of preterm births (before 37 and 34 weeks), low birthweight infants (<2500 g and <1500 g), small-for-gestational age infants, preterm premature rupture of membranes, and gestational hypertension in mothers with lupus and compared them with those of the Japanese general population. Data from participants in the Japan Environment and Children's Study who gave birth between 2011 and 2014 were collected. Only participants with singleton pregnancies were included. Adjusted odds ratios for the variables were calculated using a logistic regression model, with a general population as the reference. In total, 88,017 participants were included in the analysis, and 63 of them had lupus. The adjusted odds ratios of preterm births before 37 and 34 weeks, low birthweight infants <2500 g and <1500 g, small-for-gestational age infants, and preterm premature rupture of membranes in the systemic lupus erythematosus group were 8.1 (95% CI, 4.7-14.1), 5.2 (1.6-16.5), 6.5 (3.9-10.8), 5.4 (1.3-22.4), 2.9 (1.4-5.9), and 12.1 (5.7-25.5), respectively. The adjusted odds ratio of gestational hypertension was 1.4 (0.4-4.5). This study revealed increased risk of preterm births, low birthweight infants, small-for-gestational age infants, and preterm premature rupture of membranes in patients with lupus when compared with those in the general population.

Dysregulation of bile acids increases the risk for preterm birth in pregnant women

Preterm birth (PTB) is the leading cause of perinatal mortality and newborn complications. Bile acids are recognized as signaling molecules regulating a myriad of cellular and metabolic activities but have not been etiologically linked to PTB. In this study, a hospital-based cohort study with 36,755 pregnant women is conducted. We find that serum total bile acid levels directly correlate with the PTB rates regardless of the characteristics of the subjects and etiologies of liver disorders. Consistent with the findings from pregnant women, PTB is successfully reproduced in mice with liver injuries and dysregulated bile acids. More importantly, bile acids dose-dependently induce PTB with minimal hepatotoxicity. Furthermore, restoring bile acid homeostasis by farnesoid X receptor activation markedly reduces PTB and dramatically improves newborn survival rates. The findings thus establish an etiologic link between bile acids and PTB, and open an avenue for developing etiology-based therapies to prevent or delay PTB.

Protein Profile Changes in Circulating Placental Extracellular Vesicles in Term and Preterm Births: A Longitudinal Study

Spontaneous preterm birth (PTB) is a major obstetrical problem around the globe and the mechanisms leading to PTB are unclear. Recently, changes in the circulating levels of placental extracellular vesicles (EVs) during pregnancy have been associated with various pregnancy complications. However, progress in the field is hindered by the inability to isolate placental EVs from the maternal circulation. A longitudinal study design was used to determine the protein cargo present in circulating placental EVs in maternal plasma of term and PTB across gestation (ie, first, second, and third trimester). Placental-derived EVs were enriched from the total EV population based on their expression of membrane-bound placental alkaline phosphatase (PLAP). A quantitative, information-independent acquisition (sequential windowed acquisition of all theoretical mass spectra [SWATH]) approach identified and quantified the placental EV protein contents. PLAP+ EVs did not change in characteristics (size, shape, and markers) but did differ in numbers across gestation with low levels in PTB. A comparison analysis between the PLAP+ EV proteome from term and PTB revealed 96 proteins differing significantly (P < 0.05, false discovery rate 1%) across gestation. Bioinformatics analysis of differentially expressed proteins revealed consistent upregulation of inflammatory pathways in both upregulation of epithelial mesenchymal transition pathways at term and downregulation of coagulation/complement activation in preterm. Characterization of the proteomic profile in PLAP+ EVs across gestation demonstrates dramatic changes, which might be used to understand the biological process associated with early parturition and develop biomarkers for predicting high-risk status for PTB.

EBF1 Gene mRNA Levels in Maternal Blood and Spontaneous Preterm Birth

Genetic variants of six genes (EBF1, EEFSEC, AGTR2, WNT4, ADCY5, and RAP2C) have been linked recently to gestational duration and/or spontaneous preterm birth (sPTB). Our goal was to examine sPTB in relation to maternal blood mRNA levels of these genes. We used a public gene expression dataset (GSE59491) derived from maternal blood in trimesters 2 and 3 that included women with sPTB (n = 51) and term births (n = 106) matched for maternal age, race/ethnicity, pre-pregnancy body mass index, smoking during pregnancy, and parity. T tests were used to examine mRNA mean differences (sPTB vs term) within and across trimesters, and logistic regression models with mRNA quartiles were applied to assess associations between candidate gene mRNA levels and sPTB. Based on these analyses, one significant candidate gene was used in a Gene Set Enrichment Analysis (GSEA) to identify related gene sets. These gene sets were then compared with the ones previously linked to sPTB in the same samples. Our results indicated that among women in the lowest quartile of EBF1 mRNA in the 2nd or 3rd trimester, the odds ratio for sPTB was 2.86 (95%CI 1.08, 7.58) (p = 0.0349, false discovery rate (FDR) = 0.18) and 4.43 (95%CI 1.57, 12.50) (p = 0.0049, FDR = 0.06), respectively. No other candidate gene mRNAs were significantly associated with sPTB. In GSEA, 24 downregulated gene sets were correlated with 2nd trimester low EBF1 mRNA and part of previous sPTB-associated gene sets. In conclusion, mRNA levels of EBF1 in maternal blood may be useful in detecting increased risk of sPTB as early as 2nd trimester. The potential underlying mechanism might involve maternal-fetal immune and cell cycle/apoptosis pathways.

Alcohol Intake in Early Pregnancy and Spontaneous Preterm Birth: A Cohort Study

BACKGROUND

Limited research has addressed whether maternal alcohol intake in early pregnancy increases the risk of spontaneous preterm birth. In the current study, we examined how alcohol binge drinking and weekly alcohol intake in early pregnancy were associated with spontaneous preterm birth in a contemporary cohort of Danish women.

METHODS

We included 15,776 pregnancies of 14,894 women referred to antenatal care at Copenhagen University Hospital, Denmark, between 2012 and 2016. Self-reported alcohol intake in early pregnancy was obtained from a Web-based questionnaire completed prior to the women's first visit at the department. Information on spontaneous preterm birth was extracted from the Danish Medical Birth Register. Adjusted hazard ratios (aHRs) with 95% confidence intervals (CIs) of spontaneous preterm birth according to self-reported alcohol binge drinking and weekly intake of alcohol in early pregnancy were derived from Cox regression.

RESULTS

Women reporting 1, 2, and ≥ 3 binge drinking episodes had an aHR for spontaneous preterm birth of 0.88 (95% CI 0.68 to 1.14), 1.34 (95% CI 0.98 to 1.82), and 0.93 (95% CI 0.62 to 1.41), respectively, compared to women with no binge drinking episodes. Women who reported an intake of ≥ 1 drink per week on average had an aHR for spontaneous preterm birth of 1.09 (95% CI 0.63 to 1.89) compared to abstainers. When restricting to nulliparous women or cohabiting women with ≥ 3 years of higher education, this estimate was 1.28 (95% CI 0.69 to 2.40) and 1.20 (95% CI 0.67 to 2.15), respectively.

CONCLUSION

We found no evidence that maternal alcohol intake in early pregnancy was associated with a higher risk of spontaneous preterm birth, neither for alcohol binge drinking nor for a low average weekly intake of alcohol.

Oxidative stress - Related spontaneous preterm delivery challenges in causality determination, prevention and novel strategies in reduction of the sequelae

Spontaneous preterm birth (PTB) is one of the major complications of pregnancy and the main cause of neonatal mortality and morbidity. Despite the efforts devoted to the understanding of this obstetrical syndrome and improved medical care, there has been a tendency for the PTB rate to increase in the last decades globally. The costs of the screening for spontaneous PTB, its management, and treatment of the sequelae represent a major burden to the health service economy of high-income countries. In this scenario, it has been widely acknowledged that oxidative stress (OS) plays an important role in the pathogenicity of human disease in wide range of areas of medicine. There is an emerging evidence that an imbalance between pro-and-antioxidants may be associated with spontaneous PTB. However, there are still many controversies on the mechanisms by which OS are involved in the pathogenesis of prematurity. Moreover, the crucial question whether the OS is the cause or consequence of the disease is yet to be answered. The purpose of this article is to briefly summarize the current knowledge and controversies on oxidative stress-related spontaneous PTB and to give a critical approach on future perspectives on this topic as a classical example of translational medicine. Placenta-mediated pregnancy adverse outcome associated with OS leading to iatrogenic PTB (e.g. pre-eclampsia, intrauterine growth restriction, gestational diabetes) will not be discussed.

Comparative analysis of myometrial and vascular smooth muscle cells to determine optimal cells for use in drug discovery

Novel therapeutic regulators of uterine contractility are needed to manage preterm labor, induce labor and control postpartum hemorrhage. Therefore, we previously developed a high-throughput assay for large-scale screening of small molecular compounds to regulate calcium-mobilization in primary mouse uterine myometrial cells. The goal of this study was to select the optimal myometrial cells for our high-throughput drug discovery assay, as well as determine the similarity or differences of myometrial cells to vascular smooth muscle cells (VSMCs)-the most common off-target of current myometrial therapeutics. Molecular and pharmacological assays were used to compare myometrial cells from four sources: primary cells isolated from term pregnant human and murine myometrium, immortalized pregnant human myometrial (PHM-1) cells and immortalized non-pregnant human myometrial (hTERT-HM) cells. In addition, myometrial cells were compared to vascular SMCs. We found that the transcriptome profiles of hTERT-HM and PHM1 cells were most similar (r = 0.93 and 0.90, respectively) to human primary myometrial cells. Comparative transcriptome profiling of primary human myometrial transcriptome and VSMCs revealed 498 upregulated (p ≤ 0.01, log2FC≥1) genes, of which 142 can serve as uterine-selective druggable targets. In the high-throughput Ca²⁺-assay, PHM1 cells had the most similar response to primary human myometrial cells in OT-induced Ca²⁺-release (E_max = 195% and 143%, EC₅₀ = 30 nM and 120 nM, respectively), while all sources of myometrial cells showed excellent and similar robustness and reproducibility (Z' = 0.52 to 0.77). After testing a panel of 61 compounds, we found that the stimulatory and inhibitory responses of hTERT-HM cells were highly-correlated (r = 0.94 and 0.95, respectively) to human primary cells. Moreover, ten compounds were identified that displayed uterine-selectivity (≥5-fold E_max or EC₅₀ compared to VSMCs). Collectively, this study found that hTERT-HM cells exhibited the most similarity to primary human myometrial cells and, therefore, is an optimal substitute for large-scale screening to identify novel therapeutic regulators of myometrial contractility. Moreover, VSMCs can serve as an important counter-screening tool to assess uterine-selectivity of targets and drugs given the similarity observed in the transcriptome and response to compounds.

Pre-pregnancy or first-trimester risk scoring to identify women at high risk of preterm birth

Objective To develop a pre-pregnancy or first-trimester risk score to identify women at high risk of preterm birth. Study design In this retrospective cohort analysis, the sample was drawn from California singleton livebirths from 2007 to 2012 with linked birth certificate and hospital discharge records. The dataset was divided into a training (2/3 of sample) and a testing (1/3 of sample) set for discovery and validation. Predictive models for preterm birth using pre-pregnancy or first-trimester maternal factors were developed using backward stepwise logistic regression on a training dataset. A risk score for preterm birth was created for each pregnancy using beta-coefficients for each maternal factor remaining in the final multivariable model. Risk score utility was replicated in a testing dataset and by race/ethnicity and payer for prenatal care. Results The sample included 2,339,696 pregnancies divided into training and testing datasets. Twenty-three maternal risk factors were identified including several that were associated with a two or more increased odds of preterm birth (preexisting diabetes, preexisting hypertension, sickle cell anemia, and previous preterm birth). Approximately 40% of women with a risk score ≥ 3.0 in the training and testing samples delivered preterm (40.6% and 40.8%, respectively) compared to 3.1-3.3% of women with a risk score of 0.0 [odds ratio (OR) 13.0, 95% confidence interval (CI) 10.7-15.8, training; OR 12.2, 95% CI 9.4-15.9, testing). Additionally, over 18% of women with a risk score ≥ 3.0 had an adverse outcome other than preterm birth. Conclusion Maternal factors that are identifiable prior to pregnancy or during the first-trimester can be used create a cumulative risk score to identify women at the lowest and highest risk for preterm birth regardless of race/ethnicity or socioeconomic status. Further, we found that this cumulative risk score could also identify women at risk for other adverse outcomes who did not have a preterm birth. The risk score is not an effective screening test, but does identify women at very high risk of a preterm birth.

Prediction of preterm birth with and without preeclampsia using mid-pregnancy immune and growth-related molecular factors and maternal characteristics

OBJECTIVE

To evaluate if mid-pregnancy immune and growth-related molecular factors predict preterm birth (PTB) with and without (±) preeclampsia.

STUDY DESIGN

Included were 400 women with singleton deliveries in California in 2009-2010 (200 PTB and 200 term) divided into training and testing samples at a 2:1 ratio. Sixty-three markers were tested in 15-20 serum samples using multiplex technology. Linear discriminate analysis was used to create a discriminate function. Model performance was assessed using area under the receiver operating characteristic curve (AUC).

RESULTS

Twenty-five serum biomarkers along with maternal age <34 years and poverty status identified >80% of women with PTB ± preeclampsia with best performance in women with preterm preeclampsia (AUC = 0.889, 95% confidence interval (0.822-0.959) training; 0.883 (0.804-0.963) testing).

CONCLUSION

Together with maternal age and poverty status, mid-pregnancy immune and growth factors reliably identified most women who went on to have a PTB ± preeclampsia.

The association between serum progesterone level and preterm delivery

OBJECTIVE

To investigate the association of serum progesterone level and preterm delivery.

METHODS

The present prospective cohort study enrolled women with singleton pregnancies attending their first prenatal visit at the outpatient specialist clinics at KK Women's and Children's Hospital, Singapore, between September 1, 2010, and August 31, 2014. Progesterone levels were measured at four clinical visits (visit 1: 9-14 weeks; visit 2: 18-22 weeks; visit 3: 28-32 weeks; visit 4: >34 weeks) and were compared (after adjusting for potential confounders) between patients who had term and preterm deliveries, and among subgroups of spontaneous preterm and iatrogenic preterm deliveries.

RESULTS

There were 708 patients included. Serum progesterone levels at visit 3 were higher in the preterm delivery group than in the term delivery group (P=0.036). The levels did not differ between the two groups at other visits (all P>0.05). In the subgroup analysis, progesterone levels were higher in the iatrogenic preterm delivery subgroup than the term subgroup at visits 1 and 3. A progesterone cut-off level of 304.5 nmol/L demonstrated 81.8% sensitivity, 40.1% specificity, and negative and positive predictive values of 97.5% and 7.2%, respectively, as a predictor of preterm delivery.

CONCLUSION

Higher serum progesterone levels at 28-32 weeks of pregnancy were observed in women who had preterm deliveries; it was weakly predictive of preterm delivery.

The therapeutic effect of mesenchymal stem cells on pulmonary myeloid cells following neonatal hyperoxic lung injury in mice

Background

Exposure to high levels of oxygen (hyperoxia) after birth leads to lung injury. Our aims were to investigate the modulation of myeloid cell sub-populations and the reduction of fibrosis in the lungs following administration of human mesenchymal stem cells (hMSC) to neonatal mice exposed to hyperoxia.

Method

Newborn mice were exposed to 90% O₂ (hyperoxia) or 21% O₂ (normoxia) from postnatal days 0–4. A sub-group of hyperoxia mice were injected intratracheally with 2.5X10⁵ hMSCs. Using flow cytometry we assessed pulmonary immune cells at postnatal days 0, 4, 7 and 14. The following markers were chosen to identify these cells: CD45⁺ (leukocytes), Ly6C⁺Ly6G⁺ (granulocytes), CD11b⁺CD11c⁺ (macrophages); macrophage polarisation was assessed by F4/80 and CD206 expression. hMSCs expressing enhanced green fluorescent protein (eGFP) and firefly luciferase (fluc) were administered via the trachea at day 4. Lung macrophages in all groups were profiled using next generation sequencing (NGS) to assess alterations in macrophage phenotype. Pulmonary collagen deposition and morphometry were assessed at days 14 and 56 respectively.

Results

At day 4, hyperoxia increased the number of pulmonary Ly6C⁺Ly6G⁺ granulocytes and F4/80^lowCD206^low macrophages but decreased F4/80^highCD206^high macrophages. At days 7 and 14, hyperoxia increased numbers of CD45⁺ leukocytes, CD11b⁺CD11c⁺ alveolar macrophages and F4/80^lowCD206^low macrophages but decreased F4/80^highCD206^high macrophages. hMSCs administration ameliorated these effects of hyperoxia, notably reducing numbers of CD11b⁺CD11c⁺ and F4/80^lowCD206^low macrophages; in contrast, F4/80^highCD206^high macrophages were increased. Genes characteristic of anti-inflammatory ‘M2’ macrophages (Arg1, Stat6, Retnla, Mrc1, Il27ra, Chil3, and Il12b) were up-regulated, and pro-inflammatory ‘M1’ macrophages (Cd86, Stat1, Socs3, Slamf1, Tnf, Fcgr1, Il12b, Il6, Il1b, and Il27ra) were downregulated in isolated lung macrophages from hyperoxia-exposed mice administered hMSCs, compared to mice without hMSCs. Hydroxyproline assay at day 14 showed that the 2-fold increase in lung collagen following hyperoxia was reduced to control levels in mice administered hMSCs. By day 56 (early adulthood), hMSC administration had attenuated structural changes in hyperoxia-exposed lungs.

Conclusions

Our findings suggest that hMSCs reduce neonatal lung injury caused by hyperoxia by modulation of macrophage phenotype. Not only did our cell-based therapy using hMSC induce structural repair, it limited the progression of pulmonary fibrosis.

Electronic supplementary material

The online version of this article (10.1186/s12931-018-0816-x) contains supplementary material, which is available to authorized users.

Antiplatelet Agents and the Prevention of Spontaneous Preterm Birth: A Systematic Review and Meta-analysis

OBJECTIVE

Spontaneous preterm birth is an important cause of neonatal mortality and morbidity. An increasing body of evidence suggests that uteroplacental ischemia plays an important role in the etiology of spontaneous preterm birth. We aimed to study whether antiplatelet agents reduce the risk of spontaneous preterm birth.

DATA SOURCES

We included data from an individual participant data meta-analysis of studies that had evaluated the effect of antiplatelet agents to reduce preeclampsia (Perinatal Antiplatelet Review of International Studies Individual Participant Data).

METHODS OF STUDY SELECTION

The meta-analysis included 31 studies that randomized women to low-dose aspirin-dipyridamole or placebo-no treatment as a primary preventive strategy for preeclampsia. For the current study we analyzed data from 17 trials (28,797 women) that supplied data on type of delivery (spontaneous compared with indicated birth).

TABULATION, INTEGRATION, AND RESULTS

Primary endpoints were spontaneous preterm birth at less than 37 weeks, less than 34 weeks, and less than 28 weeks of gestation. We analyzed outcomes for each trial separately using χ statistics and combined in an individual participant data meta-analysis using a binary logistic regression model. Women assigned to antiplatelet treatment compared with placebo or no treatment had a lower risk of spontaneous preterm birth at less than 37 weeks (relative risk [RR] 0.93, 95% confidence interval [CI] 0.86-0.996) and less than 34 weeks of gestation (RR 0.86, 95% CI 0.76-0.99). The RR of having a spontaneous preterm birth at less than 37 weeks of gestation was 0.83 (95% CI 0.73-0.95) for women who have had a previous pregnancy and 0.98 (95% CI 0.89-1.09) for women in their first pregnancy. The treatment effect was stable in all other prespecified subgroups.

CONCLUSION

Antiplatelet agents reduce spontaneous preterm birth in pregnant women at risk for preeclampsia.

Increased expression of toll-like receptors 2 and 9 is associated with reduced DNA methylation in spontaneous preterm labor

The cause of spontaneous preterm labor (sPTL) is not known, but it could be due to epigenetic alterations that increase the sensitivity of decidual tissue to inflammatory stimuli. We collected decidual tissue from women at term not in labor (TNL), women at term in labor (TL), and women with sPTL. Illumina Infinium HumanMethylation450 BeadChip analysis revealed significantly reduced DNA methylation for TLR-2 and TLR-9 in sPTL as compared to TL. Immunohistochemical staining documented significantly increased expression of TLR-2 and TLR-9 in decidual tissue of women with sPTL as compared to TL or TNL. TLR expression was not present in decidual cells, but localized to tissue leukocytes as revealed by staining for CD14, a macrophage antigen, and neutrophil elastase. Microarray analysis of inflammatory genes to assess innate immune response demonstrated marked increases in expression of inflammatory cytokines and chemokines in women with TL as compared to TNL. However, when sPTL was compared to TL, there was a further increase in inflammatory cytokines, and a remarkable increase in neutrophil chemokines. These results suggest that epigenetic mechanisms could play a role in increasing leukocyte infiltration, and increasing the sensitivity of decidual tissue to inflammatory stimuli that could precipitate labor prematurely.

Systemic lupus erythematosus and risk of preterm birth: a systematic review and meta-analysis of observational studies

We performed a meta-analysis to identify the association between systemic lupus erythematosus (SLE) and preterm birth. In this study, we studied the effects of SLE, SLE disease activity, a history of nephritis and active nephritis on preterm birth. Searches were conducted before 20 May 2016 of PubMed, Embase, Medline and Cochrane Library of literature and article reference lists. Eleven observational case-control studies and thirteen cohort studies met the inclusion criteria. The pooled relative risk (RR) for the risk of preterm birth in SLE patients versus controls was 2.05 (95% confidence interval (CI): 1.72-3.32); for active SLE patients versus inactive was 2.98 (95% CI: 2.32-3.83); for SLE patients with a history of lupus nephritis versus those without nephritis it was 1.62 (95% CI: 1.35-1.95); and for SLE patients with active nephritis versus those with quiescent nephritis it was 1.78 (95% CI: 1.17-2.70). In summary, this study identified a significant association in the above results. This association was more significant in active SLE patients versus inactive. With respect to SLE itself, active inflammation (such as disease activity) may be more hazardous for the management of the pregnancy. This suggests that it is essential to control disease activity in order to achieve a better outcome of SLE pregnancy.

Association between Exposure to Endocrine Disruptors in Drinking Water and Preterm Birth, Taking Neighborhood Deprivation into Account: A Historic Cohort Study

Background: The relationship between preterm birth (PTB) and endocrine disruptor exposure in drinking-water has only occasionally been studied. The objective of this work was to investigate the relation between exposure to atrazine metabolites, or atrazine/nitrate mixtures, in drinking-water during pregnancy and prevalence of PTB neonates, while taking neighborhood deprivation into account. Method: A historic cohort study in Deux-Sèvres, France, between 2005 and 2010 with a multiple imputation model for data of exposure to atrazine metabolites and a logistic regression were carried out. Results: We included 13,654 mother/neonate pairs living in 279 different census districts. The prevalence of PTB was 4%. Average atrazine metabolite concentration was 0.019 ± 0.009 (0.014–0.080) µg/L and 39% of mothers lived in less deprived areas. The individual data were associated with risk of PTB. The risk of PTB when exposed to highest concentration of atrazine metabolite adjusted for confounders, was ORa 1.625 95% CI [0.975; 2.710]. Taking, or not, neighborhood deprivation into account did not change the result. Exposure to atrazine/nitrate mixtures remained non-significant. Conclusions: Even if we took neighborhood deprivation into account, we could not show a significant relationship between exposure to atrazine metabolites, or mixtures, in drinking-water during the second trimester of pregnancy and PTB.

Epigenetic Biomarkers of Preterm Birth and Its Risk Factors

A biomarker is a biological measure predictive of a normal or pathogenic process or response. Biomarkers are often useful for making clinical decisions and determining treatment course. One area where such biomarkers would be particularly useful is in identifying women at risk for preterm delivery and related pregnancy complications. Neonates born preterm have significant morbidity and mortality, both in the perinatal period and throughout the life course, and identifying women at risk of delivering preterm may allow for targeted interventions to prevent or delay preterm birth (PTB). In addition to identifying those at increased risk for preterm birth, biomarkers may be able to distinguish neonates at particular risk for future complications due to modifiable environmental factors, such as maternal smoking or alcohol use during pregnancy. Currently, there are no such biomarkers available, though candidate gene and epigenome-wide association studies have identified DNA methylation differences associated with PTB, its risk factors and its long-term outcomes. Further biomarker development is crucial to reducing the health burden associated with adverse intrauterine conditions and preterm birth, and the results of recent DNA methylation studies may advance that goal.

High-Throughput Screening of Myometrial Calcium-Mobilization to Identify Modulators of Uterine Contractility

The uterine myometrium (UT-myo) is a therapeutic target for preterm labor, labor induction, and postpartum hemorrhage. Stimulation of intracellular Ca²⁺-release in UT-myo cells by oxytocin is a final pathway controlling myometrial contractions. The goal of this study was to develop a dual-addition assay for high-throughput screening of small molecular compounds, which could regulate Ca²⁺-mobilization in UT-myo cells, and hence, myometrial contractions. Primary murine UT-myo cells in 384-well plates were loaded with a Ca²⁺-sensitive fluorescent probe, and then screened for inducers of Ca²⁺-mobilization and inhibitors of oxytocin-induced Ca²⁺-mobilization. The assay exhibited robust screening statistics (Z´ = 0.73), DMSO-tolerance, and was validated for high-throughput screening against 2,727 small molecules from the Spectrum, NIH Clinical I and II collections of well-annotated compounds. The screen revealed a hit-rate of 1.80% for agonist and 1.39% for antagonist compounds. Concentration-dependent responses of hit-compounds demonstrated an EC₅₀ less than 10μM for 21 hit-antagonist compounds, compared to only 7 hit-agonist compounds. Subsequent studies focused on hit-antagonist compounds. Based on the percent inhibition and functional annotation analyses, we selected 4 confirmed hit-antagonist compounds (benzbromarone, dipyridamole, fenoterol hydrobromide and nisoldipine) for further analysis. Using an ex vivo isometric contractility assay, each compound significantly inhibited uterine contractility, at different potencies (IC₅₀). Overall, these results demonstrate for the first time that high-throughput small-molecules screening of myometrial Ca²⁺-mobilization is an ideal primary approach for discovering modulators of uterine contractility.

Cervical length, risk factors, and delivery outcomes among women with spontaneous preterm birth

OBJECTIVES

To evaluate differences in risk factors and delivery outcomes among women with spontaneous preterm birth (sPTB) with short (≤25 mm) versus normal (>25 mm) cervical length (CL).

METHODS

Secondary analysis of a prospective cohort study of singleton gestations between 18 0/7 and 23 6/7 weeks, without prior sPTB, undergoing universal transvaginal CL screening between 1 January 2012 and 31 December 2013. Only women with sPTB (<37 0/7 weeks) were included. Demographic characteristics, risk factors for sPTB, delivery outcomes and presentation of PTB were collected. The primary outcome was mean number of risk factors.

RESULTS

The cohort included 2071 women, of which 145 (7%) had PTB and 84 (4%) had sPTB. Sixty-nine (82%) women with sPTB had a CL >25 mm and 15 (18%) had a CL≤25 mm. Women with a short CL did not differ from women with normal CL with respect to demographic variables or mean number of risk factors (4.20 ± 2.11 versus 3.52 ± 1.97, p = 0.23), but they did deliver at a significantly earlier gestational age (25.0 ± 1.1 versus 34.6 ± 3.1 weeks, p < 0.01). The distribution of the presentation of sPTB was different in women with a short versus normal CL (p < 0.01).

CONCLUSIONS

Among women with sPTB, women with a short CL had similar number of risk factors, but were more likely to deliver at a significantly earlier gestational age. A short CL identifies women at risk for very early sPTB.

Maternal Asthma, Preterm Birth, and Risk of Bronchopulmonary Dysplasia

OBJECTIVE

To study the relationship between maternal asthma and the development of bronchopulmonary dysplasia (BPD).

STUDY DESIGN

Using a large population-based California cohort, we investigated associations between maternal asthma and preterm birth subtype, as well as maternal asthma and BPD. We used data from 2007-2010 maternal delivery discharge records of 2 009 511 pregnancies and International Classification of Diseases, Ninth Revision codes. Preterm birth was defined as <37 weeks gestational age (GA), with subgroups of <28 weeks, 28-32 weeks, and 33-37 weeks GA, as well as preterm subtype, defined as spontaneous, medically indicated, or unknown. Linkage between the 2 California-wide datasets yielded 21 944 singleton preterm infants linked to their mother's records, allowing estimation of the risk of BPD in mothers with asthma and those without asthma.

RESULTS

Maternal asthma was associated with increased odds (OR, 1.42; 95% CI, 1.38-1.46) of preterm birth at <37 weeks GA, with the greatest risk for 28-32 GA (aOR, 1.60; 95% CI, 1.47-1.74). Among 21 944 preterm infants, we did not observe an elevated risk for BPD in infants born to mothers with asthma (aOR, 1.03; 95% CI, 0.9-1.2). Stratification by maternal treatment with antenatal steroids revealed increased odds of BPD in infants whose mothers had asthma but did not receive antenatal steroids (aOR, 1.54; 95% CI, 1.15-2.06), but not in infants whose mothers had asthma and were treated with antenatal steroids (aOR, 0.85; 95% CI, 0.67-1.07).

CONCLUSION

Asthma in mothers who did not receive antenatal steroid treatment is associated with an increased risk of BPD in their preterm infants.

Pregnancy outcomes in HIV-positive women in Ukraine, 2000-12 (European Collaborative Study in EuroCoord): an observational cohort study

BACKGROUND

Women living with HIV are potentially at increased risk of adverse pregnancy outcomes, due to a range of factors, including immunosuppression, use of combination antiretroviral therapy (ART), and injecting drug use. Rates of mother-to-child transmission of HIV in Ukraine have declined to around 2-4%, but little is known about other pregnancy outcomes in this setting. We used data from an observational prospective cohort study to assess pregnancy outcomes among HIV-positive women in Ukraine.

METHODS

The European Collaborative Study (ECS) in EuroCoord is a continuing cohort study, established in Ukraine in 2000. Eligible women are those with a diagnosis of HIV infection before or during pregnancy (including intrapartum) who deliver liveborn babies at seven sites. Maternal sociodemographic, HIV-related, and delivery (mother and infant) data were collected with study-specific questionnaires. We used Poisson regression models to identify factors associated with preterm delivery (before 37 weeks' gestation) and small weight for gestational age (less than the tenth percentile of weight for gestational age), based on complete cases.

FINDINGS

Between January, 2000, and July, 2012, data were collected on 8884 HIV-positive mother and liveborn infant pairs. Median maternal age was 26·5 years (IQR 23·1-30·3). 832 (11%) women had WHO stage 3 or 4 HIV and 1474 (17%) had a history of injecting drug use. 7348 (83%) had received antenatal ART. Among 7435 for whom ART type was available, 4396 (50%) had received zidovudine monotherapy and 2949 (33%) combination ART. Preterm delivery was seen in 780 (9%, 95% CI 8-9) of 8860 births overall and in 77 (9%, 7-11) of 889 babies with small size for gestational age. Factors associated with preterm delivery were history of injecting drug use (adjusted risk ratio 1·64, 95% CI 1·38-1·95), no ART (2·94, 2·43-3·57 vs zidovudine monotherapy), antenatal combination ART (1·40, 1·14-1·73 vs zidovudine monotherapy), WHO stage 4 HIV (2·42, 1·71-3·41 vs WHO stage 1), and being in the most socially deprived group (1·38, 1·11-1·71). Small size for gestational age was associated with history of injecting drug use (adjusted RR 1·39, 95% CI 1·16-1·65), most socially deprived (1·32, 1·09-1·61), no ART (1·60, 1·32-1·94 vs zidovudine monotherapy), and antenatal combination ART (1·33, 1·12-1·60 vs zidovudine monotherapy).

INTERPRETATION

Some risk factors for adverse pregnancy outcomes were directly associated with HIV and treatment and others were shared with the general antenatal population. Monitoring of pregnancy outcomes in Ukraine will be important as use of antenatal combination ART increases.

FUNDING

European Union Seventh Framework Programme, Wellcome Trust.

Crosstalk between monocytes and myometrial smooth muscle in culture generates synergistic pro-inflammatory cytokine production and enhances myocyte contraction, with effects opposed by progesterone

Both term and preterm parturition are characterized by an influx of macrophages and neutrophils into the myometrium and cervix, with co-incident increased peripheral blood monocyte activation. Infection and inflammation are strongly implicated in the pathology of preterm labour (PTL), with progesterone considered a promising candidate for its prevention or treatment. In this study, we investigated the effect of monocytes on myometrial smooth muscle cell inflammatory cytokine production both alone and in response to LPS, a TLR4 agonist used to trigger PTL in vivo. We also investigated the effect of monocytes on myocyte contraction. Monocytes, isolated from peripheral blood samples from term pregnant women, were cultured alone, or co-cultured with PHM1-41 myometrial smooth muscle cells, for 24 h. In a third set of experiments, PHM1-41 myocytes were cultured for 24 h in isolation. Cytokine secretion was determined by ELISA or multiplex assays. Co-culture of monocytes and myocytes led to synergistic secretion of pro-inflammatory cytokines and chemokines including IL-6, IL-8 and MCP-1, with the secretion being further enhanced by LPS (100 ng/ml). The synergistic secretion of IL-6 and IL-8 from co-cultures was mediated in part by direct cell–cell contact, and by TNF. Conditioned media from co-cultures stimulated contraction of PHM1-41 myocytes, and the effect was inhibited by progesterone. Both progesterone and IL-10 inhibited LPS-stimulated IL-6 and IL-8 secretion from co-cultures, while progesterone also inhibited chemokine secretion. These data suggest that monocytes infiltrating the myometrium at labour participate in crosstalk that potentiates pro-inflammatory cytokine secretion, an effect that is enhanced by LPS, and can augment myocyte contraction. These effects are all partially inhibited by progesterone.

Intrauterine telemetry to measure mouse contractile pressure in vivo

A complex integration of molecular and electrical signals is needed to transform a quiescent uterus into a contractile organ at the end of pregnancy. Despite the discovery of key regulators of uterine contractility, this process is still not fully understood. Transgenic mice provide an ideal model in which to study parturition. Previously, the only method to study uterine contractility in the mouse was ex vivo isometric tension recordings, which are suboptimal for several reasons. The uterus must be removed from its physiological environment, a limited time course of investigation is possible, and the mice must be sacrificed. The recent development of radiometric telemetry has allowed for longitudinal, real-time measurements of in vivo intrauterine pressure in mice. Here, the implantation of an intrauterine telemeter to measure pressure changes in the mouse uterus from mid-pregnancy until delivery is described. By comparing differences in pressures between wild type and transgenic mice, the physiological impact of a gene of interest can be elucidated. This technique should expedite the development of therapeutics used to treat myometrial disorders during pregnancy, including preterm labor.

A possible role of aryl hydrocarbon receptor in spontaneous preterm birth

Preterm birth (PTB) is defined as birth before 37 weeks of gestation and is a leading cause of neonatal mortality and morbidity. To date, the etiology of spontaneous PTB (sPTB) remains unclear; however, intrauterine bacterial infection-induced inflammation is considered to be one of the major triggers. Aryl hydrocarbon receptor (AhR) is a ligand-dependent transcription factor. Upon activation, AhR signaling mediates many biological processes. AhR is abundantly expressed in human placentas, primarily in trophoblasts, and several fetal organs and tissues. The activation of AhR signaling can modulate inflammatory responses via promoting production of pro-inflammatory cytokines by the placenta and fetal membranes. These cytokines could enhance expression and/or activity of cyclooxygenase-2 (COX2) in human trophoblasts and amniotic epithelia, which in turn stimulate synthesis and release of prostaglandins (PGs; e.g., PGE2 and PGF2α). Given the discovery of a number of natural and endogenous AhR ligands in human, we hypothesize that in a subset of patients with high AhR expression in placentas and fetal membranes, repeated exposure to these AhR ligands hyperactivates AhR, inducing hyperactivation of the cytokines/COX2/PGs pathway, resulting in myometrial contractions, ultimately leading to sPTB. We further hypothesize that hyperactivation of this AhR pathway can induce sPTB either directly or in synergy with the bacterial infection. Proof of this hypothesis may provide a novel mechanism underlying sPTB.

First trimester biomarkers in the prediction of later pregnancy complications

Adverse obstetric outcomes, such as preeclampsia, preterm birth, gestational diabetes, and fetal growth restriction, are poorly predicted by maternal history and risk factors alone, especially in nulliparae. The ability to predict these outcomes from the first trimester would allow for the early initiation of prophylactic therapies, institution of an appropriate model and location of care, and recruitment of a truly "high risk" population to clinical trials of interventions to prevent or ameliorate these conditions. To this end, development of adequately sensitive and specific predictive tests for these outcomes has become a significant focus of perinatal research. This paper reviews the biomarkers involved in these multiparametric tests and also outlines the performance of these tests and issues regarding their introduction into clinical practice.

Maternal autoimmunity and adverse pregnancy outcomes

Some of the most dangerous and costly complications of human pregnancy, including premature labor and preeclampsia/eclampsia, have remained unexplained. While not noted by the authors of a recently published study of three distinct groups of patients with thyroid disease, their data may offer new insights into the interplay between thyroid autoimmune disease, indeed possibly autoimmunity in general, and human pregnancy. This editorial discusses a report of 223,512 pregnancies (2002-2008) from a retrospective U.S. cohort, the Consortium of Safe Labor, reported by Männistö et al. from the Epidemiology Branch, Division of Epidemiology, Statistics and Prevention Research, Eunice Kennedy Shriver National Institute for Child Health and Human Development, National Institutes of Health, Rockville, Maryland in the July 2013 issue of The Journal of Clinical Endocrinology and Metabolism. Reading between the lines of this publication offers potential insights into the etiologies of preeclampsia/eclampsia and of term as well as premature labor. Moreover, this study, unintentionally, may also offer insights into currently still only poorly understood immune dysfunction that links autoimmunity with adverse pregnancy outcomes.