A review of premature birth and subclinical infection

The hormonal control of parturition

Parturition is a complex physiological process that must occur in a reliable manner and at an appropriate gestation stage to ensure a healthy newborn and mother. To this end, hormones that affect the function of the gravid uterus, especially progesterone (P4), 17β-estradiol (E2), oxytocin (OT), and prostaglandins (PGs), play pivotal roles. P4 via the nuclear P4 receptor (PR) promotes uterine quiescence and for most of pregnancy exerts a dominant block to labor. Loss of the P4 block to parturition in association with a gain in prolabor actions of E2 are key transitions in the hormonal cascade leading to parturition. P4 withdrawal can occur through various mechanisms depending on species and physiological context. Parturition in most species involves inflammation within the uterine tissues and especially at the maternal-fetal interface. Local PGs and other inflammatory mediators may initiate parturition by inducing P4 withdrawal. Withdrawal of the P4 block is coordinated with increased E2 actions to enhance uterotonic signals mediated by OT and PGs to promote uterine contractions, cervix softening, and membrane rupture, i.e., labor. This review examines recent advances in research to understand the hormonal control of parturition, with focus on the roles of P4, E2, PGs, OT, inflammatory cytokines, and placental peptide hormones together with evolutionary biology of and implications for clinical management of human parturition.

Semi-quantitative metalloproteinase-8 rapid test for the prediction of adverse pregnancy outcomes in patients with preterm premature rupture of membranes

OBJECTIVE

We aimed to determine whether the semi-quantitative metalloproteinase-8 (MMP-8) bedside test is a worthwhile indicator in reflecting the severity of of intra-amniotic inflammation (IAI) and in predicting adverse pregnancy outcomes.

STUDY DESIGN

This retrospective cohort study comprised 76 singleton-pregnant women admitted to the Seoul National University Bundang Hospital with a diagnosis of preterm premature rupture of membranes (preterm PROM) between 20 weeks 0 days and 33 weeks 6 days of gestation who underwent trans-abdominal amniocentesis to confirm intra-amniotic infection by positive results for aerobic/anaerobic bacteria, fungi, and genital mycoplasma and evaluate lung maturity. The semi-quantitative MMP-8 rapid test kit employs a colourimetric assay to quantify MMP-8 levels in amniotic fluid (AF), expressing results from 0 to 100 percent. Participants were divided into three groups: group 1, including negative MMP-8 test with colour scale of 0 % (negative, n = 17); group 2, including positive MMP-8 test with colour scale < 51 % (weak positive, n = 21); and group 3, including positive MMP-8 test with colour scale of 51 %-100 % (strong positive, n = 38).

RESULTS

Approximately 78 % (59/76) of the participants showed a positive MMP-8 test result; all culture-proven AF samples (33.3 % [25/75]) yielded positive MMP-8 test, categorizing these patients into either group 2 or group 3. A significant trend was observed where the rate of positive culture-proven samples increased with the progression from group 1 (negative) to group 3 (strong positive). Both white blood cell counts in AF and maternal serum C-reactive protein levels were found to escalate with the progression of test results from negative to strong positive. This progression was associated with an increased risk of spontaneous preterm birth within 48 h, 7 days, and 14 days from amniocentesis and within 34 weeks of gestation.

CONCLUSION

The more the test results progress from negative to strong positive, the shorter the interval from amniocentesis to delivery becomes, and the higher the risk of intra-amniotic infection, spontaneous preterm delivery, and other perinatal complications. This relationship highlights the critical value of the semi-quantitative MMP-8 rapid test in predicting adverse pregnancy outcomes in patients with preterm PROM.

A pivotal role for the IL-1β and the inflammasome in preterm labor

During labor, monocytes infiltrate massively the myometrium and differentiate into macrophages secreting high levels of reactive oxygen species and of pro-inflammatory cytokines (i.e. IL-1β), leading to myometrial contraction. Although IL-1β is clearly implicated in labor, its function and that of the inflammasome complex that cleaves the cytokine in its active form, has never been studied on steps preceding contraction. In this work, we used our model of lipopolysaccharide-induced preterm labor to highlight their role. We demonstrated that IL-1β was secreted by the human myometrium during labor or in presence of infection and was essential for myometrial efficient contractions as its blockage with an IL-1 receptor antagonist (Anakinra) or a neutralizing antibody completely inhibited the induced contractions. We evaluated the implication of the inflammasome on myometrial contractions and differentiation stages of labor onset. We showed that the effects of macrophage-released IL-1β in myometrial cell transactivation were blocked by inhibition of the inflammasome, suggesting that the inflammasome by producing IL-1β was essential in macrophage/myocyte crosstalk during labor. These findings provide novel innovative approaches in the management of preterm labor, specifically the use of an inflammasome inhibitor to block the precursor stages of labor before the acquisition of the contractile phenotype.

Blockade of IL-6R prevents preterm birth and adverse neonatal outcomes

BACKGROUND

Preterm birth preceded by spontaneous preterm labour often occurs in the clinical setting of sterile intra-amniotic inflammation (SIAI), a condition that currently lacks treatment.

METHODS

Proteomic and scRNA-seq human data were analysed to evaluate the role of IL-6 and IL-1α in SIAI. A C57BL/6 murine model of SIAI-induced preterm birth was developed by the ultrasound-guided intra-amniotic injection of IL-1α. The blockade of IL-6R by using an aIL-6R was tested as prenatal treatment for preterm birth and adverse neonatal outcomes. QUEST-MRI evaluated brain oxidative stress in utero. Targeted transcriptomic profiling assessed maternal, foetal, and neonatal inflammation. Neonatal biometrics and neurodevelopment were tested. The neonatal gut immune-microbiome was evaluated using metagenomic sequencing and immunophenotyping.

FINDINGS

IL-6 plays a critical role in the human intra-amniotic inflammatory response, which is associated with elevated concentrations of the alarmin IL-1α. Intra-amniotic injection of IL-1α resembles SIAI, inducing preterm birth (7% vs. 50%, p = 0.03, Fisher's exact test) and neonatal mortality (18% vs. 56%, p = 0.02, Mann-Whitney U-test). QUEST-MRI revealed no foetal brain oxidative stress upon in utero IL-1α exposure (p > 0.05, mixed linear model). Prenatal treatment with aIL-6R abrogated IL-1α-induced preterm birth (50% vs. 7%, p = 0.03, Fisher's exact test) by dampening inflammatory processes associated with the common pathway of labour. Importantly, aIL-6R reduces neonatal mortality (56% vs. 22%, p = 0.03, Mann-Whitney U-test) by crossing from the mother to the amniotic cavity, dampening foetal organ inflammation and improving growth. Beneficial effects of prenatal IL-6R blockade carried over to neonatal life, improving survival, growth, neurodevelopment, and gut immune homeostasis.

INTERPRETATION

IL-6R blockade can serve as a strategy to treat SIAI, preventing preterm birth and adverse neonatal outcomes.

FUNDING

NICHD/NIH/DHHS, Contract HHSN275201300006C. WSU Perinatal Initiative in Maternal, Perinatal and Child Health.

Evidence for the participation of CHCHD2/MNRR1, a mitochondrial protein, in spontaneous labor at term and in preterm labor with intra-amniotic infection

OBJECTIVE

Intra-amniotic inflammation (IAI), associated with either microbe (infection) or danger signals (sterile), plays a major role in the pathophysiology of preterm labor and delivery. Coiled-Coil-Helix-Coiled-Coil-Helix Domain Containing 2 (CHCHD2) [also known as Mitochondrial Nuclear Retrograde Regulator 1 (MNRR1)], a mitochondrial protein involved in oxidative phosphorylation and cell survival, is capable of sensing tissue hypoxia and inflammatory signaling. The ability to maintain an appropriate energy balance at the cellular level while adapting to environmental stress is essential for the survival of an organism. Mitochondrial dysfunction has been observed in acute systemic inflammatory conditions, such as sepsis, and is proposed to be involved in sepsis-induced multi-organ failure. The purpose of this study was to determine the amniotic fluid concentrations of CHCHD2/MNRR1 in pregnant women, women at term in labor, and those in preterm labor (PTL) with and without IAI.

METHODS

This cross-sectional study comprised patients allocated to the following groups: (1) mid-trimester (n = 16); (2) term in labor (n = 37); (3) term not in labor (n = 22); (4) PTL without IAI who delivered at term (n = 25); (5) PTL without IAI who delivered preterm (n = 47); and (6) PTL with IAI who delivered preterm (n = 53). Diagnosis of IAI (amniotic fluid interleukin-6 concentration ≥2.6 ng/mL) included cases associated with microbial invasion of the amniotic cavity and those of sterile nature (absence of detectable bacteria, using culture and molecular microbiology techniques). Amniotic fluid and maternal plasma CHCHD2/MNRR1 concentrations were determined with a validated and sensitive immunoassay.

RESULTS

(1) CHCHD2/MNRR1 was detectable in all amniotic fluid samples and women at term without labor had a higher amniotic fluid CHCHD2/MNRR1 concentration than those in the mid-trimester (p = 0.003); (2) the amniotic fluid concentration of CHCHD2/MNRR1 in women at term in labor was higher than that in women at term without labor (p = 0.01); (3) women with PTL and IAI had a higher amniotic fluid CHCHD2/MNRR1 concentration than those without IAI, either with preterm (p < 0.001) or term delivery (p = 0.01); (4) women with microbial-associated IAI had a higher amniotic fluid CHCHD2/MNRR1 concentration than those with sterile IAI (p < 0.001); (5) among women with PTL and IAI, the amniotic fluid concentration of CHCHD2/MNRR1 correlated with that of interleukin-6 (Spearman's Rho = 0.7; p < 0.001); and (6) no correlation was observed between amniotic fluid and maternal plasma CHCHD2/MNRR1 concentrations among women with PTL.

CONCLUSION

CHCHD2/MNRR1 is a physiological constituent of human amniotic fluid in normal pregnancy, and the amniotic concentration of this mitochondrial protein increases during pregnancy, labor at term, and preterm labor with intra-amniotic infection. Hence, CHCHD2/MNRR1 may be released into the amniotic cavity by dysfunctional mitochondria during microbial-associated IAI.

Chorioamnionitis: An Update on Diagnostic Evaluation

Chorioamnionitis remains a major cause of preterm birth and maternal and neonatal morbidity. We reviewed the current evidence for the diagnostic tests of chorioamnionitis and how this relates to clinical practice today. A comprehensive literature search and review was conducted on chorioamnionitis and intra-uterine inflammation. Data from randomized control trials and systematic reviews were prioritized. This review highlights that sterile inflammation plays an important role in chorioamnionitis and that the current tests for chorioamnionitis including clinical criteria, maternal plasma and vaginal biomarkers lack diagnostic accuracy. Concerningly, these tests often rely on detecting an inflammatory response after damage has occurred to the fetus. Care should be taken when interpreting current investigations for the diagnosis of chorioamnionitis and how they guide obstetric/neonatal management. There is an urgent need for further validation of current diagnostic tests and the development of novel, accurate, minimally invasive tests that detect subclinical intra-uterine inflammation.

Incidence and Prevalence of Vaginal Infections in Women of Reproductive Age in North Macedonia

In the available literature on this subject there are many studies which describe the effects of sexually transmitted infections on pregnancy and fertility of women. Because of the frequency of the infections with the atypical bacteria of the Ureaplasma Spp., Mycoplasma Spp., Chlamydia Trachomatis, as well as HPV infections in women of reproductive age, it is easy to underestimate their importance when establishing the basis of the genital health of women of reproductive age. In this prospective analysis, conducted from 2014 to 2018 in the laboratory for HPV and Molecular diagnostics at the University Clinic of Gynaecology and Obstetrics in Skopje, North Macedonia, we analysed the results of 10,387 patients of all ages, of which 973 patients were of reproductive age. A Panel analysis was also conducted (including the above-mentioned pathogens). An HPV analysis was also conducted on 643 patients in this group. Within the group of 643 patients, there was a positive result for HPV in 26.7% of them, while in 40.9% there was a positive result for one or more pathogens on the Panel analysis of bacterial pathogens. The statistical analysis of the results showed that the most frequent of all bacterial pathogens within the Macedonian population of women of reproductive age is Ureaplasma Spp, with an incidence of 33%, followed by Mycoplasma Spp., with 7.8%, while Chlamydia Trachomatis was present in 6.4% of the cases. We should highlight that a co-infection with HPV was present in 18.5% of all the patients where there was analysis of both diagnostic procedures. The analysis of the results in the patients co-infected with HPV and at least one bacterial pathogen on the Panel Analysis, showed a very high statistical correlation (p<001).

Intra-amniotic inflammation in the mid-trimester of pregnancy is a risk factor for neuropsychological disorders in childhood

OBJECTIVES

Intra-amniotic inflammation is a subclinical condition frequently caused by either microbial invasion of the amniotic cavity or sterile inflammatory stimuli, e.g., alarmins. An accumulating body of evidence supports a role for maternal immune activation in the genesis of fetal neuroinflammation and the occurrence of neurodevelopmental disorders such as cerebral palsy, schizophrenia, and autism. The objective of this study was to determine whether fetal exposure to mid-trimester intra-amniotic inflammation is associated with neurodevelopmental disorders in children eight to 12 years of age.

METHODS

This is a retrospective case-control study comprising 20 children with evidence of prenatal exposure to intra-amniotic inflammation in the mid-trimester and 20 controls matched for gestational age at amniocentesis and at delivery. Amniotic fluid samples were tested for concentrations of interleukin-6 and C-X-C motif chemokine ligand 10, for bacteria by culture and molecular microbiologic methods as well as by polymerase chain reaction for eight viruses. Neuropsychological testing of children, performed by two experienced psychologists, assessed cognitive and behavioral domains. Neuropsychological dysfunction was defined as the presence of an abnormal score (<2 standard deviations) on at least two cognitive tasks.

RESULTS

Neuropsychological dysfunction was present in 45% (9/20) of children exposed to intra-amniotic inflammation but in only 10% (2/20) of those in the control group (p=0.03). The relative risk (RR) of neuropsychological dysfunction conferred by amniotic fluid inflammation remained significant after adjusting for gestational age at delivery [aRR=4.5 (1.07-16.7)]. Of the 11 children diagnosed with neuropsychological dysfunction, nine were delivered at term and eight of them had mothers with intra-amniotic inflammation. Children exposed to intra-amniotic inflammation were found to have abnormalities in neuropsychological tasks evaluating complex skills, e.g., auditory attention, executive functions, and social skills, whereas the domains of reasoning, language, and memory were not affected in the cases and controls.

CONCLUSIONS

Asymptomatic sterile intra-amniotic inflammation in the mid-trimester of pregnancy, followed by a term birth, can still confer to the offspring a substantial risk for neurodevelopmental disorders in childhood. Early recognition and treatment of maternal immune activation in pregnancy may be a strategy for the prevention of subsequent neurodevelopmental disorders in offspring.

Is there a placental microbiota? A critical review and re-analysis of published placental microbiota datasets

The existence of a placental microbiota is debated. The human placenta has historically been considered sterile and microbial colonization was associated with adverse pregnancy outcomes. Yet, recent DNA sequencing investigations reported a microbiota in typical human term placentas. However, this detected microbiota could represent background DNA or delivery-associated contamination. Using fifteen publicly available 16S rRNA gene datasets, existing data were uniformly re-analyzed with DADA2 to maximize comparability. While Amplicon Sequence Variants (ASVs) identified as Lactobacillus, a typical vaginal bacterium, were highly abundant and prevalent across studies, this prevalence disappeared after applying likely  DNA contaminant removal to placentas from term cesarean deliveries. A six-study sub-analysis targeting the 16S rRNA gene V4 hypervariable region demonstrated that bacterial profiles of placental samples and technical controls share principal bacterial ASVs and that placental samples clustered primarily by study origin and mode of delivery. Contemporary DNA-based evidence does not support the existence of a placental microbiota.ImportanceEarly-gestational microbial influences on human development are unclear. By applying DNA sequencing technologies to placental tissue, bacterial DNA signals were observed, leading some to conclude that a live bacterial placental microbiome exists in typical term pregnancy. However, the low-biomass nature of the proposed microbiome and high sensitivity of current DNA sequencing technologies indicate that the signal may alternatively derive from environmental or delivery-associated bacterial DNA contamination. Here we address these alternatives with a re-analysis of 16S rRNA gene sequencing data from 15 publicly available placental datasets. After identical DADA2 pipeline processing of the raw data, subanalyses were performed to control for mode of delivery and environmental DNA contamination. Both environment and mode of delivery profoundly influenced the bacterial DNA signal from term-delivered placentas. Aside from these contamination-associated signals, consistency was lacking across studies. Thus, placentas delivered at term are unlikely to be the original source of observed bacterial DNA signals.

TwinEDA: a sustainable deep-learning approach for limb-position estimation in preterm infants' depth images

Early diagnosis of neurodevelopmental impairments in preterm infants is currently based on the visual analysis of newborns' motion patterns by trained operators. To help automatize this time-consuming and qualitative procedure, we propose a sustainable deep-learning algorithm for accurate limb-pose estimation from depth images. The algorithm consists of a convolutional neural network (TwinEDA) relying on architectural blocks that require limited computation while ensuring high performance in prediction. To ascertain its low computational costs and assess its application in on-the-edge computing, TwinEDA was additionally deployed on a cost-effective single-board computer. The network was validated on a dataset of 27,000 depth video frames collected during the actual clinical practice from 27 preterm infants. When compared to the main state-of-the-art competitor, TwinEDA is twice as fast to predict a single depth frame and four times as light in terms of memory, while performing similarly in terms of Dice similarity coefficient (0.88). This result suggests that the pursuit of efficiency does not imply the detriment of performance. This work is among the first to propose an automatic and sustainable limb-position estimation approach for preterm infants. This represents a significant step towards the development of broadly accessible clinical monitoring applications.

A single-cell atlas of murine reproductive tissues during preterm labor

Preterm birth, the leading cause of perinatal morbidity and mortality worldwide, frequently results from the syndrome of preterm labor. The best-established causal link to preterm labor is intra-amniotic infection, which involves premature activation of the parturition cascade in the reproductive tissues. Herein, we utilize single-cell RNA sequencing (scRNA-seq) to generate a single-cell atlas of the murine uterus, decidua, and cervix in a model of infection-induced preterm labor. We show that preterm labor affects the transcriptomic profiles of specific immune and non-immune cell subsets. Shared and tissue-specific gene expression signatures are identified among affected cells. Determination of intercellular communications implicates specific cell types in preterm labor-associated signaling pathways across tissues. In silico comparison of murine and human uterine cell-cell interactions reveals conserved signaling pathways implicated in labor. Thus, our scRNA-seq data provide insights into the preterm labor-driven cellular landscape and communications in reproductive tissues.

Streptococcus agalactiae npx Is Required for Survival in Human Placental Macrophages and Full Virulence in a Model of Ascending Vaginal Infection during Pregnancy

Streptococcus agalactiae, also known as group B Streptococcus (GBS), is a Gram-positive encapsulated bacterium that colonizes the gastrointestinal tract of 30 to 50% of humans. GBS causes invasive infection during pregnancy that can lead to chorioamnionitis, funisitis, preterm prelabor rupture of membranes (PPROM), preterm birth, neonatal sepsis, and maternal and fetal demise. Upon infecting the host, GBS encounters sentinel innate immune cells, such as macrophages, within reproductive tissues. Once phagocytosed by macrophages, GBS upregulates the expression of the gene npx, which encodes an NADH peroxidase. GBS mutants with an npx deletion (Δnpx) are exquisitely sensitive to reactive oxygen stress. Furthermore, we have shown that npx is required for GBS survival in both THP-1 and placental macrophages. In an in vivo murine model of ascending GBS vaginal infection during pregnancy, npx is required for invading reproductive tissues and is critical for inducing disease progression, including PPROM and preterm birth. Reproductive tissue cytokine production was also significantly diminished in Δnpx mutant-infected animals compared to that in animals infected with wild-type (WT) GBS. Complementation in trans reversed this phenotype, indicating that npx is critical for GBS survival and the initiation of proinflammatory signaling in the gravid host. IMPORTANCE This study sheds new light on the way that group B Streptococcus (GBS) defends itself against oxidative stress in the infected host. The enzyme encoded by the GBS gene npx is an NADH peroxidase that, our study reveals, provides defense against macrophage-derived reactive oxygen stress and facilitates infections of the uterus during pregnancy. This enzyme could represent a tractable target for future treatment strategies against invasive GBS infections.

SARS-CoV-2 infection during pregnancy and preterm birth in Massachusetts from March 2020 through March 2021

BACKGROUND

SARS-CoV-2 infection during pregnancy has been linked to preterm birth, but this association is not well understood.

OBJECTIVES

To examine the association between SARS-CoV-2 infection and spontaneous and provider-initiated preterm birth (PTB), and how timing of infection, and race/ethnicity as a marker of structural inequality, may modify this association.

METHODS

We conducted a retrospective cohort study among pregnant people who delivered singleton, liveborn infants (22-44 weeks gestation) from 1 March 2020 to 31 March 2021 (n = 68,288). We used Cox proportional hazards models to compare the hazard of PTB between pregnant people with and without laboratory-confirmed SARS-CoV-2 infection during pregnancy. We evaluated this association according to the trimester of infection, timing from infection to birth, and timing of PTB. We also examined the joint associations of SARS-CoV-2 infection and race/ethnicity with PTB using the relative excess risk due to interaction (RERI).

RESULTS

Positive SARS-CoV-2 tests were identified for 2195 pregnant people (3.2%). The prevalence of PTB was 7.2% (3.8% spontaneous, 3.6% provider-initiated). SARS-CoV-2 infection during pregnancy was associated with an increased risk of PTB overall (adjusted hazard ratio [HR] 1.53, 95% confidence interval [CI] 1.34, 1.74), and provider-initiated PTB (HR 1.79, 95% CI 1.50, 2.12) but not spontaneous PTB (HR 1.09, 95% CI 0.89, 1.36). Second trimester infections were associated with an increased risk of provider-initiated PTB, and third trimester infections were associated with an increased risk of both PTB subtypes. A joint inverse association between White non-Hispanic race/ethnicity and SARS-CoV-2 infection and spontaneous PTB (HR 0.56, 95% CI 0.34, 0.94; RERI -0.6, 95% CI -1.0, -0.2) was also observed.

CONCLUSIONS

SARS-CoV-2 infections were primarily associated with an increased risk for provider-initiated PTB in this study. These findings highlight the importance of promoting infection-prevention strategies among pregnant people.

Progesterone withdrawal and parturition

The steroid hormone progesterone (P4), acting via the nuclear P4 receptors (PRs) in uterine cells, is essential for the establishment and maintenance of pregnancy. P4/PR signaling maintains pregnancy by promoting uterine quiescence and blocking the contractions of labor. Withdrawal of the P4/PR block to labor induces parturition. The success of pregnancy requires the timely birth of a mature neonate to a healthy mother, and to this end, the mechanism by which the P4/PR block is withdrawn, and how that process is physiologically controlled is critical. This review examines current understanding of cell and molecular biology of P4/PR withdrawal in the control of parturition.

The amniotic fluid proteome predicts imminent preterm delivery in asymptomatic women with a short cervix

Preterm birth, the leading cause of perinatal morbidity and mortality, is associated with increased risk of short- and long-term adverse outcomes. For women identified as at risk for preterm birth attributable to a sonographic short cervix, the determination of imminent delivery is crucial for patient management. The current study aimed to identify amniotic fluid (AF) proteins that could predict imminent delivery in asymptomatic patients with a short cervix. This retrospective cohort study included women enrolled between May 2002 and September 2015 who were diagnosed with a sonographic short cervix (< 25 mm) at 16–32 weeks of gestation. Amniocenteses were performed to exclude intra-amniotic infection; none of the women included had clinical signs of infection or labor at the time of amniocentesis. An aptamer-based multiplex platform was used to profile 1310 AF proteins, and the differential protein abundance between women who delivered within two weeks from amniocentesis, and those who did not, was determined. The analysis included adjustment for quantitative cervical length and control of the false-positive rate at 10%. The area under the receiver operating characteristic curve was calculated to determine whether protein abundance in combination with cervical length improved the prediction of imminent preterm delivery as compared to cervical length alone. Of the 1,310 proteins profiled in AF, 17 were differentially abundant in women destined to deliver within two weeks of amniocentesis independently of the cervical length (adjusted p-value < 0.10). The decreased abundance of SNAP25 and the increased abundance of GPI, PTPN11, OLR1, ENO1, GAPDH, CHI3L1, RETN, CSF3, LCN2, CXCL1, CXCL8, PGLYRP1, LDHB, IL6, MMP8, and PRTN3 were associated with an increased risk of imminent delivery (odds ratio > 1.5 for each). The sensitivity at a 10% false-positive rate for the prediction of imminent delivery by a quantitative cervical length alone was 38%, yet it increased to 79% when combined with the abundance of four AF proteins (CXCL8, SNAP25, PTPN11, and MMP8). Neutrophil-mediated immunity, neutrophil activation, granulocyte activation, myeloid leukocyte activation, and myeloid leukocyte-mediated immunity were biological processes impacted by protein dysregulation in women destined to deliver within two weeks of diagnosis. The combination of AF protein abundance and quantitative cervical length improves prediction of the timing of delivery compared to cervical length alone, among women with a sonographic short cervix.

Clarithromycin prevents preterm birth and neonatal mortality by dampening alarmin-induced maternal–fetal inflammation in mice

Background

One of every four preterm neonates is born to a woman with sterile intra-amniotic inflammation (inflammatory process induced by alarmins); yet, this clinical condition still lacks treatment. Herein, we utilized an established murine model of sterile intra-amniotic inflammation induced by the alarmin high-mobility group box-1 (HMGB1) to evaluate whether treatment with clarithromycin prevents preterm birth and adverse neonatal outcomes by dampening maternal and fetal inflammatory responses.

Methods

Pregnant mice were intra-amniotically injected with HMGB1 under ultrasound guidance and treated with clarithromycin or vehicle control, and pregnancy and neonatal outcomes were recorded (n = 15 dams each). Additionally, amniotic fluid, placenta, uterine decidua, cervix, and fetal tissues were collected prior to preterm birth for determination of the inflammatory status (n = 7–8 dams each).

Results

Clarithromycin extended the gestational length, reduced the rate of preterm birth, and improved neonatal mortality induced by HMGB1. Clarithromycin prevented preterm birth by interfering with the common cascade of parturition as evidenced by dysregulated expression of contractility-associated proteins and inflammatory mediators in the intra-uterine tissues. Notably, clarithromycin improved neonatal survival by dampening inflammation in the placenta as well as in the fetal lung, intestine, liver, and spleen.

Conclusions

Clarithromycin prevents preterm birth and improves neonatal survival in an animal model of sterile intra-amniotic inflammation, demonstrating the potential utility of this macrolide for treating women with this clinical condition, which currently lacks a therapeutic intervention.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12884-022-04764-2.

To evaluate the role of placental human papilloma virus (HPV) infection as a risk factor for spontaneous preterm birth: a prospective case control study

OBJECTIVES

i) To compare the placental human papilloma virus (HPV) deoxynucleic acid (DNA) status of preterm deliveries with full term deliveries and to identify high risk (HR) genotypes (HPV 16 and 18); and ii) To compare the perinatal outcomes of HPV positive with HPV negative pregnant women.

METHODS

A case control study was carried out on 100 antenatal women with singleton live pregnancies admitted in labor ward of a tertiary care teaching hospital from April 2017 to March 2018. The two study groups were i) spontaneous preterm deliveries between 24 and 36 + 6 weeks (n=50) and ii) full term deliveries ≥37 weeks (n=50). The placental tissue was analysed for HPV DNA and HR HPV genotypes were detected by type specific primers. A comparative analysis of perinatal outcomes between HPV positive and negative women was done.

RESULTS

An overall placental tissue HPV prevalence of 12% (12/100) was observed in study cohort which was not significantly different between preterm and full term deliveries (16 vs. 8%, p=0.218). HPV 16 was significantly associated with preterm births (p=0.04). Both HPV affected and non-affected women were comparable in terms of mode of delivery and neonatal outcomes. However, a statistically significant association of preterm neonatal intensive care admissions with HR HPV 16 genotype was observed (p=0.04).

CONCLUSIONS

Spontaneous preterm births can be attributed to placental HPV infection, specifically HR HPV 16 genotype. This association identifies a potentially preventable cause of prematurity and its associated complications, in wake of availability of an effective vaccine.

Periodontal Disease and Adverse Neonatal Outcomes: A Systematic Review and Meta-Analysis

Objective

The aim of this study was to evaluate the association between maternal periodontal disease (PD) and three main adverse neonatal outcomes, namely, preterm birth (PTB), low birth weight (LBW), and small for gestational age (SGA).

Methods

The Ovid Medline, Web of Science, Embase, and Cochrane Library were searched up to 6 December 2020 for relevant observational studies on an association between PD and risk of PTB, LBW, and SGA. Eligibility criteria included observational studies which compared the prevalence of PTB and/or LBW and/or SGA between PD women and periodontal health controls. The exclusion criteria included incomplete data, animal research, and mixing up various pregnancy outcomes, such as "preterm low birth weight" and languages other than Chinese and English. Data were extracted and analyzed independently by two authors. The meta-analysis was performed using Stata Statistical Software, Release 12 (StataCorp LP, College Station, TX, USA). Odds ratio (OR), confidence intervals (CIs), and heterogeneity (I 2) were computed.

Results

Fourteen case-control studies and 10 prospective cohort studies, involving 15,278 participants, were identified. Based on fixed effect meta-analysis, PTB showed a significant association with PD (OR = 1.57, 95% CI: 1.39-1.77, P < 0.00001) and LBW also showed a significant association with PD (OR = 2.43, 95% CI: 1.75-3.37, P < 0.00001) in a random effect meta-analysis. However, a random effect meta-analysis showed no relationship between PD and SGA (OR = 1.62, 95% CI: 0.86-3.07, P = 0.136).

Conclusion

Our findings indicate that pregnant women with PD have a significantly higher risk of PTB and LBW. However, large prospective, blinded cohort studies with standardized diagnostic criteria of PD and adequate control of confounding factors are still required to confirm the relationship between PD and adverse neonatal outcomes.

Foeto-maternal complications associated with low birth weight: A prospective multicenter study in northern Ghana

Objective

The study evaluated the socio-demographic characteristics, obstetric variables and foeto-maternal complications associated with low birth weight (LBW) in order to provide better treatment and management options.

Methods

The prospective study conducted from February, 2019 to June, 2020 recruited 312 primigravid pregnant women who reported for antenatal care in three tertiary referral hospitals in northern Ghana. Their socio-demographic, obstetric and adverse foeto-maternal outcome information were obtained with a well-structured questionnaire according to the World Health Organisation (WHO) guidelines. Participants’ blood samples were collected for haematological tests. Odds ratio [OR, 95% confidence interval (CI)] for the association between socio-demographic, obstetric characteristics, foeto-maternal complications and haematological tests in relation to LBW were assessed using logistic regression model.

Results

This study reported a LBW prevalence of 13.5%. Increasing maternal systolic blood pressure (SBP) and diastolic blood pressure (DBP) at 1st visit, before and after delivery significantly increased the odds of LBW. Preterm delivery (PTD<37 weeks) (COR = 9.92, 95% CI (4.87–2020), p<0.001), preeclampsia (PE) (COR = 5.94, 95% CI (2.96–11.94), p<0.001), blood transfusion (COR = 14.11, 95% CI (2.50–79.65), p = 0.003), caesarian delivery (COR = 3.86, 95% CI (1.96–7.58), p<0.001) and male sex neonates (COR = 2.25, 95%CI (1.14–4.47), P = 0.020) presented with increased odds of LBW. Increasing gestational age at delivery presented with 28% reduced odds of LBW (COR = 0.72, 95% CI (1.12–4.40), P = 0.023). Upon controlling for potential confounders in multivariate logistic regression, only gestational age at delivery (AOR = 0.67, 95% CI (0.47–0.96), P = 0.030) remained significantly associated with reduced odds of LBW.

Conclusion

This study found that high blood pressure at 1st visit, before and after delivery results in increased chances of delivering a baby with LBW. Furthermore, PTD<37 weeks, having PE in current pregnancy, and male sex potentiate the risk of LBW. On the other hand, increasing gestational age reduces the risk of LBW. Thus, we recommend that midwives should intensify education to pregnant women on the benefits of regular ANC visits to aid in the early detection of adverse foeto-maternal complications. We also recommend proper clinical management of pregnancies associated with an elevated blood pressure at registration. Also, maternal intrapartum blood pressure measurement could be used to predict LBW in low resourced settings.

The Maternal–Fetal Gut Microbiota Axis: Physiological Changes, Dietary Influence, and Modulation Possibilities

The prenatal period and the first years of life have a significant impact on the health issues and life quality of an individual. The appropriate development of the immune system and the central nervous system are thought to be major critical determining events. In parallel to these, establishing an early intestinal microbiota community is another important factor for future well-being interfering with prenatal and postnatal developmental processes. This review aims at summarizing the main characteristics of maternal gut microbiota and its possible transmission to the offspring, thereby affecting fetal and/or neonatal development and health. Since maternal dietary factors are potential modulators of the maternal–fetal microbiota axis, we will outline current knowledge on the impact of certain diets, nutritional factors, and nutritional modulators during pregnancy on offspring’s microbiota and health.

Individualized treatment of preterm premature rupture of membranes to prolong the latency period, reduce the rate of preterm birth, and improve neonatal outcomes

BACKGROUND

Preterm premature rupture of membranes complicates approximately 3% of pregnancies. Currently, in the absence of chorioamnionitis or placental abruption, expectant management, including antenatal steroids for lung maturation and prophylactic antibiotic treatment, is recommended. The benefits of individualized management have not been adequately explored.

OBJECTIVE

This study aimed to compare the impact of 2 different management strategies of preterm premature rupture of membranes in 2 tertiary obstetrical centers on latency of >7 days, latency to birth, chorioamnionitis, funisitis, and short-term adverse maternal and neonatal outcomes.

STUDY DESIGN

This was a multicenter retrospective study of women with singleton pregnancies with preterm premature rupture of membranes from 23 0/7 to 33 6/7 weeks of gestation between 2014 and 2018 and undelivered within 24 hours after hospital admission managed at Sunnybrook Health Sciences Center, Toronto, Canada (standard management group), and BCNatal (Hospital Clínic of Barcelona and Hospital Sant Joan de Déu Barcelona), Barcelona, Spain (individualized management group), following local protocols. The standard management group received similar management for all patients, which included a standard antibiotic regimen and routine maternal and fetal surveillance, whereas the individualized management group received personalized management on the basis of amniocentesis at hospital admission (if possible), to rule out microbial invasion of the amniotic cavity and targeted treatment. The exclusion criteria were cervical dilatation >2 cm, active labor, contraindications to expectant management (acute chorioamnionitis, placental abruption, or abnormal fetal tracing), and major fetal anomalies. The primary outcome was latency of >7 days, and the secondary outcomes included latency to birth, chorioamnionitis, and short-term adverse maternal and neonatal outcomes. Statistical comparisons between groups were conducted with propensity score weighting.

RESULTS

A total of 513 pregnancies with preterm premature rupture of membranes were included in this study: 324 patients received standard management, and 189 patients received individualized management, wherein amniocentesis was performed in 112 cases (59.3%). After propensity score weighting, patients receiving individualized management had a higher latency of >7 days (76.0% vs 41.6%; P<.001) and latency to birth (18.1±14.7 vs 9.7±9.7 days; P<.001). Although a higher rate of clinical chorioamnionitis was suspected in the individualized management group than the standard group (34.5% vs 22.0%; P<.01), there was no difference between the groups in terms of histologic chorioamnionitis (67.2% vs 73.4%; P=.16), funisitis (57.6% vs 58.1%; P=.92), or composite infectious maternal outcomes (9.1% vs 7.9%; P=.64). Prolonged latency in the individualized management group was associated with a significant reduction of preterm birth at <32 weeks of gestation (72.1% vs 90.5%; P<.001), neonatal intensive care unit admission (75.6% vs 83.0%; P=.046), and neonatal respiratory support at 28 days of life (16.1% vs 26.1%; P<.01) compared with that in the standard management group. Moreover, prolonged latency was not associated with neonatal severe morbidity at discharge (survival without severe morbidity, 80.4% vs 73.5%; P=.09).

CONCLUSION

Individualized management of preterm premature rupture of membranes may prolong pregnancy and reduce preterm birth at <32 weeks of gestation, the need for neonatal support, and neonatal intensive care unit admissions, without an increase in histologic chorioamnionitis, funisitis, neonatal infection-related morbidity, and short-term adverse maternal and neonatal outcomes.

Periodontal disease and preterm delivery: a nationwide population-based cohort study of Taiwan

Preterm delivery of low-birth weight infants is considered a leading cause of morbidity and mortality among neonates. Various studies have reported a positive correlation between periodontal disease (PD) and premature birth (PB) and yet no population-based study has assessed the impact of PD severity and treatments on premature birth. This cohort study used Taiwan’s national medical records (1999–2012, included 1,757,774 pregnant women) to investigate the association between PD severity and PB. Women with PD during the 2-year period prior for giving birth were more likely to have PB (11.38%) than those without PD (10.56%; p < 0.001). After variables adjustment, the advanced PD group had OR of 1.09 (95% CI 1.07–1.11) for PB, the mild PD group had OR of 1.05 (95% CI 1.04–1.06), while no-PD group had OR of 1. Increased PD severity was related to higher risk of PB. When stratified by age, the highest ORs for PB were those aged from 31 to 35 years in both mild PD group (OR = 1.09, 95% CI 1.07–1.11) and advanced PD group (OR = 1.13, 95% CI 1.09–1.17). Improving periodontal health before or during pregnancy may prevent or reduce the occurrence of adverse pregnancy outcomes and therefore maternal and perinatal morbidity and mortality.

Amniotic LPS-Induced Apoptosis in the Fetal Brain Is Suppressed by Vaginal LPS Preconditioning but Is Promoted by Continuous Ischemic Reperfusion

Chorioamnionitis (CAM) is an increasingly common disease affecting pregnant women which derives from bacterial vaginosis. In different clinical cases, it has been shown that CAM can cause multiple risk factors for fetal brain damage, such as infection, and intra-uterine asphyxia. However, the molecular mechanism remains unknown. In this study, we established a novel CAM mouse model by exposing pregnant mice to a combination of three risk factors: vaginal lipopolysaccharides (LPS), amniotic LPS, and ischemic reperfusion. We found amniotic LPS caused Parkinson's disease-like fetal brain damage, in a dose and time-dependent manner. Moreover, the mechanism of this fetal brain damage is apoptosis induced by amniotic LPS but it was inhibited by being pretreated with a vaginal LPS challenge before amniotic LPS injection. In contrast, amniotic LPS with continuous ischemic reperfusion caused a higher level of apoptotic cell death than amniotic LPS alone. In particular, a potential neuroprotective biomarker phosphorylation (p)-CREB (ser133) appeared in only vaginal LPS preconditioned before amniotic LPS, whereas ischemic reperfusion triggered IKK phosphorylation after amniotic LPS. Despite the need for many future investigations, this study also discussed a developed understanding of the molecular mechanism of how these phenotypes occurred.

Pathologist interobserver variability in diagnosing acute ascending intrauterine infection

The histologic diagnosis of acute ascending intrauterine infection permits a higher-efficacy identification of both subclinical infection and clinical chorioamnionitis, but procedures for placental pathology need to adopt a unified approach and work toward reproducible grading and staging systems. We conducted a retrospective chart review of 696 placental records from single and multiple deliveries between January 2011 and February 2020. Then, we compared original diagnoses with diagnoses based on Redline criteria, which is an internationally recognized system of staging and grading. Of the 696 cases available for review, 255 had complete medical records. Findings showed a strong degree of agreement (90%-100%) between original investigators' histological diagnoses of acute ascending intrauterine infection and a review by researchers using Redline criteria. Although interobserver agreement was good, more education is needed on Redline criteria to avoid missed cases (primarily Stage 1), support protocols for pathologists and obstetricians/gynecologists in determining which cases need to be investigated, and the development of reporting standards for acute ascending intrauterine infection and feedback mechanisms during follow-up.

Placental extracellular vesicles-associated microRNA-519c mediates endotoxin adaptation in pregnancy

BACKGROUND

Pregnancy represents a unique challenge for the maternal-fetal immune interface, requiring a balance between immunosuppression, which is essential for the maintenance of a semiallogeneic fetus, and proinflammatory host defense to protect the maternal-fetal interface from invading organisms. Adaptation to repeated inflammatory stimuli (endotoxin tolerance) may be critical in preventing inflammation-induced preterm birth caused by exaggerated maternal inflammatory responses to mild or moderate infections that are common during pregnancy. However, the exact mechanisms contributing to the maintenance of tolerance to repeated infections are not completely understood. MicroRNAs play important roles in pregnancy with several microRNAs implicated in gestational tissue function and in pathologic pregnancy conditions. MicroRNA-519c, a member of the chromosome 19 microRNA cluster, is a human-specific microRNA mainly expressed in the placenta. However, its role in pregnancy is largely unknown.

OBJECTIVE

This study aimed to explore the role of "endotoxin tolerance" failure in the pathogenesis of an exaggerated inflammatory response often seen in inflammation-mediated preterm birth. In this study, we investigated the role of microRNA-519c, a placenta-specific microRNA, as a key regulator of endotoxin tolerance at the maternal-fetal interface.

STUDY DESIGN

Using a placental explant culture system, samples from term and second-trimester placentas were treated with lipopolysaccharide. After 24 hours, the conditioned media were collected for analysis, and the placental explants were re-exposed to repeated doses of lipopolysaccharide for 3 days. The supernatant was analyzed for inflammatory markers, the presence of extracellular vesicles, and microRNAs. To study the possible mechanism of action of the microRNAs, we evaluated the phosphodiesterase 3B pathway involved in tumor necrosis factor alpha production using a microRNA mimic and phosphodiesterase 3B small interfering RNA transfection. Finally, we analyzed human placental samples from different gestational ages and from women affected by inflammation-associated pregnancies.

RESULTS

Our data showed that repeated exposure of the human placenta to endotoxin challenges induced a tolerant phenotype characterized by decreased tumor necrosis factor alpha and up-regulated interleukin-10 levels. This reaction was mediated by the placenta-specific microRNA-519c packaged within placental extracellular vesicles. Lipopolysaccharide treatment increased the extracellular vesicles that were positive for the exosome tetraspanin markers, namely CD9, CD63, and CD81, and secreted primarily by trophoblasts. Primary human trophoblast cells transfected with a microRNA-519c mimic decreased phosphodiesterase 3B, whereas a lack of phosphodiesterase 3B, achieved by small interfering RNA transfection, led to decreased tumor necrosis factor alpha production. These data support the hypothesis that the anti-inflammatory action of microRNA-519c was mediated by a down-regulation of the phosphodiesterase 3B pathway, leading to inhibition of tumor necrosis factor alpha production. Furthermore, human placentas from normal and inflammation-associated pregnancies demonstrated that a decreased placental microRNA-519c level was linked to infection-induced inflammatory pathologies during pregnancy.

CONCLUSION

We identified microRNA-519c, a human placenta-specific microRNA, as a novel regulator of immune adaptation associated with infection-induced preterm birth at the maternal-fetal interface. Our study serves as a basis for future experiments to explore the potential use of microRNA-519c as a biomarker for infection-induced preterm birth.

Plasma concentrations of leptin at mid-pregnancy are associated with gestational weight gain among pregnant women in Tanzania: a prospective cohort study

Background

Gestational weight gain (GWG) has critical implications for maternal and child health. Inflammation and angiogenesis are implicated in various aspects of maternal metabolism that may play a role in gestational weight gain. The associations of inflammatory, angiogenic, and metabolic pathways with GWG are yet to be elucidated. This study evaluated associations between a panel of inflammatory, angiogenic, and metabolic proteins measured in mid-pregnancy and gestational weight gain.

Methods

Pregnant women were enrolled from Dar es Salaam, Tanzania, between 2001 and 2004. The participants were enrolled at mid-pregnancy (12 to 27 weeks of gestation) and followed up until delivery. This analysis focused on a cohort of 1002 women who were primigravid, had singleton live births, had longitudinal measures of gestational weight, and whose mid-pregnancy plasma samples underwent analysis for 18 proteins.

Results

Higher plasma concentrations of leptin (mean difference in GWG percent adequacy comparing highest with lowest quartiles: 10.24; 95% CI 3.31, 17.16; p-trend = 0.003) and chitinase-3-like protein-1 (CH3L1) (mean difference in GWG percent adequacy comparing highest with lowest quartiles: 7.02; 95% CI 0.31, 13.72; p-trend = 0.007) were associated with greater GWG in a dose-response pattern. Higher leptin concentrations were associated with a lower risk of inadequate GWG (risk ratio comparing highest with lowest quartiles: 0.77; 95% CI 0.65, 0.91; p-trend = 0.001) and a higher risk of excessive GWG (risk ratio comparing highest with lowest quartiles: 1.57; 95% CI 1.03, 2.39; p-trend = 0.03). Higher CH3L1 concentrations were associated with a higher risk of excessive GWG (p-trend = 0.007). The associations of leptin and CH3L1 with inadequate GWG were stronger during the second than the third trimester. The other 16 proteins examined were not significantly associated with GWG.

Conclusions

Mid-pregnancy plasma leptin concentrations may be associated with GWG and have clinical predictive utility in identifying women at a higher risk of inadequate or excessive gestational weight gain.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12884-021-04146-0.

Betamethasone as a potential treatment for preterm birth associated with sterile intra-amniotic inflammation: a murine study

OBJECTIVES

Preterm birth remains the leading cause of perinatal morbidity and mortality worldwide. Preterm birth is preceded by spontaneous preterm labor, which is commonly associated with sterile intra-amniotic inflammation; yet, no approved treatment exists for this clinical condition. Corticosteroids are the standard of care to improve neonatal outcomes in women at risk of preterm birth. Herein, we first validated our model of alarmin-induced preterm birth. Next, we investigated whether treatment with betamethasone could prevent preterm birth resulting from sterile intra-amniotic inflammation in mice.

METHODS

Under ultrasound guidance, the first cohort of dams received an intra-amniotic injection of the alarmin high-mobility group box-1 (HMGB1, n=10) or phosphate-buffered saline (PBS, n=9) as controls. A second cohort of dams received HMGB1 intra-amniotically and were subcutaneously treated with betamethasone (n=15) or vehicle (n=15). Dams were observed until delivery, and perinatal outcomes were observed.

RESULTS

Intra-amniotic HMGB1 reduced gestational length (p=0.04), inducing preterm birth in 40% (4/10) of cases, of which 100% (4/4) were categorized as late preterm births. Importantly, treatment with betamethasone extended the gestational length (p=0.02), thereby reducing the rate of preterm birth by 26.6% (from 33.3% [5/15] to 6.7% [1/15]). Treatment with betamethasone did not worsen the rate of neonatal mortality induced by HMGB1 or alter weight gain in the first three weeks of life.

CONCLUSIONS

Treatment with betamethasone prevents preterm birth induced by the alarmin HMGB1. This study supports the potential utility of betamethasone for treating women with sterile intra-amniotic inflammation.

Using principal component analysis to examine associations of early pregnancy inflammatory biomarker profiles and adverse birth outcomes

OBJECTIVE

Inflammation as a risk factor for preterm birth is well-established. The primary objective of this analysis was to examine whether individual cytokines versus a composite indicator of mid-pregnancy inflammation are significantly associated with risk for adverse birth outcomes.

STUDY DESIGN

A multi-site prospective study was conducted in a socio-demographically diverse cohort of 610 pregnant participants. At a study visit between 12 and 20 6/7 weeks' gestation, low-grade inflammation was measured via log-transformed serum concentrations of the biomarkers IFN-γ, IL-10, IL-13, IL-6, IL-8, TNF-α, and CRP. Principal component analysis (PCA) was used to identify underlying dimensions of inflammatory activity from the seven biomarkers measured. Gestational age and birth weight at delivery were obtained from medical chart review. The associations between inflammatory profiles and birth outcomes were assessed via linear and logistic regression models. Results were compared with those from individual inflammatory biomarkers, and model fit was assessed using Akaike's Information Criterion (AIC).

RESULTS

Principal component analysis analysis yielded a two-factor solution, with the first factor (IF1) composed of IL-8, IL-10, IL-13, IFN-ɣ, and TNF-α, and the second factor (IF2) containing IL-6 and CRP. When adjusted for race, education, BMI, smoking status, gestational age at time of blood draw, and study site, a one standard deviation (SD) increase in IF1 remained significantly associated with a decrease in standardized gestational age (β = -.13, 95% CI: -.21, -.05) and an increase in odds of preterm delivery (OR = 1.46, 95% CI: 1.13, 1.88) (Table 3). A one SD increase in IF2 was similarly associated with a decrease in standardized gestational age at delivery (β = -.13, 95% CI: -.23, -.04) and an increase in odds of preterm delivery (OR: 1.46, 95% CI: 1.04, 2.05). Neither IF1 nor IF2 was associated with measures of fetal growth. AIC identified that IL-6 was a slightly better fit for length of gestation compared to either composite measure, though all performed similarly.

CONCLUSION

Independent of known sociodemographic risk factors, an elevated mid-pregnancy inflammatory profile was associated with a nearly 50% increase in odds of preterm delivery. The composite performed similarly to IL-6. These results suggest that maternal low-grade inflammation is a risk factor for preterm delivery, and that mid-pregnancy inflammatory biomarkers may be useful in predicting risk for preterm delivery.

Understanding Host-Pathogen Interactions in Acute Chorioamnionitis Through the Use of Animal Models

Inflammation of the chorion and/or amnion during pregnancy is called chorioamnionitis. Acute chorioamnionitis is implicated in approximately 40% of preterm births and has wide-ranging implications for the mother, fetus, and newborn. Large disease burden and lack of therapeutic approaches drive the discovery programs to define and test targets to tackle chorioamnionitis. Central to the advancement of these studies is the use of animal models. These models are necessary to deepen our understanding of basic mechanisms of host-pathogen interactions central to chorioamnionitis disease pathogenesis. Models of chorioamnionitis have been developed in numerous species, including mice, rabbits, sheep, and non-human primates. The various models present an array of strategies for initiating an inflammatory response and unique opportunities for studying its downstream consequences for mother, fetus, or newborn. In this review, we present a discussion of the key features of human chorioamnionitis followed by evaluation of currently available animal models in light of these features and consideration of how these models can be best applied to tackle outstanding questions in the field.

Effectiveness of antenatal screening of asymptomatic bacteriuria in reduction of prematurity and low birth weight: Evaluating a point-of-care rapid test in a pragmatic randomized controlled study

BACKGROUND

Premature babies suffer higher mortality and life-long disabilities. Asymptomatic bacteriuria (ASB) is postulated to induce preterm labor. Routine antenatal screening for ASB using urine culture is not feasible in most developing countries due to long turn-around time, user-unfriendliness, and lack of resources. The current parallel-group superiority pragmatic randomized controlled trial evaluated the effect of screening and evidence-based treatment of ASB using an optical-sensor-based point-of-care rapid-test on the incidence of preterm birth and low birthweight (LBW).

METHODS

240 consenting asymptomatic pregnant women visiting an Indian tertiary public hospital for first antenatal check-up, irrespective of trimester/gravida, who had not consumed antibiotics in the preceding week, were enrolled from February-May 2017. Computer-generated concealed simple randomization allocation sequence was used to assign participants to intervention (120) and control arm (120). Usual hospital-care was provided in the control arm. In the intervention arm, urine samples were additionally screened for ASB using the rapid-test and the positive women were prescribed susceptible antibiotics. Blinded outcome assessors followed up with women post-delivery. The study was registered with the Clinical Trials Registry-India (CTRI/2016/09/007240).

FINDINGS

213 participants were analyzed (intervention: 103, control: 110). 21 women were found positive for ASB and prescribed pathogen-specific antibiotics. The incidence of preterm birth/LBW in intervention arm (n = 27) was lower than control arm (n = 45) by 14·7% (95% CI: 2·2-27·2); RR: 0.64, (95% CI: 0·43-0·95); p = 0·023, X2=5·13.

INTERPRETATION

Rapid-test-guided treatment for ASB reduced the incidence of preterm birth/LBW in a pragmatic setting without any adverse event.

FUNDING

Department of Biotechnology, Government of India.

The Short Cervix: A Critical Analysis of Diagnosis and Treatment

A short cervix in the second trimester is a significant risk factor for spontaneous preterm birth, preterm prelabor rupture of membranes, and subsequent adverse perinatal outcome. The pathophysiology is complex and multifactorial with inflammatory and/or infectious processes often involved. Biomarkers have been developed in an effort to predict preterm birth with varying degrees of success. The treatment options of cerclage, progesterone, pessary, and combination therapy are reviewed. Evidence-based protocols are summarized for singleton and multiple gestation.

Magnetic Resonance Imaging Correlates of White Matter Gliosis and Injury in Preterm Fetal Sheep Exposed to Progressive Systemic Inflammation

Progressive fetal infection/inflammation is strongly associated with neural injury after preterm birth. We aimed to test the hypotheses that progressively developing fetal inflammation leads to neuroinflammation and impaired white matter development and that the histopathological changes can be detected using high-field diffusion tensor magnetic resonance imaging (MRI). Chronically instrumented preterm fetal sheep at 0.7 of gestation were randomly assigned to receive intravenous saline (control; n = 6) or a progressive infusion of lipopolysaccharide (LPS, 200 ng intravenous over 24 h then doubled every 24 h for 5 days to induce fetal inflammation, n = 7). Sheep were killed 10 days after starting the infusions, for histology and high-field diffusion tensor MRI. Progressive LPS infusion was associated with increased circulating interleukin (IL)-6 concentrations and moderate increases in carotid artery perfusion and the frequency of electroencephalogram (EEG) activity (p < 0.05 vs. control). In the periventricular white matter, fractional anisotropy (FA) was increased, and orientation dispersion index (ODI) was reduced (p < 0.05 vs. control for both). Histologically, in the same brain region, LPS infusion increased microglial activation and astrocyte numbers and reduced the total number of oligodendrocytes with no change in myelination or numbers of immature/mature oligodendrocytes. Numbers of astrocytes in the periventricular white matter were correlated with increased FA and reduced ODI signal intensities. Astrocyte coherence was associated with increased FA. Moderate astrogliosis, but not loss of total oligodendrocytes, after progressive fetal inflammation can be detected with high-field diffusion tensor MRI.

Maternal periodontal status, oral inflammatory load, and systemic inflammation are associated with low infant birth weight

BACKGROUND

Periodontal disease and pregnancy outcomes have been claimed to be associated with conflicting reports. The purpose of this study was to prospectively examine the association between maternal periodontal status, oral inflammatory load and serum C- reactive protein (CRP) level, and infant birth weight.

METHODS

A total of 156 pregnant women (age 26.62 ± 3.93 years) within the gestational age group of 13 to 32 weeks participated in this cross-sectional study. Oral inflammatory load (OIL) was assessed in a salivary rinse sample using fluorescence microscopy. Clinical periodontal parameters were recorded and serum C-reactive protein level (CRP) was assessed. Participants were followed till delivery, details of parturition and infant birth weight (IBW) was recorded.

RESULTS

OIL was significantly more in participants with mild and moderate periodontitis as compared to those with gingivitis in mid and late stages of pregnancy. Periodontal and systemic inflammatory parameters were positively correlated. A significant negative correlation was found between IBW and OIL (P = 0.006) and serum CRP (P < 0.001). The GI score (P = 0.039), BOP% (P = 0.023), serum CRP level (P < 0.001) and oral polymorphonuclear neutrophil (oPMN) count (P < 0.001) was significantly more in mothers delivering babies with low IBW. A multiple linear regression analysis showed that only oPMN (β = - 0.244, P = 0.021) and serum CRP (β = - 0.226, P = 0.019) were included in the best model (R²  = 0.12, F(3,152) = 7.15, P < 0.001) for significantly predicting the infant birth weight.

CONCLUSIONS

Poor maternal periodontal status, increased oral inflammatory load and increased systemic inflammation have an adverse effect on infant birth weight.

RNA Sequencing Reveals Diverse Functions of Amniotic Fluid Neutrophils and Monocytes/Macrophages in Intra-Amniotic Infection

Intra-amniotic infection, the invasion of microbes into the amniotic cavity resulting in inflammation, is a clinical condition that can lead to adverse pregnancy outcomes for the mother and fetus as well as severe long-term neonatal morbidities. Despite much research focused on the consequences of intra-amniotic infection, there remains little knowledge about the innate immune cells that respond to invading microbes. We performed RNA-seq of sorted amniotic fluid neutrophils and monocytes/macrophages from women with intra-amniotic infection to determine the transcriptomic differences between these innate immune cells. Further, we sought to identify specific transcriptomic pathways that were significantly altered by the maternal or fetal origin of amniotic fluid neutrophils and monocytes/macrophages, the presence of a severe fetal inflammatory response, and pregnancy outcome (i.e., preterm or term delivery). We show that significant transcriptomic differences exist between amniotic fluid neutrophils and monocytes/macrophages from women with intra-amniotic infection, indicating the distinct roles these cells play. The transcriptome of amniotic fluid immune cells varies based on their maternal or fetal origin, and the significant transcriptomic differences between fetal and maternal monocytes/macrophages imply that those of fetal origin exhibit impaired functions. Notably, transcriptomic changes in amniotic fluid monocytes/macrophages suggest that these immune cells collaborate with neutrophils in the trafficking of fetal leukocytes throughout the umbilical cord (i.e., funisitis). Finally, amniotic fluid neutrophils and monocytes/macrophages from preterm deliveries display enhanced transcriptional activity compared to those from term deliveries, highlighting the protective role of these cells during this vulnerable period. Collectively, these findings demonstrate the underlying complexity of local innate immune responses in women with intra-amniotic infection and provide new insights into the functions of neutrophils and monocytes/macrophages in the amniotic cavity.

Cervical stitch (cerclage) in combination with other treatments for preventing spontaneous preterm birth in singleton pregnancies

BACKGROUND

Preterm birth (PTB) remains the foremost global cause of perinatal morbidity and mortality. Thus, the prevention of spontaneous PTB still remains of critical importance. In an attempt to prevent PTB in singleton pregnancies, cervical cerclage, in combination with other treatments, has been advocated. This is because, cervical cerclage is an intervention that is commonly recommended in women with a short cervix at high risk of preterm birth but, despite this, many women still deliver prematurely, as the biological mechanism is incompletely understood. Additionally, previous Cochrane Reviews have been published on the effectiveness of cervical cerclage in singleton and multiple pregnancies, however, none has evaluated the effectiveness of using cervical cerclage in combination with other treatments.

OBJECTIVES

To assess whether antibiotics administration, vaginal pessary, reinforcing or second cerclage placement, tocolytic, progesterone, or other interventions at the time of cervical cerclage placement prolong singleton gestation in women at high risk of pregnancy loss based on prior history and/or ultrasound finding of 'short cervix' and/or physical examination. History-indicated cerclage is defined as a cerclage placed usually between 12 and 15 weeks gestation based solely on poor prior obstetrical history, e.g. multiple second trimester losses due to painless dilatation. Ultrasound-indicated cerclage is defined as a cerclage placed usually between 16 and 23 weeks gestation for transvaginal ultrasound cervical length < 20 mm in a woman without cervical dilatation. Physical exam-indicated cerclage is defined as a cerclage placed usually between 16 and 23 weeks gestation because of cervical dilatation of one or more centimetres detected on physical (manual) examination.

SEARCH METHODS

We searched Cochrane Pregnancy and Childbirth's Trials Register, ClinicalTrials.gov and the WHO International Clinical Trials Registry Platform (ICTRP) (26 September 2019), and reference lists of retrieved studies.

SELECTION CRITERIA

We included published, unpublished or ongoing randomised controlled trial (RCTs). Studies using a cluster-RCT design were also eligible for inclusion in this review but none were identified. We excluded quasi-RCTs (e.g. those randomised by date of birth or hospital number) and studies using a cross-over design. We also excluded studies that specified addition of the combination therapy after cervical cerclage because the woman subsequently became symptomatic. We included studies comparing cervical cerclage in combination with one, two or more interventions with cervical cerclage alone in singleton pregnancies.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened titles and abstracts of all retrieved articles, selected studies for inclusion, extracted data, assessed risk of bias, and evaluated the certainty of the evidence for this review's main outcomes. Data were checked for accuracy. Standard Cochrane review methods were used throughout.

MAIN RESULTS

We identified two studies (involving a total of 73 women) comparing cervical cerclage alone to a different comparator. We also identified three ongoing studies (one investigating vaginal progesterone after cerclage, and two investigating cerclage plus pessary). One study (20 women), conducted in the UK, comparing cervical cerclage in combination with a tocolytic (salbutamol) with cervical cerclage alone in women with singleton pregnancy did not provide any useable data for this review. The other study (involving 53 women, with data from 50 women) took place in the USA and compared cervical cerclage in combination with a tocolytic (indomethacin) and antibiotics (cefazolin or clindamycin) versus cervical cerclage alone - this study did provide useable data for this review (and the study authors also provided additional data on request) but meta-analyses were not possible. This study was generally at a low risk of bias, apart from issues relating to blinding. We downgraded the certainty of evidence for serious risk of bias and imprecision (few participants, few events and wide 95% confidence intervals). Cervical cerclage in combination with an antibiotic and tocolytic versus cervical cerclage alone (one study, 50 women/babies) We are unclear about the effect of cervical cerclage in combination with antibiotics and a tocolytic compared with cervical cerclage alone on the risk of serious neonatal morbidity (RR 0.62, 95% CI 0.31 to 1.24; very low-certainty evidence); perinatal loss (data for miscarriage and stillbirth only - data not available for neonatal death) (RR 0.46, 95% CI 0.13 to 1.64; very low-certainty evidence) or preterm birth < 34 completed weeks of pregnancy (RR 0.78, 95% CI 0.44 to 1.40; very low-certainty evidence). There were no stillbirths (intrauterine death at 24 or more weeks). The trial authors did not report on the numbers of babies discharged home healthy (without obvious pathology) or on the risk of neonatal death.

AUTHORS' CONCLUSIONS

Currently, there is insufficient evidence to evaluate the effect of combining a tocolytic (indomethacin) and antibiotics (cefazolin/clindamycin) with cervical cerclage compared with cervical cerclage alone for preventing spontaneous PTB in women with singleton pregnancies. Future studies should recruit sufficient numbers of women to provide meaningful results and should measure neonatal death and numbers of babies discharged home healthy, as well as other important outcomes listed in this review. We did not identify any studies looking at other treatments in combination with cervical cerclage. Future research needs to focus on the role of other interventions such as vaginal support pessary, reinforcing or second cervical cerclage placement, 17-alpha-hydroxyprogesterone caproate or dydrogesterone or vaginal micronised progesterone, omega-3 long chain polyunsaturated fatty acid supplementation and bed rest.

Detection of microbial cell-free DNA in maternal and umbilical cord plasma in patients with chorioamnionitis using next generation sequencing

Background

Chorioamnionitis has been linked to spontaneous preterm labor and complications such as neonatal sepsis. We hypothesized that microbial cell-free (cf) DNA would be detectable in maternal plasma in patients with chorioamnionitis and could be the basis for a non-invasive method to detect fetal exposure to microorganisms.

Objective

The purpose of this study was to determine whether next generation sequencing could detect microbial cfDNA in maternal plasma in patients with chorioamnionitis.

Study design

Maternal plasma (n = 94) and umbilical cord plasma (n = 120) were collected during delivery at gestational age 28–41 weeks. cfDNA was extracted and sequenced. Umbilical cord plasma samples with evidence of contamination were excluded. The prevalence of microorganisms previously implicated in choriomanionitis, neonatal sepsis and intra-amniotic infections, as described in the literature, were examined to determine if there was enrichment of these microorganisms in this cohort. Specific microbial cfDNA associated with chorioamnionitis was first detected in umbilical cord plasma and confirmed in the matched maternal plasma samples (n = 77 matched pairs) among 14 cases of histologically confirmed chorioamnionitis and one case of clinical chorioamnionitis; 63 paired samples were used as controls. A correlation of rank of a given microorganism across maternal plasma and matched umbilical cord plasma was used to assess whether signals found in umbilical cord plasma were also present in maternal plasma.

Results

Microbial DNA sequences associated with clinical and/or histological chorioamnionitis were enriched in maternal plasma in cases with suspected chorioamnionitis when compared to controls (12/14 microorganisms, p = 0.02). Analysis of the microbial cfDNA in umbilical cord plasma among the 1,251 microorganisms detectable with this assay identified Streptococcus mitis, Ureaplasma spp., and Mycoplasma spp. in cases of suspected chorioamnionitis. This assay also detected cfDNA from Lactobacillus spp. in controls. Comparison between maternal plasma and umbilical cord plasma confirmed these signatures were also present in maternal plasma. Unbiased analysis of microorganisms with significantly correlated signal between matched maternal plasma and umbilical cord plasma identified the above listed 3 microorganisms, all of which have previously been implicated in patients with chorioamnionitis (Mycoplasma hominis p = 0.0001; Ureaplasma parvum p = 0.002; Streptococcus mitis p = 0.007). These data show that the pathogen signal relevant for chorioamnionitis can be identified in both maternal and umbilical cord plasma.

Conclusion

This is the first report showing the detection of relevant microbial cell-free cfDNA in maternal plasma and umbilical cord plasma in patients with clinical and/or histological chorioamnionitis. These results may lead to the development of a specific assay to detect perinatal infections for targeted therapy to reduce early neonatal sepsis complications.

Microbial burden and inflammasome activation in amniotic fluid of patients with preterm prelabor rupture of membranes

Background Intra-amniotic inflammation, which is associated with adverse pregnancy outcomes, can occur in the presence or absence of detectable microorganisms, and involves activation of the inflammasome. Intra-amniotic inflammasome activation has been reported in clinical chorioamnionitis at term and preterm labor with intact membranes, but it has not yet been investigated in women with preterm prelabor rupture of membranes (preterm PROM) in the presence/absence of detectable microorganisms. The aim of this study was to determine whether, among women with preterm PROM, there is an association between detectable microorganisms in amniotic fluid and intra-amniotic inflammation, and whether intra-amniotic inflammasome activation correlates with microbial burden. Methods Amniotic fluids from 59 cases of preterm PROM were examined for the presence/absence of microorganisms through culture and 16S ribosomal RNA (rRNA) gene quantitative real-time polymerase chain reaction (qPCR), and concentrations of interleukin-6 (IL-6) and ASC [apoptosis-associated spec-like protein containing a caspase recruitment domain (CARD)], an indicator of inflammasome activation, were determined. Results qPCR identified more microbe-positive amniotic fluids than culture. Greater than 50% of patients with a negative culture and high IL-6 concentration in amniotic fluid yielded a positive qPCR signal. ASC concentrations were greatest in patients with high qPCR signals and elevated IL-6 concentrations in amniotic fluid (i.e. intra-amniotic infection). ASC concentrations tended to increase in patients without detectable microorganisms but yet with elevated IL-6 concentrations (i.e. sterile intra-amniotic inflammation) compared to those without intra-amniotic inflammation. Conclusion qPCR is a valuable complement to microbiological culture for the detection of microorganisms in the amniotic cavity in women with preterm PROM, and microbial burden is associated with the severity of intra-amniotic inflammatory response, including inflammasome activation.

Preterm labor is characterized by a high abundance of amniotic fluid prostaglandins in patients with intra-amniotic infection or sterile intra-amniotic inflammation

Objective: To distinguish between prostaglandin and prostamide concentrations in the amniotic fluid of women who had an episode of preterm labor with intact membranes through the utilisation of liquid chromatography-tandem mass spectrometry.Study design: Liquid chromatography-tandem mass spectrometry analysis of amniotic fluid of women with preterm labor and (1) subsequent delivery at term (2) preterm delivery without intra-amniotic inflammation; (3) preterm delivery with sterile intra-amniotic inflammation (interleukin (IL)-6>2.6 ng/mL without detectable microorganisms); and (4) preterm delivery with intra-amniotic infection [IL-6>2.6 ng/mL with detectable microorganisms].Results: (1) amniotic fluid concentrations of PGE₂, PGF_2α, and PGFM were higher in patients with intra-amniotic infection than in those without intra-amniotic inflammation; (2) PGE₂ and PGF_2α concentrations were also greater in patients with intra-amniotic infection than in those with sterile intra-amniotic inflammation; (3) patients with sterile intra-amniotic inflammation had higher amniotic fluid concentrations of PGE₂ and PGFM than those without intra-amniotic inflammation who delivered at term; (4) PGFM concentrations were also greater in women with sterile intra-amniotic inflammation than in those without intra-amniotic inflammation who delivered preterm; (5) amniotic fluid concentrations of prostamides (PGE₂-EA and PGF_2α-EA) were not different among patients with preterm labor; (6) amniotic fluid concentrations of prostaglandins, but no prostamides, were higher in cases with intra-amniotic inflammation; and (7) the PGE₂:PGE₂-EA and PGF_2α:PGF_2α-EA ratios were higher in patients with intra-amniotic infection compared to those without inflammation.Conclusions: Mass spectrometric analysis of amniotic fluid indicated that amniotic fluid concentrations of prostaglandins, but no prostamides, were higher in women with preterm labor and intra-amniotic infection than in other patients with an episode of preterm labor. Yet, women with intra-amniotic infection had greater amniotic fluid concentrations of PGE₂ and PGF_2α than those with sterile intra-amniotic inflammation, suggesting that these two clinical conditions may be differentiated by using mass spectrometric analysis of amniotic fluid.

The origin of amniotic fluid monocytes/macrophages in women with intra-amniotic inflammation or infection

Background Monocytes, after neutrophils, are the most abundant white blood cells found in the amniotic cavity of women with intra-amniotic inflammation/infection. However, the origin of such cells has not been fully investigated. Herein, we determined (1) the origin of amniotic fluid monocytes/macrophages from women with intra-amniotic inflammation/infection, (2) the relationship between the origin of amniotic fluid monocytes/macrophages and preterm or term delivery and (3) the localization of monocytes/macrophages in the placental tissues. Methods Amniotic fluid samples (n = 16) were collected from women with suspected intra-amniotic inflammation or infection. Amniotic fluid monocytes/macrophages were purified by fluorescence-activated cell sorting, and DNA fingerprinting was performed. Blinded placental histopathological evaluations were conducted. Immunohistochemistry was performed to detect CD14+ monocytes/macrophages in the placental tissues. Results DNA fingerprinting revealed that (1) 56.25% (9/16) of amniotic fluid samples had mostly fetal monocytes/macrophages, (2) 37.5% (6/16) had predominantly maternal monocytes/macrophages and (3) one sample (6.25% [1/16]) had a mixture of fetal and maternal monocytes/macrophages. (4) Most samples with predominantly fetal monocytes/macrophages were from women who delivered early preterm neonates (77.8% [7/9]), whereas all samples with mostly maternal monocytes/macrophages or a mixture of both were from women who delivered term or late preterm neonates (100% [7/7]). (5) Most of the women included in this study presented acute maternal and fetal inflammatory responses in the placenta (85.7% [12/14]). (6) Women who had mostly fetal monocytes/macrophages in amniotic fluid had abundant CD14+ cells in the umbilical cord and chorionic plate, whereas women with mostly maternal amniotic fluid monocytes/macrophages had abundant CD14+ cells in the chorioamniotic membranes. Conclusion Amniotic fluid monocytes/macrophages can be of either fetal or maternal origin, or a mixture of both, in women with intra-amniotic inflammation or infection. These immune cells could be derived from the fetal and maternal vasculature of the placenta.

Infection-mediated preterm birth: Bacterial origins and avenues for intervention

Preterm birth (PTB) is globally the leading cause of death and disability in children under five years of age. Intra-amniotic infection is well recognised as a major cause of PTB. Importantly, it is the most common cause of extreme PTB (birth prior to 28 weeks gestation), which is frequently associated with a wide range of serious neonatal morbidities. Recent developments in next generation sequencing technologies, combined with many years of culture-based microbiological data have allowed us to gain a deeper understanding of the pathogenesis of infection-mediated PTB. In particular, studies have revealed numerous potential routes to intra-amniotic infection beyond the classically described ascending vaginal route. Currently, antibiotic therapy is standard treatment for suspected or confirmed intra-amniotic infection, although its use in this context has had mixed success due to problems ranging from inappropriate antibiotic selection in relation to the target organism/s, to poor transplacental drug passage. In this review, we will draw together evidence from animal models and human studies to characterise pathways to intra-amniotic infection. We will then thoroughly outline current therapeutic protocols for cases of intra-amniotic infection and suggest potential new avenues for treatment.

Enamel neonatal line thickness in deciduous teeth of Australian children from known maternal health and pregnancy conditions

BACKGROUND

Physiological disruptions to early human development have implications for health and disease in later life. Limited research has explored how prenatal factors influence dental development in children of mothers with known pregnancy conditions. Enamel in human deciduous teeth begins forming in utero and is highly susceptible to physiological upsets experienced perinatally. The moment of birth itself is marked in deciduous enamel by the Neonatal Line (NNL) as a baby transitions from the uterine to external environment. This study evaluates the effect of maternal health factors that include stress and alcohol consumption on NNL in teeth from Australian children.

STUDY DESIGN AND SUBJECTS

Mothers (n = 53) were interviewed about their health during pregnancy and experience of birth. Sixty-five deciduous teeth (incisors, molars, one canine) from their children were donated for histological examination. Neonatal line thickness was measured from thin sections and evaluated against maternal and neonatal factors using statistical analyses, controlling for tooth type and birth number.

RESULTS AND CONCLUSIONS

The only maternal factor of a statistically significant effect on NNL thickness was alcohol consumption. Children of mothers who drank occasionally during pregnancy had a thicker NNL when compared to children of mothers who abstained. These results suggest that maternal lifestyle factors influence NNL formation possibly due to physiological changes that disrupt calcium homeostasis during enamel deposition. We highlight large intra-specific variation in human NNL expression. The potential of dental sampling in identifying children with prenatal exposure to alcohol is suggested.

Fetal T Cell Activation in the Amniotic Cavity during Preterm Labor: A Potential Mechanism for a Subset of Idiopathic Preterm Birth

Prematurity is the leading cause of perinatal morbidity and mortality worldwide. In most cases, preterm birth is preceded by spontaneous preterm labor, a syndrome that is associated with intra-amniotic inflammation, the most studied etiology. However, the remaining etiologies of preterm labor are poorly understood; therefore, most preterm births are categorized as idiopathic. In this study, we provide evidence showing that the fetal immune system undergoes premature activation in women with preterm labor without intra-amniotic inflammation, providing a potential new mechanism of disease for some cases of idiopathic preterm birth. First, we showed that fetal T cells are a predominant leukocyte population in amniotic fluid during preterm gestations. Interestingly, only fetal CD4+ T cells were increased in amniotic fluid of women who underwent idiopathic preterm labor and birth. This increase in fetal CD4+ T cells was accompanied by elevated amniotic fluid concentrations of T cell cytokines such as IL-2, IL-4, and IL-13, which are produced by these cells upon in vitro stimulation, but was not associated with the prototypical cytokine profile observed in women with intra-amniotic inflammation. Also, we found that cord blood T cells, mainly CD4+ T cells, obtained from women with idiopathic preterm labor and birth displayed enhanced ex vivo activation, which is similar to that observed in women with intra-amniotic inflammation. Finally, we showed that the intra-amniotic administration of activated neonatal CD4+ T cells induces preterm birth in mice. Collectively, these findings provide evidence suggesting that fetal T cell activation is implicated in the pathogenesis of idiopathic preterm labor and birth.

Cellular immune responses in amniotic fluid of women with preterm labor and intra-amniotic infection or intra-amniotic inflammation

PROBLEM

Preterm birth is commonly preceded by preterm labor, a syndrome that is causally linked to both intra-amniotic infection and intra-amniotic inflammation. However, the stereotypical cellular immune responses in these two clinical conditions are poorly understood.

METHOD OF STUDY

Amniotic fluid samples (n = 26) were collected from women diagnosed with preterm labor and intra-amniotic infection (amniotic fluid IL-6 concentrations ≥2.6 ng/mL and culturable microorganisms, n = 10) or intra-amniotic inflammation (amniotic fluid IL-6 concentrations ≥2.6 ng/mL without culturable microorganisms, n = 16). Flow cytometry was performed to evaluate the phenotype and number of amniotic fluid leukocytes. Amniotic fluid concentrations of classical pro-inflammatory cytokines, type 1 and type 2 cytokines, and T-cell chemokines were determined using immunoassays.

RESULTS

Women with spontaneous preterm labor and intra-amniotic infection had (a) a greater number of total leukocytes, including neutrophils and monocytes/macrophages, in amniotic fluid; (b) a higher number of total T cells and CD4⁺ T cells, but not CD8⁺ T cells or B cells, in amniotic fluid; and (c) increased amniotic fluid concentrations of IL-6, IL-1β, and IL-10, compared to those with intra-amniotic inflammation. However, no differences in amniotic fluid concentrations of T-cell cytokines and chemokines were observed between these two clinical conditions.

CONCLUSION

The cellular immune responses observed in women with preterm labor and intra-amniotic infection are more severe than in those with intra-amniotic inflammation, and neutrophils, monocytes/macrophages, and CD4⁺ T cells are the main immune cells responding to microorganisms that invade the amniotic cavity. These findings provide insights into the intra-amniotic immune mechanisms underlying the human syndrome of preterm labor.

Antibiotic administration can eradicate intra-amniotic infection or intra-amniotic inflammation in a subset of patients with preterm labor and intact membranes

BACKGROUND

Intra-amniotic infection is present in 10% of patients with an episode of preterm labor, and is a risk factor for impending preterm delivery and neonatal morbidity/mortality. Intra-amniotic inflammation is often associated with intra-amniotic infection, but is sometimes present in the absence of detectable microorganisms. Antibiotic treatment of intra-amniotic infection has traditionally been considered to be ineffective. Intra-amniotic inflammation without microorganisms has a prognosis similar to that of intra-amniotic infection.

OBJECTIVE

To determine whether antibiotics can eradicate intra-amniotic infection or intra-amniotic inflammation in a subset of patients with preterm labor and intact membranes.

MATERIALS AND METHODS

The study population consisted of women who met the following criteria: 1) singleton gestation between 20 and 34 weeks; 2) preterm labor and intact membranes; 3) transabdominal amniocentesis performed for the evaluation of the microbiologic/inflammatory status of the amniotic cavity; 4) intra-amniotic infection and/or intra-amniotic inflammation; and 5) received antibiotic treatment that consisted of ceftriaxone, clarithromycin, and metronidazole. Follow-up amniocentesis was performed in a subset of patients. Amniotic fluid was cultured for aerobic and anaerobic bacteria and genital mycoplasmas, and polymerase chain reaction was performed for Ureaplasma spp. Intra-amniotic infection was defined as a positive amniotic fluid culture or positive polymerase chain reaction, and intra-amniotic inflammation was suspected when there was an elevated amniotic fluid white blood cell count or a positive result of a rapid test for matrix metalloproteinase-8. For this study, the final diagnosis of intra-amniotic inflammation was made by measuring the interleukin-6 concentration in stored amniotic fluid (>2.6 ng/mL). These results were not available to managing clinicians. Treatment success was defined as eradication of intra-amniotic infection and/or intra-amniotic inflammation or delivery ≥37 weeks.

RESULTS

Of 62 patients with intra-amniotic infection and/or intra-amniotic inflammation, 50 received the antibiotic regimen. Of those patients, 29 were undelivered for ≥7 days and 19 underwent a follow-up amniocentesis. Microorganisms were identified by culture or polymerase chain reaction of amniotic fluid obtained at admission in 21% of patients (4/19) who had a follow-up amniocentesis, and were eradicated in 3 of the 4 patients. Resolution of intra-amniotic infection/inflammation was confirmed in 79% of patients (15/19), and 1 other patient delivered at term, although resolution of intra-amniotic inflammation could not be confirmed after a follow-up amniocentesis. Thus, resolution of intra-amniotic inflammation/infection or term delivery (treatment success) occurred in 84% of patients (16/19) who had a follow-up amniocentesis. Treatment success occurred in 32% of patients (16/50) with intra-amniotic infection/inflammation who received antibiotics. The median amniocentesis-to-delivery interval was significantly longer among women who received the combination of antibiotics than among those who did not (11.4 days vs 3.1 days: P = .04).

CONCLUSION

Eradication of intra-amniotic infection/inflammation after treatment with antibiotics was confirmed in 79% of patients with preterm labor, intact membranes, and intra-amniotic infection/inflammation who had a follow-up amniocentesis. Treatment success occurred in 84% of patients who underwent a follow-up amniocentesis and in 32% of women who received the antibiotic regimen.

[Periodontal diseases and complicated pregnancy]

PURPOSE

Based on the datas available in the modern literature, to conduct a study on the effect of dental diseases on the course of pregnancy and outcome; mainly, the impact of periodontal disease on the low birth weight of the newborn and premature birth.

MATERIAL AND METHODS

This article is based on the study of materials from foreign and domestic studies found in the databases Pubmed and Elibrary. Literature data were used for the last 15 years.

RESULTS

The majority of pregnant women who are not receiving due dental examination and suffering with those or other diseases of the oral cavity have an unfavorable outcome of pregnancy, including premature births and low weight of the premature newborn. The role of the chronic effect of oral microorganisms Porphyromonas gingivalis (P. gingivalis) and Fusobacterium nudeatum, as well as local increase in prostaglandin E₂ (PGE₂) and tumor necrosis factor (TNF-α), in the implementation of the inflammatory reaction leading to a decrease in the weight of the fetus by 15-18%.

CONCLUSION

Due to the conducted research it was established that periodontal diseases and other infectious diseases of the oral cavity negatively affect the course of pregnancy and its outcome. The main problems were the lack of women's health education in terms of preparing for pregnancy and sanitation of foci of infection in the oral cavity both before pregnancy and at the time, as well as poor access to the dentist and not receiving proper prevention and, if necessary, treatment of oral diseases.

Quantitative analysis of key periodontopathic bacteria in gestational diabetic and non-diabetic women

Purpose

The aim of this study is to compare the periodontal status and quantify Porphyromonas gingivalis (Pg) and Prevotella intermedia (Pi) from plaque samples of both gestational diabetic mellitus (GDM) and non diabetic pregnant women.

Materials and methods

Sixty first time pregnant women were selected after adjusting for age, duration of pregnancy and educational status. They were then categorized into gestational diabetic women (GDM) (Group A) and healthy pregnant women (non GDM) (Group B). Periodontal examination was done by assessing gingival index, periodontal disease index and probing depth. Microbial analysis on sub-gingival plaque was performed using polymerase chain reaction (PCR). Statistical analysis was done by student t test, chi square test and Fischer exact test.

Results

Group A showed higher gingival index, probing depth and periodontal disease index scores than group B at p < 0.001. Pg was detected in 80% of group A and 40% of group B. Amongst these; it was measured over 2.0 × 10⁴ in 33% of group A, while in the group B it never scored more than 1.0 × 10⁴. While Pi were also detected in 73% of group A women and 40% Group B women but quantification showed Pi > 2.0 × 10⁴ in more number of group A women.

Conclusion

This study showed that there is significant association between the severity of periodontal disease and increased levels of Pg and Pi in gestational diabetic women.

Proof of principle: Physiological transfer of small numbers of bacteria from mother to fetus in late-gestation pregnant sheep

Fetal development is thought to proceed in a sterile environment. Recent reports of the presence of bacterial DNA in human placenta, the transfer of live bacteria from mother to fetus after hypoxia in the pregnant sheep, and the presence of bacteria in the meconium of newborn infants have suggested that the fetus might be exposed to bacteria in utero. The present experiments were designed to test the hypothesis that small numbers of bacteria introduced into the maternal bloodstream (too few to induce fever or changes in maternal food consumption), can be found in the fetus days later. We injected 100 colony forming units of green-, red- and far red- fluorescent protein (GFP, RFP, FRFP) expressing S. aureus into late-gestation pregnant sheep intravenously. Five to 7 days later, the animals were euthanized and tissues collected for analysis of GFP. The inoculations did not cause any fever or other measurable behavioral response in the ewes, but did result in the appearance of GFP DNA, and protein in various tissues within the fetuses. Immunohistochemical analysis reveals GFP protein-containing bacteria that appear to be mostly contained within other cells. We were unable to recover any live GFP-expressing bacteria from the fetal tissues. We conclude that S. aureus, and perhaps other bacteria, gain access to the fetus, although it is not clear from these experiments that they survive in the fetus. It is possible that these low inocula and their progeny were effectively cleared by the fetal immune system.