The immunobiology of preterm labor and birth: intra-amniotic inflammation or breakdown of maternal-fetal homeostasis

Ischemic fallopian tube necrosis with hydatid of Morgagni secondary to post‑caesarean intra‑abdominal adhesions entrapment in the 36th week of pregnancy: A case report and mini‑review of the literature

Surgical adhesions in the pelvis are a well-known complication following cesarean sections. The present study describes a unique case involving acute intra-abdominal inflammation due to ischemic necrosis of the fallopian tube with a hydatid of Morgagni, resulting from entrapment in post-operative adhesions and leading to preterm labor. The patient described herein, a woman in her 36th week of pregnancy with a history of two prior lower-segment cesarean sections, presented with diffuse abdominal pain escalating in intensity and intermittent vomiting. A diagnosis of preterm labor was established, prompting a decision to proceed with cesarean section. The procedure was uneventful, revealing numerous post-operative pelvic adhesions intraoperatively. Further examination revealed ischemic necrosis of the left fallopian tube with a small hydatid of Morgagni, attributed to entrapment due to an adhesion, with no involvement of the left ovary. Upon dissecting the adhesion, tubal perfusion was promptly restored. A decision was made to preserve the affected fallopian tube and perform surgical drainage of the hydatid of Morgagni. Both the mother and newborn were discharged in excellent condition from the clinic on the 4th post-operative day. The case descrbied herein underscores the rarity of preterm labor resulting from ischemic tubal necrosis with a hydatid of Morgagni, secondary to post-cesarean section adhesions. It emphasizes the importance of an intraoperative examination for tubal and ovarian conditions to detect surgical adhesions and underscores the value of preoperative diagnosis and the prevention of post-operative adhesions in pregnant women undergoing cesarean section.

The clinic application of mNGS and ENA-78 assays to identify intra-amniotic infection/inflammation

Objective

The objective of this study is to explore whether metagenomic next-generation sequencing (mNGS) and Epithelial Neutrophil Activating Peptide-78 (ENA-78) assays in the amniotic fluid (AF) of patients with preterm labor (PTL) could be employed for diagnosing intra-amniotic infection/inflammation (IAI/I) and predict the outcomes of emergency cerclage in women with cervical insufficiency(CI).

Methods

AF samples from 40 patients were subjected to PTL were subjected to mNGS and microbial culture to diagnose intra-amniotic infection known as microbial invasion of the amniotic cavity (MIAC); ELISA was used to analyze ENA-78 levels for prediction of intra-amniotic inflammation (IAI). Pregnancy outcomes were compared, the predictive performance of mNGS and ENA-78 were assessed to evaluate the efficacy of emergency cervical cerclage.

Results

The diagnosis rate of MIAC was higher with mNGS (17.5%) compared to microbial culture (2.5%). AF ENA-78 levels were significantly higher in IAI patients than in non-IAI/I patients. ENA-78 demonstrated certain accuracy in identifying IAI, with sensitivity and specificity of 73.3% and 100%, respectively. Compared with non-IAI/I patients, patients with MIAC or IAI exhibited poor pregnancy outcomes after cervical cerclage.

Conclusions

mNGS and ENA-78 assays are valuable means for assessing the state of infection/inflammation in the amniotic cavity and predicting the outcomes of emergency cerclage.

Interleukin-1 Receptor Antagonists Partially Inhibited Histological Injury but Not Tissue Inflammation in a Sheep Model of Pregnancy

Intrauterine inflammation is a significant cause of early preterm birth and fetal injury. There is a lack of effective interventions for intrauterine inflammation. This study aimed to determine whether direct fetal treatment with IL-1 receptor antagonists (IL-1RA), specifically anakinra (competitive IL-1RA) or rytvela (allosteric IL-1RA), could reduce intrauterine inflammation caused by intraamniotic injection of E. coli lipopolysaccharides (LPS) in a sheep model of pregnancy. We hypothesized the fetal intramuscular administration of IL1-RA therapy would comprehensively resolve intrauterine inflammation caused by LPS in the pregnant sheep model. Date-mated Merino ewes carrying single fetuses were randomized into four groups: LPS Group (10 mg intraamniotic LPS injection followed by saline), RYTVELA Group (10 mg LPS injection followed by 5 mg rytvela), ANAKINRA Group (LPS injection followed by 100 mg anakinra), and SALINE Group (saline injection followed by saline). All LPS-exposed fetuses had elevated bilirubin levels, leukopenia, and increased inflammatory mediators IL-1β, IL-8, tumour necrosis factor alpha (TNFα), and monocyte chemoattractant protein 1 (MCP-1) in amniotic fluid and lung tissue. Both anakinra and rytvela treatments reduced immunocyte infiltration in chorioamniotic membranes and lungs, and microglial staining, and increased the oligodendrocyte staining, but did not significantly resolve overall inflammation compared to the SALINE Group. In conclusion, fetal intramuscular administration of anakinra and rytvela did not effectively resolve intrauterine inflammation but showed potential in reducing tissue invasion and brain injury markers. These findings suggest that modest inflammation reduction may protect against brain injury and preterm birth, though no additional benefit was observed compared to intraamniotic IL-1RA treatment.

Oxidative stress-mediated abnormal polarization of decidual macrophages promotes the occurrence of atonic postpartum hemorrhage

Postpartum hemorrhage (PPH) is the leading cause of maternal mortality worldwide. However, the mechanism underlying atonic PPH remains partially elucidated. Multi-omics revealed that differentially expressed proteins and metabolites were enriched in the immune-inflammation pathway in the vaginal blood of patients with atonic PPH. There was a pro-inflammatory immune microenvironment primarily activated by M1 macrophages in the decidua of the patients with atonic PPH, which presented as increased tumor necrosis factor (TNF)-α, interleukin (IL)-6, and IL-8 levels and affected the contraction of the uterine smooth muscle. Besides, the decidual macrophage of the atonic PPH group exhibited increased oxidative stress. The PPH decidual cell culture medium induced the polarization of peripheral blood monocytes towards M1 macrophages while markedly increasing the levels of reactive oxygen species and superoxide anion radical. Using hydrogen peroxide (H2O2) to stimulate decidual macrophages induced a similar polarization state to that in atonic PPH samples, and the secretion of pro-inflammatory cytokines, such as TNF-α and IL-8, was significantly upregulated, which markedly impacted the expression of contraction-associated proteins (CAPs) in the uterine smooth muscle cells (uSMCs). The animal model suggested that H2O2 promoted the polarization of placental macrophages towards M1, affecting the levels of placental oxidative stress and inflammatory infiltration, and the contractility of uterine smooth muscle tissues. In summary, abnormal oxidative stress at the maternal-fetal interface induced the M1 polarization of decidual macrophages, causing the secretion of pro-inflammatory cytokines. TNF-α and IL-8 acted on uSMCs to inhibit CAP expression, inducing atonic PPH.

The maternal-fetal interface at single-cell resolution: uncovering the cellular anatomy of the placenta and decidua

The maternal-fetal interface represents a critical site of immunological interactions that can greatly influence pregnancy outcomes. The unique cellular composition and cell-cell interactions taking place within these tissues has spurred substantial research efforts focused on the maternal-fetal interface. With the recent advent of single-cell technologies, multiple investigators have applied such methods to gain an unprecedented level of insight into maternal-fetal communication. Here, we provide an overview of the dynamic cellular composition and cell-cell communications at the maternal-fetal interface as reported by single-cell investigations. By primarily focusing on data from pregnancies in the second and third trimesters, we aim to showcase how single-cell technologies have bolstered the foundational understanding of each cell's contribution to physiologic gestation. Indeed, single-cell technologies have enabled the examination of classical placental cells, such as the trophoblast, as well as uncovered new roles for structural cells now recognized as active participants in pregnancy and parturition, such as decidual and fetal stromal cells, which are reviewed herein. Furthermore, single-cell data investigating the ontogeny, function, differentiation, and interactions among immune cells present at the maternal-fetal interface, namely macrophages, T cells, dendritic cells, neutrophils, mast cells, innate lymphoid cells, natural killer cells, and B cells are discussed in this review. Moreover, a key output of single-cell investigations is the inference of cell-cell interactions, which has been leveraged to not only dissect the intercellular communications within specific tissues but also between compartments such as the decidua basalis and placental villi. Collectively, this review emphasizes the ways by which single-cell technologies have expanded the understanding of cell composition and cellular processes underlying pregnancy in mid-to-late gestation at the maternal-fetal interface, which can prompt their continued application to reveal new pathways and targets for the treatment of obstetrical disease.

Docosahexaenoic acid (DHA) Supplementation During Pregnancy Reduces the Risk of Preterm Birth in Threatened Preterm Labor. The Multicenter Randomized Controlled Trial

Background

Threatened preterm labor is a common reason for hospital admission, and DHA supplementation may lower the risk of preterm labor.

Objective

To compare the rates of premature birth between individuals with threatened preterm labor who received DHA and those who did not.

Methods

In this multi-center randomized controlled trial, the sample size was calculated to be 60 participants. Pregnant individuals who experienced threatened preterm labor at 24 to 34 weeks gestation were given either 1000 milligrams of DHA daily or no DHA supplement. The criteria for inclusion consisted of singleton pregnancies that had been diagnosed with threatened preterm labor, with no cervical change present. DHA supplementation was initiated when threatened preterm labor was diagnosed and continued until 37 weeks of gestation or until delivery, whichever occurred first. The main outcome was to compare the rates of premature births between the two groups. Moreover, we intended to evaluate the side effects of the DHA supplement along with the outcomes for neonates.

Results

Sixty-one pregnant individuals were enrolled and randomly assigned to two groups. Group 1 consisted of 30 participants, each receiving a daily intake of 1,000 milligrams of DHA supplement. Group 2, comprising 31 individuals, did not receive any supplemental DHA. The rate of preterm birth was 23.33% (7/30) and 25.81% (8/31) for the participant group receiving DHA and not receiving DHA, respectively, with a p-value of 0.82. The rate of low-birth-weight neonates was 13.33% (4/30) and 19.35% (6/31) for the participant group receiving DHA and not receiving DHA, respectively, with a p-value of 0.73. The overall results did not show any statistically significant differences. In addition, the rates of cesarean sections, peripartum infections, early postpartum hemorrhage, and NICU admissions did not show significant differences between the two groups.

Conclusion

Taking DHA supplements after a diagnosis of threatened preterm pregnancy does not decrease the actual rates of early or late preterm births. To reduce the risk of premature birth, DHA should be taken from the beginning of pregnancy, with a recommendation to start in the first trimester. This should ideally start in the second trimester, no later than around 20 weeks of gestation, and should continue until childbirth or approximately 37 weeks of gestation.

Clinical Trial Registration

https://register.clinicaltrials.gov/.

Clinical Trials

gov; ID: NCT06302023.

The Protective Effects of Burdock Fructooligosaccharide on Preterm Labor Through Its Anti-Inflammatory Action

Most pharmacotherapeutic chemicals/interventions used to manage preterm labor (PTL) often cause neonatal morbidity and maternal adverse reactions. Fructooligosaccharides, extracted from traditional Chinese medicine, can alleviate inflammation, demonstrate antiviral capabilities, and protect against antioxidant stress, implying a potential effective PTL treatment. In this study, we explored the protective effects of the purified burdock fructooligosaccharide (BFO), a Gfn-type fructose polymer, on inflammation-induced PTL. It was found that two doses of 30 mg/kg mouse BFO administration to pregnant mice at a 6 h interval can effectively ameliorate lipopolysaccharide (LPS)-induced PTL. Drug dynamic distribution analysis revealed that BFO was rather highly enriched in myometrial tissues, could inhibit oxytocin-induced uterine smooth muscle contraction, and could bind toll-like receptor 4 (TLR4) on the membrane of uterine smooth muscle cells, downregulating the expression of downstream genes, attenuating the upregulation of inflammatory cytokines in serum and the myometrium, as well as reversing the increased macrophage and neutrophil infiltration into the myometrium induced by LPS. It can also interfere with the levels of estrogen and progesterone, alleviating the occurrence of premature birth. These findings collectively suggest that BFO might serve as a promising therapeutic agent for inflammation-related preterm labor to safeguard the health of both the mother and fetus.

The single-cell immune profile throughout gestation and its potential value for identifying women at risk for spontaneous preterm birth

Precisely timed immune adaptations, observed in the maternal circulation, underpin the notion of an immune clock of human pregnancy that supports its successful progression and completion at delivery. This immune clock is divided into three immunological phases, with the first phase starting at the time of conception and implantation, shifting into the second phase that supports homeostasis and tolerance throughout pregnancy, and culminating in the last phase of labor and parturition. Disruptions of this immune clock are reported in pregnancy complications such as spontaneous preterm birth. However, our understanding of the immune clock preceding spontaneous preterm birth remains scattered. In this review, we describe the chronology of maternal immune cell adaptations during healthy pregnancies and highlight its disruption in spontaneous preterm birth. With a focus on single-cell cytometric, proteomic and transcriptomic approaches, we review recent studies of term and spontaneous preterm pregnancies and discuss the need for future prospective studies aimed at tracking pregnancies longitudinally on a multi-omic scale. Such studies will be critical in determining whether spontaneous preterm pregnancies progress at an accelerated pace or follow a preterm-intrinsic pattern when compared to those delivered at term.

The rapid diagnosis of intraamniotic infection with nanopore sequencing

BACKGROUND

Intraamniotic infection (defined as intraamniotic inflammation with microorganisms) is an important cause of the preterm labor syndrome. Methods for the detection of microorganisms in amniotic fluid are culture and/or polymerase chain reaction assay. However, both methods take time, and the results are rarely available for clinical decision-making. Nanopore sequencing technology offers real-time, long-read sequencing that can produce rapid results.

OBJECTIVE

To determine 1) the diagnostic performance of the 16S rDNA nanopore sequencing method for the identification of microorganisms in patients with intraamniotic inflammation and 2) the relationship between microbial burden and the intensity of the amniotic fluid inflammatory response.

STUDY DESIGN

We performed a prospective cohort study that included singleton pregnancies presenting with symptoms of preterm labor with intact membranes or of preterm prelabor rupture of the membranes. Amniotic fluid samples were obtained for the evaluation of bacteria in the amniotic cavity using cultivation and polymerase chain reaction-based 16S Sanger sequencing methods. Participants were classified into 4 groups according to the results of an amniotic fluid culture, 16S Sanger sequencing, and an amniotic fluid interleukin 6 concentration: 1) no intraamniotic infection and intraamniotic inflammation (interleukin 6 <2.6 ng/mL, and no microorganisms in the amniotic cavity, as determined by culture or 16S Sanger sequencing); 2) microbial invasion of the amniotic cavity without intraamniotic inflammation, defined by the presence of bacteria detected by culture or 16S Sanger sequencing; 3) sterile intraamniotic inflammation (interleukin 6 ≥2.6 ng/mL without microbial invasion of the amniotic cavity); and 4) intraamniotic infection (interkeukin 6 ≥2.6 ng/mL with microbial invasion of the amniotic cavity). Patients who underwent a mid-trimester amniocentesis, had no intraamniotic infection or intraamniotic inflammation, and delivered at term represented the control group. 16S rDNA nanopore sequencing was performed and the diagnostic indices for the identification of intraamniotic infection were determined. Bioinformatic analysis was carried out to identify microorganisms, and a read count of at least 100 or a read count exceeding that of the background species from the control group, along with a relative abundance of no less than 1%, was used.

RESULTS

1) The 16S nanopore sequencing had a sensitivity of 88.9% (8/9), specificity of 95.4% (41/43), positive predictive value of 80.0% (8/10), negative predictive value of 97.6% (41/42), positive likelihood ratio of 19.1 (95% confidence interval, 4.8-75.4), negative likelihood ratio of 0.1 (95% confidence interval, 0.02-0.7), and an accuracy of 94.2% (49/52) for the identification of intraamniotic infection (prevalence, 17% [9/52]); 2) the microbial load determined by the 16S nanopore sequencing had a strong positive correlation with the intensity of an intraamniotic inflammatory response (amniotic fluid interleukin 6 concentration; Spearman's correlation 0.9; P=.002); and 3) a subgroup of patients with intraamniotic inflammation did not have bacteria determined by culture, Sanger sequencing, or nanopore 16S, thus confirming the existence of sterile intraamniotic inflammation.

CONCLUSION

The 16S nanopore sequencing has high diagnostic indices, predictive values, likelihood ratios, and accuracy in the diagnosis of intraamniotic infection.

Assessment of the thymus in fetuses prior to spontaneous preterm birth using functional MRI

OBJECTIVES

The aim of this study was to utilise T2* relaxometry (an indirect method of quantifying tissue oxygenation) to assess the fetal thymus in uncomplicated pregnancies throughout gestation and in a cohort of fetuses that subsequently deliver very preterm.

METHODS

A control group of participants with low-risk pregnancies were recruited and retrospectively excluded if they developed any pregnancy related complications after scanning. Participants were recruited who were deemed to be at very high risk of delivery prior to 32 weeks' gestation and retrospectively excluded if they did not deliver prior to this gestation. All participants underwent a fetal MRI scan on a 3 T system incorporating the fetal thorax. T2 and T2* data were aligned and the mean T2* of the thymus tissue determined.

RESULTS

Mean thymus T2* decreased with gestation in control fetuses (n = 49). In fetuses who went on to deliver prior to 32 weeks' gestation (n = 15), thymus volume was reduced as was mean T2* (p ≤ 0.001) as compared to controls. This finding persisted in a subgroup analysis of participants with PPROM (p = 0.002), although not in those with intact membranes (p = 0.067).

CONCLUSION

These data demonstrates both a likely reduction in perfusion of the thymuses prior to extreme preterm birth, and also the potential for advanced MRI techniques to better interrogate the fetal immune changes prior to preterm birth in vivo.

Maternal and fetal outcomes of autoimmune hepatitis in pregnancy: A United States hospitalized patient study

BACKGROUND

Autoimmune hepatitis (AIH) is a chronic inflammatory disease primarily affecting the liver, with a higher prevalence among women of reproductive age. The latest nationwide statistics regarding its impact on maternal and fetal outcomes during pregnancy are lacking.

AIMS

To analyze the real impact of AIH on maternal and fetal outcomes in hospitalized delivery patients, and provide theoretical guidance for comprehensive clinical management.

METHODS

A retrospective analysis was conducted using data from the 2016-2020 National Inpatient Sample database in the United States. Multivariate logistic regression analysis was used to assess the influence of AIH on maternal and fetal outcomes during pregnancy.

RESULTS

A total of 17,825,445 hospitalized delivery patients were included, among which 1,185 had AIH. After adjusting for potential confounding factors, compared to hospitalized delivery patients without AIH, the AIH group exhibited significantly higher rates of adverse maternal and fetal outcomes, including hypertension complications of pregnancy (AOR 1.68, 95 % CI 1.09-2.58), preterm birth (AOR 2.89, 95 % CI 1.91-4.38), fetal growth restriction (AOR 2.21, 95 % CI 1.34-3.64), and fetal death (AOR 4.13, 95 % CI 1.33-12.83). AIH showed no association with cesarean section or large fetus. In the group of delivery in patients with AIH, patients who develop hypertensive disorders have a higher probability of concomitant diabetes mellitus (OR 6.85, 95 % CI 2.19-21.45), hypertension (OR 4.64, 95 % CI 1.68-12.82), and obesity (OR 3.06, 95 % CI 1.26-7.42). Additionally, AIH patients incurred higher total costs and longer hospital stays during the delivery hospitalization.

CONCLUSION

Patients with AIH face an increased risk of hypertensive disorders of pregnancy, preterm birth, fetal growth restriction, and fetal death during delivery. It is crucial to enhance awareness of these potential occurrence risks.

Macrophages: a double-edged sword in female reproduction and disorders

Reproduction consists of sequential inflammation-like events, primarily within the endometrium, from ovulation to embryo implantation, decidualization and delivery. During the reproductive cycle, the endometrium repeatedly undergoes cyclic periods of proliferation, differentiation, tissue breakdown and repair without scarring. Owing to their phagocytic activity, macrophages, key players in innate immunity, are thought to play crucial roles in the endometrium. Endometrial macrophages actively participate in various stages of reproductive tissue remodeling, particularly during decidualization and pregnancy establishment. Traditionally considered simple bystanders that clear debris to prevent autoimmune responses in tissue homeostasis, macrophages are now recognized as main actors with broad functional plasticity that allows them to fine tune the balance between pro- and anti-inflammatory responses during tissue inflammation, remodeling and repair. Homeostatic balance is determined by the sum of various mediators produced by two distinctly polarized macrophage subpopulations. The biased polarization of tissue-resident macrophages may contribute to the pathogenesis of various diseases, such as inflammation and cancer. Thus, understanding how macrophages contribute to endometrial homeostasis is crucial for deciphering the underlying mechanisms of various reproductive disorders. Nanomedicines using extracellular vesicles, nanoparticles and noncoding RNAs have recently been applied to modulate macrophage polarization and alleviate disease phenotypes. Despite these advances, the functions of endometrial macrophages under physiological and pathophysiological conditions remain poorly understood, which complicates the development of targeted therapies. Here we update the current understanding of the homeostatic function of macrophages and the putative contribution of endometrial macrophage dysfunction to reproductive disorders in women, along with innovative molecular therapeutics to resolve this issue.

The Impact of BMI on PCOS Patients and Transcriptome Profiling and Bioinformatic Analysis of Granulosa Cells in PCOS Patients with High and Low BMI

PURPOSE

To explore the impact of high body mass index (BMI) on the embryo quality and clinical outcomes of polycystic ovary syndrome (PCOS) patients, and the possible genes involved.

METHODS

Patients who underwent in-vitro fertilization (IVF) treatment and embryo transfer in our center from November 2014 to September 2023, were divided into low BMI PCOS (LBP) group, high BMI PCOS (HBP) group, and high BMI control (HBC) group. Transcriptome sequencing was performed in eight PCOS patients' granulosa cells (GCs).

RESULTS

A total of 812 IVF/intracytoplasmic sperm injection (ICSI) cycles in the embryo part; and 489 fresh, 634 frozen-warmed embryo transfer (FET) cycles from the clinical part were included. The ICSI normal fertilization rate of HBP group was decreased compared to LBP and HBC groups (p = 0.013&0.008). The IVF blastocyst development rate in HBP group was lower than LBP group (p = 0.01). The preterm birth rate in HBP group was higher than in LBP (30.66% vs. 16.48%, p = 0.041) and HBC groups (30.66% vs. 11.34%, p = 0.002), the adjusted OR (AOR) of preterm birth and BMI was 1.124 (p = 0.023) in FET cycles. Transcriptome sequencing result of GCs showed that differentially expressed miRNAs/lncRNA/circRNA/mRNAs in two PCOS groups were 61, 450, 83, and 568, respectively. The hub genes analysis, enrichment analysis and competing endogenous RNA network revealed that cell cycle, oocyte maturation, systemic lupus erythematosus, oxidative phosphorylation, and mitogen-activated protein kinases (MAPK) signaling pathways had important roles in the embryo development and pregnancy process.

CONCLUSIONS

The combined effect of PCOS and obesity reduced oocyte quality and embryonic development potential, finally led to poorer clinical outcomes.

Uterine first-pass effect: Unlocking the potential of vaginally administered ritodrine-loaded thermosensitive gel for uterine drug delivery

Preterm birth (PTB) remains a leading cause of infant mortality and morbidity, significantly affecting the long-term health, welfare, and development of newborns. Tocolytics, such as ritodrine, a β2-adrenergic receptor agonist, are widely used in developing countries due to their affordability for preventing PTB by inhibiting uterine contractions. However, ritodrine's short half-life necessitates frequent administration, and prolonged high-dose usage often leads to serious maternal side effects, prompting discontinuation. The uterine first-pass effect, where vaginally administered drugs preferentially target the uterus, can enhance drug concentration in uterine tissue while minimizing systemic absorption and side effects. This study designed a kind of ritodrine-loaded thermosensitive gel (Gel@Rit) to intervene in PTB by exploiting the uterine first-pass effect and investigate its underlying mechanisms. The gel, formulated with poloxamer, demonstrated excellent temperature sensitivity and viscosity, ensuring sustained ritodrine release in vitro. Plasma pharmacokinetic and tissue distribution studies in pregnant mice confirmed the uterine first-pass effect, showing significantly higher drug concentrations in the uterus and markedly lower plasma levels following Gel@Rit administration. The distinctive drug-time curve in Gel@Rit-treated mice, along with uterine tissue fluorescence profiles, elucidated four mechanisms of uterine localization: diffusion through reproductive tract cavities, penetration via vaginal and uterine structures, diffusion through systemic circulation, and retrograde transvaginal veno-uterine artery exchange. This study provides valuable insights into vaginal drug delivery research methodologies, advancing therapeutic strategies for uterine-related conditions and benefiting clinical outcomes in PTB prevention.

Association between cellular immune and preeclampsia and preterm birth: A Mendelian randomization study

Emerging evidences have highlighted immune-inflammatory imbalances as a critical driver of the pathogenesis for preeclampsia (PE) and preterm birth (PB), but the impact of specific immune factors on the diseases is largely unknown. Our aim was to determine whether these immune cells are causally associated with the onset of PE or PB. Drawing on publicly available genetic data, we applied Mendelian randomization analysis to probe the causal link of 731 immune traits (7 panels: TBNK panel, Regulatory T cells panel, Maturation stages of T-cell panel, Dendritic cell panel, B-cell panel, Monocyte panel and Myeloid cell pane) with the risk of PE and PB. The inverse variance weighting method (IVW) acted as the primary analysis to estimate the validity of causality, and sensitivity analyses were conducted to assessment of heterogeneity and pleiotropy. After adjusting for P-values for FDR method, CD27 on CD24+ CD27+ B cell, CD80 on plasmacytoid Dendritic Cell, CD33+ HLA DR+ CD14dim Absolute Count, CD33+ HLA DR+ CD14- Absolute Count, CD33+ HLA DR+ Absolute Count were remarkably causally involved in increased risk of PE, while HLA DR on Dendritic Cell exerted a protective causation against PE (PFDR < 0.05). Moreover, we determined that CD45 on CD33dim HLA DR- in myeloid cells decreased PB risk, whereas CD11b on Granulocytic Myeloid-Derived Suppressor Cells had the opposite effect on PB (FFDR < 0.2). This study provided genetic evidence for causal relationships between immune cell traits and PE and PB, offering potential candidate immunophenotypes for future studies on the etiology of pregnancy complications.

Homeostatic Macrophages Prevent Preterm Birth and Improve Neonatal Outcomes by Mitigating In Utero Sterile Inflammation in Mice

Preterm birth (PTB), often preceded by preterm labor, is a major cause of neonatal morbidity and mortality worldwide. Most PTB cases involve intra-amniotic inflammation without detectable microorganisms, termed in utero sterile inflammation, for which there is no established treatment. In this study, we propose homeostatic macrophages to prevent PTB and adverse neonatal outcomes caused by in utero sterile inflammation. Single-cell atlases of the maternal-fetal interface revealed that homeostatic maternal macrophages are reduced with human labor. M2 macrophage treatment prevented PTB and reduced adverse neonatal outcomes in mice with in utero sterile inflammation. Specifically, M2 macrophages halted premature labor by suppressing inflammatory responses in the amniotic cavity, including inflammasome activation, and mitigated placental and offspring lung inflammation. Moreover, M2 macrophages boosted gut inflammation in neonates and improved their ability to fight systemic bacterial infections. Our findings show that M2 macrophages are a promising strategy to mitigate PTB and improve neonatal outcomes resulting from in utero sterile inflammation.

The role of the RHOA/ROCK pathway in the regulation of myometrial stages throughout pregnancy

Background

Controlling uterine contractile activity is essential to regulate the duration of pregnancy. During most of the pregnancy, the uterus does not contract (i.e., myometrial quiescence). The myometrium recovers its contractile phenotype at around 36 weeks (i.e., myometrial activation) through several mechanisms. The RHOA/ROCK pathway plays a vital role in facilitating muscular contractions by calcium sensitization in humans. Yet, the role of this pathway during different myometrial stages, including quiescence, has not been elucidated.

Objective

we aimed to study the role of the RHOA/ROCK pathway in the regulation of the different myometrial stages throughout pregnancy. Specifically, we hypothesized that the inhibition of the components of the RHOA/ROCK pathway play an important role in maintaining uterine quiescence.

Study design

Myometrial samples were obtained from pregnant individuals who underwent cesarean section. Pregnant individuals who delivered preterm without labor (myometrial quiescence), preterm with labor (nonphysiological myometrial stimulation), term not in labor (activation), and term in labor (physiological myometrial stimulation) were included. The mRNA and protein expression of RHOA, ROCK I, ROCK II, RND1-3, and ROCK activity through pMYTP1 were evaluated.

Results

We found that the human myometrium constitutively expressed RHOA/ROCK pathway components throughout pregnancy. No changes in the components of the RHOA/ROCK pathway were found during quiescence. Moreover, the RHOA protein and ROCK activity increased in the myometrium during labor, supporting the hypothesis that this pathway participates in maintaining the contractile activity of the myometrium. This study provides insight into the role of the RHOA/ROCK pathway in controlling myometrial contractile activity during pregnancy.

A Controlled, Retrospective, Single-Center Study to Evaluate the Role of a Probiotic Mixture Administered during Pregnancy in Reducing Streptococcus Agalactiae Swab Positivity and the Frequency of Premature Rupture of Amniochorionic Membranes

Intrapartum antibiotic prophylaxis, considered able to prevent streptococcal transmission from mother to newborn and its severe negative consequences, leads to microbiota dysbiosis, described as having a negative impact on well-being in both elements of the dyad. Enterococcus faecium L3 is a probiotic strain capable of exerting strong antagonistic activity against most streptococci, including S. agalactiae, due to the production of bacteriocins (known as enterocins A and B). A proprietary probiotic mixture containing the strain L3 demonstrated, in 2016, a significant reduction in episodes of PROM in pregnant women, with a less-than-expected effect on the vaginal-rectal presence of the pathogen S. agalactiae. With the aim of confirming the role exerted by the probiotic mixture in PROM episodes and to better understand the value of its impact on the clinical detection of S. agalactiae, we have retrospectively analyzed the results obtained in 125 L3-treated (over 12 weeks) women versus 125 untreated controls. Despite some limitations, our analysis has confirmed the role exerted by the probiotic in significantly reducing the following: (1) episodes of PROM, (2) vaginal-rectal positivity for S. agalactiae, and (3) the need to administer intrapartum antibiotics for prophylaxis. It likely also suggests operating using a cultural method very specific to S. agalactiae when testing women who were administered an Enterococcus-based probiotic.

Metabolic Perturbations Associated with both PFAS Exposure and Perinatal/Antenatal Depression in Pregnant Individuals: A Meet-in-the-Middle Scoping Review

PURPOSE OF REVIEW

Depression during the perinatal or antenatal period affects at least 1 in 10 women worldwide, with long term health implications for the mother and child. Concurrently, there is increasing evidence associating maternal exposure to per- and poly-fluoroalkyl substances (PFAS) to adverse pregnancy outcomes. We reviewed the body of evidence examining both the associations between PFAS exposure and perturbations in the maternal metabolome, and the associations between the maternal metabolome and perinatal/antenatal depression. Through this, we sought to explore existing evidence of the perinatal metabolome as a potential mediation pathway linking PFAS exposure and perinatal/antenatal depression.

RECENT FINDINGS

There are few studies examining the metabolomics of PFAS exposure-specifically in pregnant women-and the metabolomics of perinatal/antenatal depression, let alone studies examining both simultaneously. Of the studies reviewed (N = 11), the majority were cross sectional, based outside of the US, and conducted on largely homogenous populations. Our review identified 23 metabolic pathways in the perinatal metabolome common to both PFAS exposure and perinatal/antenatal depression. Future studies may consider findings from our review to conduct literature-derived hypothesis testing focusing on fatty acid metabolism, alanine metabolism, glutamate metabolism, and tyrosine metabolism when exploring the biochemical mechanisms conferring the risk of perinatal/antenatal depression due to PFAS exposure. We recommend that researchers also utilize heterogenous populations, longitudinal study designs, and mediation approaches to elucidate key pathways linking PFAS exposures to perinatal/antenatal depression.

New therapeutic target NCF1-directed multi-bioactive conjugate therapies prevent preterm birth and adverse pregnancy outcomes

Preterm birth (PTB) is a leading cause of neonatal morbidity and mortality worldwide, yet the cellular and molecular mechanisms driving this condition remain undeciphered, thus limiting discovery of new therapies. In-depth analyses of human and mouse tissues associated with PTB, in combination with cellular studies, indicated that aberrantly high-expressed neutrophil cytoplasmic factor (NCF) 1 leads to oxidative distress, recruitment, and pro-inflammatory activation of neutrophils and macrophages, while sequentially overexpressed pro-inflammatory mediators induce contractions of uterine smooth muscle cells (USMCs) as well as apoptosis of USMCs and amniotic epithelial cells, thereby causing PTB. According to these new findings, we rationally engineered an amphiphilic macromolecular conjugate LPA by covalently integrating low-molecular-weight heparin, a reactive oxygen species-responsive/scavenging component, and an anti-inflammatory peptide. This bioengineered macromolecular conjugate can self-assemble into multi-bioactive nanoparticles (LPA NP). In a mouse model of PTB, LPA NP effectively delayed PTB and inhibited adverse pregnancy outcomes, by regulating NCF1-mediated oxidative-inflammatory cascades, i.e., attenuating oxidative stress, inhibiting inflammatory cell activation, reducing local inflammation, and decreasing contraction/apoptosis of myometrial cells. Packaging LPA NP into temperature-responsive, self-healing, and bioadhesive hydrogel further potentiated its in vivo efficacies after intravaginal delivery, by prolonging retention time, sustaining nanotherapy release, and increasing bioavailability in the placenta/uterus. Importantly, both the conjugate/nanotherapy and hydrogel formulations exhibited excellent safety profiles in pregnant mice, with negligible side effects on the mother and offspring.

Chemokine and cytokine profiles in preterm and term labor, in preterm prelabor rupture of the membranes, and in normal pregnancy

The objective of this study was to investigate the immune mechanisms involved in preterm labor (PTL), preterm prelabor rupture of the membranes (PPROM), and normal pregnancies. The second objective was to explore immune profiles in PTL for association with early ( < 34 gestational weeks (gw)) or instant ( < 48 h) delivery. This prospective observational multi-center study included women with singleton pregnancies with PTL (n = 80) or PPROM (n = 40) before 34 gw, women with normal pregnancies scheduled for antenatal visits (n = 44), and women with normal pregnancies in active labor at term (n = 40). Plasma samples obtained at admission were analyzed for cytokine and chemokine quantification using a multiplex bead assay in order to compare the immune profiles between PTL, PPROM, and normal pregnancies. In PTL, CXCL1 and CCL17 were significantly higher compared to gestational age-matched women at antenatal visits, whereas for PPROM, CXCL1 and IL-6 were increased. Women in term labor had a more pronounced inflammatory pattern with higher levels of CXCL1, CXCL8, and IL-6 compared with PTL (p = 0.007, 0.003, and 0.013, respectively), as well as higher levels of CCL17, CXCL1 and IL-6 (all p < 0.001) compared with the women at antenatal visits. In PTL, CXCL8 was higher in women with delivery before 34 gw, whereas CXCL8, GM-CSF, and IL-6 were significantly higher in women with delivery within 48 h. To conclude, PTL and PPROM were associated with a complex pattern of inflammation, both involving Th17 (CXCL1) responses. Although further studies are needed, CXCL8, GM-CSF, and IL-6 may be potential candidates for predicting preterm birth in PTL.

Inflammatory mechanisms of preterm labor and emerging anti-inflammatory interventions

Preterm birth is a major public health concern, requiring a deeper understanding of its underlying inflammatory mechanisms and to develop effective therapeutic strategies. This review explores the complex interaction between inflammation and preterm labor, highlighting the pivotal role of the dysregulation of inflammation in triggering premature delivery. The immunological environment of pregnancy, characterized by a fragile balance of immune tolerance and resistance, is disrupted in preterm labor, leading to a pathological inflammatory response. Feto-maternal infections, among other pro-inflammatory stimuli, trigger the activation of toll-like receptors and the production of pro-inflammatory mediators, promoting uterine contractility and cervical ripening. Emerging anti-inflammatory therapeutics offer promising approaches for the prevention of preterm birth by targeting key inflammatory pathways. From TLR-4 antagonists to chemokine and interleukin receptor antagonists, these interventions aim to modulate the inflammatory environment and prevent adverse pregnancy outcomes. In conclusion, a comprehensive understanding of the inflammatory mechanisms leading to preterm labor is crucial for the development of targeted interventions in hope of reducing the incidence of preterm birth and improving neonatal health outcomes.

Docosahexaenoic Acid (DHA) and Eicosapentaenoic Acid (EPA)-Should They Be Mandatory Supplements in Pregnancy?

Docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) are essential fatty acids for the human body. Seafood and microalgae are the most important sources of omega-3 fatty acids. Supplementation with 200 mg/day of DHA during pregnancy and breastfeeding has been suggested for women and infants in countries with low seafood consumption. Maternal concentration of DHA and EPA was associated with concentration in cord blood and breast milk. High concentrations of DHA and EPA were identified at the level of retinal photoreceptors and neuronal cell membranes. It was observed that supplementation with DHA and EPA during pregnancy had beneficial effects on the neurological development of the fetus and infant by improving language, memory, attention, and hand coordination, affecting sleep patterns, and improving visual acuity. Beneficial effects on the development of the infant were also associated with the maternal intake of omega-3 fatty acids during breastfeeding. Supplementation with DHA and EPA may reduce the risk of preterm birth but also of preeclampsia in low-risk pregnancies. Women of childbearing age should have an intake of 250 mg/day of DHA + EPA from their diet or supplements. To reduce the risk of premature birth, pregnant women must additionally receive at least 100-200 mg of DHA every day. It is recommended that supplementation with omega-3 fatty acids starts before 20 weeks of pregnancy. Beneficial effects on the mother have been identified, such as the reduction of postpartum depression symptoms, the decrease of cardiovascular risk, and the anti-inflammatory role.

The vaginal immunoproteome for the prediction of spontaneous preterm birth: A retrospective longitudinal study

Background

Preterm birth is the leading cause of neonatal morbidity and mortality worldwide. Most cases of preterm birth occur spontaneously and result from preterm labor with intact (spontaneous preterm labor [sPTL]) or ruptured (preterm prelabor rupture of membranes [PPROM]) membranes. The prediction of spontaneous preterm birth (sPTB) remains underpowered due to its syndromic nature and the dearth of independent analyses of the vaginal host immune response. Thus, we conducted the largest longitudinal investigation targeting vaginal immune mediators, referred to herein as the immunoproteome, in a population at high risk for sPTB.

Methods

Vaginal swabs were collected across gestation from pregnant women who ultimately underwent term birth, sPTL, or PPROM. Cytokines, chemokines, growth factors, and antimicrobial peptides in the samples were quantified via specific and sensitive immunoassays. Predictive models were constructed from immune mediator concentrations.

Results

Throughout uncomplicated gestation, the vaginal immunoproteome harbors a cytokine network with a homeostatic profile. Yet, the vaginal immunoproteome is skewed toward a pro-inflammatory state in pregnant women who ultimately experience sPTL and PPROM. Such an inflammatory profile includes increased monocyte chemoattractants, cytokines indicative of macrophage and T-cell activation, and reduced antimicrobial proteins/peptides. The vaginal immunoproteome has improved predictive value over maternal characteristics alone for identifying women at risk for early (<34 weeks) sPTB.

Conclusions

The vaginal immunoproteome undergoes homeostatic changes throughout gestation and deviations from this shift are associated with sPTB. Furthermore, the vaginal immunoproteome can be leveraged as a potential biomarker for early sPTB, a subset of sPTB associated with extremely adverse neonatal outcomes.

Funding

This research was conducted by the Perinatology Research Branch, Division of Obstetrics and Maternal-Fetal Medicine, Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, U.S. Department of Health and Human Services (NICHD/NIH/DHHS) under contract HHSN275201300006C. ALT, KRT, and NGL were supported by the Wayne State University Perinatal Initiative in Maternal, Perinatal and Child Health.

The Fetal Spleen in Low-Risk Pregnancies and prior to Preterm Birth: Observational Study of the Role of Anatomical and Functional Magnetic Resonance Imaging

INTRODUCTION

Spontaneous preterm birth complicates ∼7% of pregnancies and causes morbidity and mortality. Although infection is a common etiology, our understanding of the fetal immune system in vivo is limited. This study aimed to utilize T2-weighted imaging and T2* relaxometry (which is a proxy of tissue oxygenation) of the fetal spleen in uncomplicated pregnancies and in fetuses that were subsequently delivered spontaneously prior to 32 weeks.

METHODS

Women underwent imaging including T2-weighted fetal body images and multi-eco gradient echo single-shot echo planar sequences on a Phillips Achieva 3T system. Previously described postprocessing techniques were applied to obtain T2- and T2*-weighted imaging of the fetal spleen and T2-weighted fetal body volumes.

RESULTS

Among 55 women with uncomplicated pregnancies, an increase in fetal splenic volume, splenic:body volume, and a decrease in splenic T2* signal intensity was demonstrated across gestation. Compared to controls, fetuses who were subsequently delivered prior to 32 weeks' gestation (n = 19) had a larger spleen when controlled for the overall size of the fetus (p = 0.027), but T2* was consistent (p = 0.76).

CONCLUSION

These findings provide evidence of a replicable method of studying the fetal immune system and give novel results on the impact of impending preterm birth on the spleen. While T2* decreases prior to preterm birth in other organs, preservation demonstrated here suggests preferential sparing of the spleen.

Ethics of Predicting and Preventing Preterm Birth

Preterm birth (PTB) occurs disproportionately among women who are minoritized and who live and work in poverty. This disadvantage occurs as a result of societal norms and policies that affect how people are treated and determine their access to a broad range of resources. Research that takes social context into account offers the best opportunity for identifying approaches to prevent PTB. The experience and knowledge of women from groups experiencing high rates of PTB can provide important insights for research design and for determining the feasibility and acceptability of potential interventions.

Predicting Spontaneous Preterm Birth Using the Immunome

Throughout pregnancy, the maternal peripheral circulation contains valuable information reflecting pregnancy progression, detectable as tightly regulated immune dynamics. Local immune processes at the maternal-fetal interface and other reproductive and non-reproductive tissues are likely to be the pacemakers for this peripheral immune "clock." This cellular immune status of pregnancy can be leveraged for the early risk assessment and prediction of spontaneous preterm birth (sPTB). Systems immunology approaches to sPTB subtypes and cross-tissue (local and peripheral) interactions, as well as integration of multiple biological data modalities promise to improve our understanding of preterm birth pathobiology and identify potential clinically actionable biomarkers.

Palmitate and group B Streptococcus synergistically and differentially induce IL-1β from human gestational membranes

Introduction

Rupture of the gestational membranes often precedes major pregnancy complications, including preterm labor and preterm birth. One major cause of inflammation in the gestational membranes, chorioamnionitis (CAM) is often a result of bacterial infection. The commensal bacterium Streptococcus agalactiae, or Group B Streptococcus (GBS) is a leading infectious cause of CAM. Obesity is on the rise worldwide and roughly 1 in 4 pregnancy complications is related to obesity, and individuals with obesity are also more likely to be colonized by GBS. The gestational membranes are comprised of several distinct cell layers which are, from outermost to innermost: maternally-derived decidual stromal cells (DSCs), fetal cytotrophoblasts (CTBs), fetal mesenchymal cells, and fetal amnion epithelial cells (AECs). In addition, the gestational membranes have several immune cell populations; macrophages are the most common phagocyte. Here we characterize the effects of palmitate, the most common long-chain saturated fatty acid, on the inflammatory response of each layer of the gestational membranes when infected with GBS, using human cell lines and primary human tissue.

Results

Palmitate itself slightly but significantly augments GBS proliferation. Palmitate and GBS co-stimulation synergized to induce many inflammatory proteins and cytokines, particularly IL-1β and matrix metalloproteinase 9 from DSCs, CTBs, and macrophages, but not from AECs. Many of these findings are recapitulated when treating cells with palmitate and a TLR2 or TLR4 agonist, suggesting broad applicability of palmitate-pathogen synergy. Co-culture of macrophages with DSCs or CTBs, upon co-stimulation with GBS and palmitate, resulted in increased inflammatory responses, contrary to previous work in the absence of palmitate. In whole gestational membrane biopsies, the amnion layer appeared to dampen immune responses from the DSC and CTB layers (the choriodecidua) to GBS and palmitate co-stimulation. Addition of the monounsaturated fatty acid oleate, the most abundant monounsaturated fatty acid in circulation, dampened the proinflammatory effect of palmitate.

Discussion

These studies reveal a complex interplay between the immunological response of the distinct layers of the gestational membrane to GBS infection and that such responses can be altered by exposure to long-chain saturated fatty acids. These data provide insight into how metabolic syndromes such as obesity might contribute to an increased risk for GBS disease during pregnancy.

Clinical risk factors for preterm birth and evaluating maternal psychology in the postpartum period

BACKGROUND

Although the specific pathogenesis of preterm birth (PTB) has not been thoroughly clarified, it is known to be related to various factors, such as pregnancy complications, maternal socioeconomic factors, lifestyle habits, reproductive history, environmental and psychological factors, prenatal care, and nutritional status. PTB has serious implications for newborns and families and is associated with high mortality and complications. Therefore, the prediction of PTB risk can facilitate early intervention and reduce its resultant adverse consequences.

AIM

To analyze the risk factors for PTB to establish a PTB risk prediction model and to assess postpartum anxiety and depression in mothers.

METHODS

A retrospective analysis of 648 consecutive parturients who delivered at Shenzhen Bao'an District Songgang People's Hospital between January 2019 and January 2022 was performed. According to the diagnostic criteria for premature infants, the parturients were divided into a PTB group (n = 60) and a full-term (FT) group (n = 588). Puerperae were assessed by the Self-rating Anxiety Scale (SAS) and Self-rating Depression Scale (SDS), based on which the mothers with anxiety and depression symptoms were screened for further analysis. The factors affecting PTB were analyzed by univariate analysis, and the related risk factors were identified by logistic regression.

RESULTS

According to univariate analysis, the PTB group was older than the FT group, with a smaller weight change and greater proportions of women who underwent artificial insemination and had gestational diabetes mellitus (P < 0.05). In addition, greater proportions of women with reproductive tract infections and greater white blood cell (WBC) counts (P < 0.05), shorter cervical lengths in the second trimester and lower neutrophil percentages (P < 0.001) were detected in the PTB group than in the FT group. The PTB group exhibited higher postpartum SAS and SDS scores than did the FT group (P < 0.0001), with a higher number of mothers experiencing anxiety and depression (P < 0.001). Multivariate logistic regression analysis revealed that a greater maternal weight change, the presence of gestational diabetes mellitus, a shorter cervical length in the second trimester, a greater WBC count, and the presence of maternal anxiety and depression were risk factors for PTB (P < 0.01). Moreover, the risk score of the FT group was lower than that of the PTB group, and the area under the curve of the risk score for predicting PTB was greater than 0.9.

CONCLUSION

This study highlights the complex interplay between postpartum anxiety and PTB, where maternal anxiety may be a potential risk factor for PTB, with PTB potentially increasing the incidence of postpartum anxiety in mothers. In addition, a greater maternal weight change, the presence of gestational diabetes mellitus, a shorter cervical length, a greater WBC count, and postpartum anxiety and depression were identified as risk factors for PTB.

Cross-Sectional Associations between Prenatal Per- and Poly-Fluoroalkyl Substances and Bioactive Lipids in Three Environmental Influences on Child Health Outcomes (ECHO) Cohorts

Prenatal per- and poly-fluoroalkyl substances (PFAS) exposure may influence gestational outcomes through bioactive lipids─metabolic and inflammation pathway indicators. We estimated associations between prenatal PFAS exposure and bioactive lipids, measuring 12 serum PFAS and 50 plasma bioactive lipids in 414 pregnant women (median 17.4 weeks' gestation) from three Environmental influences on Child Health Outcomes Program cohorts. Pairwise association estimates across cohorts were obtained through linear mixed models and meta-analysis, adjusting the former for false discovery rates. Associations between the PFAS mixture and bioactive lipids were estimated using quantile g-computation. Pairwise analyses revealed bioactive lipid levels associated with PFDeA, PFNA, PFOA, and PFUdA (p < 0.05) across three enzymatic pathways (cyclooxygenase, cytochrome p450, lipoxygenase) in at least one combined cohort analysis, and PFOA and PFUdA (q < 0.2) in one linear mixed model. The strongest signature revealed doubling in PFOA corresponding with PGD2 (cyclooxygenase pathway; +24.3%, 95% CI: 7.3-43.9%) in the combined cohort. Mixture analysis revealed nine positive associations across all pathways with the PFAS mixture, the strongest signature indicating a quartile increase in the PFAS mixture associated with PGD2 (+34%, 95% CI: 8-66%), primarily driven by PFOS. Bioactive lipids emerged as prenatal PFAS exposure biomarkers, deepening insights into PFAS' influence on pregnancy outcomes.

Association between maternal and fetal inflammatory biomarkers and offspring weight and BMI during the first year of life in pregnancies with GDM: MySweetheart study

Background

Gestational Diabetes Mellitus (GDM) is frequently associated with chronic, low-grade inflammation. Whether this environment affects offspring anthropometry during early childhood remains to be elucidated. The aim of this study was to investigate the associations between maternal and fetal (cord blood-umbilical artery) inflammatory biomarkers and offspring weight and BMI up to 1 year in pregnancies with GDM.

Methods

In this prospective secondary analysis of the MySweetheart study, we included 193 women with GDM and their offspring. Maternal and fetal (N=39) predictors included serum levels of inflammatory biomarkers including CRP, IL-6, and TNF-α at 24-32 weeks of gestational age (GA) and in the cord blood. Offspring outcomes were small and large for gestational age (SGA, LGA), sex- and age-adjusted weight, and BMI at birth and at 1 year. Univariate and multivariate regression models were performed. Associations were adjusted for maternal pre-pregnancy BMI, age, and ethnicity.

Results

Mean maternal age was 33.6 ± 4.8 years, and pre-pregnancy BMI 25.9 ± 5.6 kg/m2. Their mean gestational age at the 1st GDM visit was 29 ± 2.4 weeks. Gestational age at delivery was 39.7 ± 1.1 weeks, with a mean birthweight of 3.4 ± 0.46 kg; 11.8% of offspring were LGA and 10.8% were SGA. At 1 year of age, mean offspring weight was 9.8 ± 1.2 kg and BMI z-score 0.23 ± 1.1 kg/m2. In the models including only maternal predictors, TNF-α at 24-32 weeks of GA was positively associated with SGA and inversely with offspring weight and BMI at birth and at 1 year (p ≤0.034). In the models including only fetal predictors and the combined model, CRP was inversely associated with BMI at 1 year (p ≤0.020).

Conclusions

In women with GDM, maternal and fetal inflammatory biomarkers distinctively influenced offspring anthropometry during the first year of life, independent of maternal age, prepregnancy BMI and ethnicity. These results suggest that low-grade inflammation during pregnancy may affect the developing offspring by leading to a decrease in weight and BMI and may have implications for future personalized follow-up of women with GDM and their offspring.

Obstructive Sleep Apnea in Pregnancy: A Comprehensive Review of Maternal and Fetal Implications

Obstructive sleep apnea (OSA) is a prevalent yet underdiagnosed condition in pregnancy, associated with various maternal and fetal complications. This review synthesizes the current evidence on the epidemiology, pathophysiology, and neurological consequences of OSA in pregnancy, along with the potential management strategies. Articles were sourced from the PubMed, EMBASE, and Cochrane databases until 2023. Our comprehensive review highlights that the incidence of OSA increases during pregnancy due to physiological changes such as weight gain and hormonal fluctuations. OSA in pregnancy is linked with gestational hypertension, pre-eclampsia, gestational diabetes, and potential adverse fetal outcomes such as intrauterine growth restriction and preterm birth. Continuous positive airway pressure (CPAP) therapy remains the most effective management strategy for pregnant women with OSA. However, adherence to CPAP therapy is often suboptimal. This comprehensive review underscores the importance of the early recognition, timely diagnosis, and effective management of OSA in pregnancy to improve both maternal and fetal outcomes. Future research should focus on enhancing screening strategies and improving adherence to CPAP therapy in this population.

Anaphylaxis-induced premature uterine contractions: a case report and literature review

BACKGROUND

Preterm labor is caused by multiple etiologies, including intra-amniotic infection and/or intra-amniotic inflammation, vascular disorders, cervical disease, decidual senescence, and breakdown of maternal-fetal tolerance. Accumulating evidence in vivo and in vitro has shown that an allergic reaction, including anaphylaxis, can induce preterm uterine contractions. This report describes a case of a pregnant woman who developed anaphylaxis and regular uterine contractions after the ingestion of a strawberry-coated biscuit. We also review the mechanism of allergic reaction (hypersensitivity)-induced preterm labor. Case presentation A 31-year-old woman (gravida 1, para 0) at 30+2 weeks of gestation was admitted to the labor and delivery unit with regular uterine contractions and anaphylactic symptoms after she ingested a strawberry-coated biscuit as a snack. The uterine contractions resolved after the treatment of anaphylaxis by administering antihistamines and epinephrine. The patient subsequently delivered at 39+3 weeks of gestation. The amniotic fluid profile showed no infection or inflammation. A postpartum skin-prick test confirmed a positive type 1 hypersensitivity reaction to the strawberry-coated biscuit.

CONCLUSIONS

We report a case of anaphylaxis-induced uterine contractility in which uterine contractions subsided after the treatment of anaphylaxis. The absence of intra-amniotic infection and/or intra-amniotic inflammation and the cause of the anaphylaxis were confirmed. Our findings indicate that maternal allergic reactions may be one of the mechanisms of preterm labor.

Risk of adverse perinatal outcomes among women with clinical and subclinical histopathological chorioamnionitis

Introduction

Histologic chorioamnionitis (HCA) is a placental inflammatory condition associated with adverse perinatal outcomes (APOs). This historical cohort study explores the risk of APOs in pregnant women with HCA and compares the impact of clinical chorioamnionitis (CCA) with subclinical chorioamnionitis (SCCA).

Methodology

Placentas were evaluated by a perinatal pathologist tand all women with HCA were included. Two groups were integrated: (1) women with clinical chorioamnionitis (CCA) and (2) women with subclinical chorioamnionitis (SCCA). Additionally, we conducted a secondary analysis to compare the prevalence of APOs among stage 1, 2 and 3 of HCA and the risk of APOs between grades 1 and 2 of HCA. The APOs analyzed were preterm birth, stillbirth, neonatal weight < 1,500 g, neonatal sepsis. Relative risk with 95% confidence interval was calculated.

Results

The study included 41 cases of CCA and 270 cases of SCCA. The mean gestational age at diagnosis and birth was 30.2 ± 5.4 weeks and 32.5 ± 5.1 weeks, for group 1 and 2, respectively. The study also found that women with HCA stage 3 and grade 2 had a higher prevalence and risk of adverse perinatal outcomes.

Discussion

The findings of this study suggest the importance of placental histological study to excluded SCCA, which represents a significant risk to both maternal and neonatal health, contributing to high morbidity and mortality.

Transcriptomic analysis delineates preterm prelabor rupture of membranes from preterm labor in preterm fetal membranes

BACKGROUND

Globally, preterm birth remains the leading cause of death in children younger than 5 years old. Spontaneous preterm birth is comprised of two events that may or may not occur simultaneously: preterm labor and preterm prelabor rupture of membranes (PPROM). To further explore the concept that spontaneous preterm birth can result from the initializing of two separate but overlapping pathological events, we compared fetal membrane tissue from preterm labor deliveries to fetal tissue from preterm labor with PPROM deliveries. We hypothesized that the fetal membrane tissue from preterm labor with PPROM cases will have an RNA-seq profile divergent from the fetal membrane tissue from preterm labor controls.

METHODS

Chorioamnion, separated into amnion and chorion, was collected from eight gestationally age-matched cases and controls within 15 min of birth, and analyzed using RNA sequencing. Pathway enrichment analyses and functional annotations of differentially expressed genes were performed using KEGG and Gene Ontogeny Pathway enrichment analyses.

RESULTS

A total of 1466 genes were differentially expressed in the amnion, and 484 genes were differentially expressed in the chorion (log2 fold change > 1, FDR < 0.05) in cases (preterm labor with PPROM), versus controls (preterm labor only). In the amnion, the most significantly enriched (FDR < 0.01) KEGG pathway among down-regulated genes was the extracellular matrix receptor interaction pathway. Seven of the most significantly enriched pathways were comprised of multiple genes from the COL family, including COL1A, COL3A1, COL4A4, and COL4A6. In the chorion, the most significantly enriched KEGG pathways in up-regulated genes were chemokine, NOD receptor, Toll-like receptor, and cytokine-cytokine receptor signaling pathways. Similarly, KEGG pathway enrichment analysis for up-regulated genes in the amnion included three inflammatory pathways: cytokine-cytokine interaction, TNF signaling and the CXCL family. Six genes were significantly up regulated in chorionic tissue discriminated between cases (preterm labor with PPROM) and controls (preterm labor only) including GBP5, CXCL9, ALPL, S100A8, CASP5 and MMP25.

CONCLUSIONS

In our study, transcriptome analysis of preterm fetal membranes revealed distinct differentially expressed genes for PPROM, separate from preterm labor. This study is the first to report transcriptome data that reflects the individual pathophysiology of amnion and chorion tissue from PPROM deliveries.

Analysis of gastric fluid in preterm newborns supports the view that the amniotic cavity is sterile before the onset of parturition: a retrospective cohort study

OBJECTIVES

To compare the frequency of Ureaplasma-positive gastric fluid (GF) cultures based on the cause and mode of delivery in preterm newborns.

METHODS

This retrospective cohort study included women with a singleton pregnancy who delivered prematurely (between 23+0 and 32+0 weeks of gestation, n=464) at a single university hospital in South Korea. The newborns' GF was obtained on the day of birth via nasogastric intubation. The frequency of Ureaplasma spp. in GF cultures was measured and compared according to the cause and mode of delivery.

RESULTS

Ureaplasma spp. was detected in 20.3 % of the GF samples. The presence of Ureaplasma spp. was significantly higher in the spontaneous preterm birth group than in the indicated preterm birth group (30.2 vs. 3.0 %; p<0.001). Additionally, Ureaplasma spp. was more frequently found in the vaginal delivery group than in the cesarean delivery group, irrespective of the cause of preterm delivery [indicated preterm birth group (22.2 vs. 1.9 %, p=0.023); spontaneous preterm birth group (37.7 vs. 24.2 %, p=0.015)].

CONCLUSIONS

Ureaplasma spp. were found in 20.3 % of the GFs. However, only 1.9 % of newborns in the indicated preterm birth group with cesarean delivery had a Ureaplasma-positive GF culture.

CD8+ T cells in fetal membranes display a unique phenotype, and their activation is involved in the pathophysiology of spontaneous preterm birth

Preterm labor/birth is the leading cause of perinatal mortality and morbidity worldwide. Previous studies demonstrated that T cells were crucial for maintaining maternal-fetal immune tolerance during the first trimester of pregnancy; however, their phenotypes and functions in labor and delivery remain largely unknown. We recruited three cohorts of women at delivery for T-cell immunophenotyping in the placentas, fetal membranes, umbilical cord blood, and maternal peripheral blood. Our data showed a differential enrichment of T cells during the third trimester of human pregnancy, with CD4+ T cells being more observable within the umbilical cord blood, whereas CD8+ T cells became relatively more abundant in fetal membranes. CD4+ and CD8+ T cells derived from fetal membranes were dominated by effector memory T cells and exhibited extensive expression of activation markers but decreased expression of homing receptor. In comparison with term births, fetal membrane CD8+ T cells, especially the central memory subset, were significantly increased in frequency and showed more profound activation in spontaneous preterm birth patients. Finally, using an allogeneic mouse model, we found that T-cell-activation-induced preterm birth could be alleviated by the depletion of CD8+ T but not CD4+ T cells in vivo. Collectively, we showed that CD8+ T cells in fetal membranes displayed a unique phenotype, and their activation was involved in the pathophysiology of spontaneous preterm birth, which provides novel insights into the immune mechanisms of preterm birth and potential targets for the prevention of this syndrome. © 2023 The Pathological Society of Great Britain and Ireland.

Omega-3 fatty acid supply in pregnancy for risk reduction of preterm and early preterm birth

This clinical practice guideline on the supply of the omega-3 docosahexaenoic acid and eicosapentaenoic acid in pregnant women for risk reduction of preterm birth and early preterm birth was developed with support from several medical-scientific organizations, and is based on a review of the available strong evidence from randomized clinical trials and a formal consensus process. We concluded the following. Women of childbearing age should obtain a supply of at least 250 mg/d of docosahexaenoic+eicosapentaenoic acid from diet or supplements, and in pregnancy an additional intake of ≥100 to 200 mg/d of docosahexaenoic acid. Pregnant women with a low docosahexaenoic acid intake and/or low docosahexaenoic acid blood levels have an increased risk of preterm birth and early preterm birth. Thus, they should receive a supply of approximately 600 to 1000 mg/d of docosahexaenoic+eicosapentaenoic acid, or docosahexaenoic acid alone, given that this dosage showed significant reduction of preterm birth and early preterm birth in randomized controlled trials. This additional supply should preferably begin in the second trimester of pregnancy (not later than approximately 20 weeks' gestation) and continue until approximately 37 weeks' gestation or until childbirth if before 37 weeks' gestation. Identification of women with inadequate omega-3 supply is achievable by a set of standardized questions on intake. Docosahexaenoic acid measurement from blood is another option to identify women with low status, but further standardization of laboratory methods and appropriate cutoff values is needed. Information on how to achieve an appropriate intake of docosahexaenoic acid or docosahexaenoic+eicosapentaenoic acid for women of childbearing age and pregnant women should be provided to women and their partners.

Parental genetically predicted liability for coronary heart disease and risk of adverse pregnancy outcomes: a cohort study

BACKGROUND

Adverse pregnancy outcomes (APO) may unmask or exacerbate a woman's underlying risk for coronary heart disease (CHD). We estimated associations of maternal and paternal genetically predicted liability for CHD with lifelong risk of APOs. We hypothesized that associations would be found for women, but not their male partners (negative controls).

METHODS

We studied up to 83,969‬ women (and up to 55,568‬ male partners) from the Norwegian Mother, Father and Child Cohort Study or the Trøndelag Health Study with genotyping data and lifetime history of any APO in their pregnancies (1967-2019) in the Medical Birth Registry of Norway (miscarriage, stillbirth, hypertensive disorders of pregnancy, gestational diabetes, small for gestational age, large for gestational age, and spontaneous preterm birth). Maternal and paternal genetic risk scores (GRS) for CHD were generated using 148 gene variants (p-value < 5 × 10-8, not in linkage disequilibrium). Associations between GRS for CHD and each APO were determined using logistic regression, adjusting for genomic principal components, in each cohort separately, and combined using fixed effects meta-analysis.

RESULTS

One standard deviation higher GRS for CHD in women was related to increased risk of any hypertensive disorders of pregnancy (odds ratio [OR] 1.08, 95% confidence interval [CI] 1.05-1.10), pre-eclampsia (OR 1.08, 95% CI 1.05-1.11), and small for gestational age (OR 1.04, 95% CI 1.01-1.06). Imprecise associations with lower odds of large for gestational age (OR 0.98, 95% CI 0.96-1.00) and higher odds of stillbirth (OR 1.04, 95% CI 0.98-1.11) were suggested. These findings remained consistent after adjusting for number of total pregnancies and the male partners' GRS and restricting analyses to stable couples. Associations for other APOs were close to the null. There was weak evidence of an association of paternal genetically predicted liability for CHD with spontaneous preterm birth in female partners (OR 1.02, 95% CI 0.99-1.05), but not with other APOs.

CONCLUSIONS

Hypertensive disorders of pregnancy, small for gestational age, and stillbirth may unmask women with a genetically predicted propensity for CHD. The association of paternal genetically predicted CHD risk with spontaneous preterm birth in female partners needs further exploration.

Deciphering maternal-fetal cross-talk in the human placenta during parturition using single-cell RNA sequencing

Labor is a complex physiological process requiring a well-orchestrated dialogue between the mother and fetus. However, the cellular contributions and communications that facilitate maternal-fetal cross-talk in labor have not been fully elucidated. Here, single-cell RNA sequencing (scRNA-seq) was applied to decipher maternal-fetal signaling in the human placenta during term labor. First, a single-cell atlas of the human placenta was established, demonstrating that maternal and fetal cell types underwent changes in transcriptomic activity during labor. Cell types most affected by labor were fetal stromal and maternal decidual cells in the chorioamniotic membranes (CAMs) and maternal and fetal myeloid cells in the placenta. Cell-cell interaction analyses showed that CAM and placental cell types participated in labor-driven maternal and fetal signaling, including the collagen, C-X-C motif ligand (CXCL), tumor necrosis factor (TNF), galectin, and interleukin-6 (IL-6) pathways. Integration of scRNA-seq data with publicly available bulk transcriptomic data showed that placenta-derived scRNA-seq signatures could be monitored in the maternal circulation throughout gestation and in labor. Moreover, comparative analysis revealed that placenta-derived signatures in term labor were mirrored by those in spontaneous preterm labor and birth. Furthermore, we demonstrated that early in gestation, labor-specific, placenta-derived signatures could be detected in the circulation of women destined to undergo spontaneous preterm birth, with either intact or prelabor ruptured membranes. Collectively, our findings provide insight into the maternal-fetal cross-talk of human parturition and suggest that placenta-derived single-cell signatures can aid in the development of noninvasive biomarkers for the prediction of preterm birth.

Roles of immune microenvironment in the female reproductive maintenance and regulation: novel insights into the crosstalk of immune cells

Female fertility decline is an accumulative consequence caused by complex factors, among them, the disruption of the immune profile in female reproduction stands out as a crucial contributor. Presently, the effects of immune microenvironment (IME) on the female reproductive process have attracted increasing attentions for their dynamic but precisive roles. Immunocytes including macrophages, dendritic cells, T cells, B cells and neutrophils, with diverse subpopulations as well as high plasticity functioned dynamically in the process of female reproduction through indirect intercellular communication via specific cytokine release transduced by molecular signal networks or direct cell-cell contact to maintain the stability of the reproductive process have been unveiled. The immune profile of female reproduction in each stage has also been meticulously unveiled. Especially, the application of single-cell sequencing (scRNA-seq) technology in this process reveals the distribution map of immune cells, which gives a novel insight for the homeostasis of IME and provides a research direction for better exploring the role of immune cells in female reproduction. Here, we provide an all-encompassing overview of the latest advancements in immune modulation within the context of the female reproductive process. Our approach involves structuring our summary in accordance with the physiological sequence encompassing gonadogenesis, folliculogenesis within the ovaries, ovulation through the fallopian tubes, and the subsequent stages of embryo implantation and development within the uterus. Our overarching objective is to construct a comprehensive portrayal of the immune microenvironment (IME), thereby accentuating the pivotal role played by immune cells in governing the intricate female reproductive journey. Additionally, we emphasize the pressing need for heightened attention directed towards strategies that focus on immune interventions within the female reproductive process, with the ultimate aim of enhancing female fertility.

High amniotic fluid fractalkine and MIP-1β levels are associated with intrauterine growth restriction: a prospective cohort study

Background/aim

Proinflammatory chemokines have been shown to play crucial roles in implantation, spiral artery invasion, and the fetomaternal immunological response. In this context, we investigated the levels of fractalkine (CX3CL1) and chemokine CC motif ligand 4 (CCL4 or MIP-1β) in maternal serum and amniotic fluids in pregnant women with intrauterine growth restriction (IUGR).

Materials and methods

This prospective cohort study was carried out at Fırat University Obstetrics Clinic between January 1, 2022 and July 1, 2022. Group (G) 1: The control group consisted of 40 pregnant women who underwent elective cesarean section (CS) at 38-40 weeks of gestation. G2: A total of 40 pregnant women with IUGR at 28-37 weeks of gestation were included in the study group. Levels of tumor necrosis factor-alpha (TNF-α), interleukin-1 beta (IL-1β), interferon-gamma (IFN-γ), hypoxia-inducible factor-1 alpha (HIF-1α), macrophage inflammatory protein-1 beta (MIP-1β), and fractalkine were measured in maternal serum and amniotic fluid samples obtained during CS.

Results

When maternal age was compared, no statistically significant difference was observed between G1 and G2 (p = 0.374). The number of gravidity was found to be statistically higher in G1 compared to G2 (p = 0.003). The mean gestational week was statistically higher in G1 (p < 0.001). Maternal serum MIP-1β (p = 0.03) and IFN-γ (p = 0.006) levels were higher in G1. The birth weight of the baby (p < 0.001) and umbilical cord blood gas pH value (p < 0.001) at birth were higher in G1. HIF-1α (p < 0.001), fractalkine (p < 0.001), MIP-1β (p < 0.001), TNF-α (p = 0.007), IL-1β (p < 0.001), and IFN-γ levels (p = 0.007) in amniotic fluid were higher in G2.

Conclusion

Elevated levels of proinflammatory factors, including fractalkine and MIP-1β, along with inflammatory factors such as TNF-α, IL-1β, and IFN-γ, as well as increased HIF-1α levels in amniotic fluid, are associated with intrauterine growth restriction (IUGR) attributed to a hypoxic amniotic environment.

The Placenta and Neonatal Encephalopathy with a Focus on Hypoxic-Ischemic Encephalopathy

Background: Placental examination is important for its diagnostic immediacy to correlate with maternal and/or fetal complications and parturitional difficulties. In a broader context, clinicopathologic studies of the placenta have addressed a range of pathogenetic questions that have led to conclusive and inconclusive results and interpretations. Methods: Recent standardized morphologic criteria and terminology of placental lesions have facilitated the ability to compare findings from studies that have focused on complications and outcomes of pregnancy. This review is an evaluation of recent studies on placental lesions associated with hypoxic-ischemic encephalopathy (HIE). Conclusion: No apparent consensus exists on whether it is fetal inflammation with the release of cytokines or chronic maternal and/or fetal vascular malperfusion is responsible for HIE with a lowering of the threshold for hypoxic ischemia. The counter argument is that HIE occurs solely as an intrapartum event. Additional investigation is necessary.

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.

Association between pre-pregnancy body mass index and the risk of preterm birth: a mediating effect of hypertensive disorders of pregnancy

OBJECTIVE

We aim to explore the mediating effect of hypertensive disorders of pregnancy (HDP) on the relationship between pre-pregnancy body mass index (BMI) and the risk of preterm birth (PTB) in women with singleton live births.

METHODS

Demographic and clinical data of 3,249,159 women with singleton live births were extracted from the National Vital Statistics System (NVSS) database in this retrospective cohort study. The associations between pre-pregnancy BMI and HDP, HDP, and PTB, and pre-pregnancy BMI and PTB were evaluated using univariate and multivariate logistic regression analyses, with odds ratios (ORs) and 95% confidence intervals (CIs). Structural equation modeling (SEM) was used to explore the mediating effect of HDP on the relationship between pre-pregnancy BMI and PTB.

RESULTS

In total, 324,627 women (9.99%) had PTB. After adjustment for covariables, there were significant associations between pre-pregnancy BMI and HDP [OR = 2.07, 95% CI: 2.05-2.09)], HDP and PTB [OR = 2.54, 95% CI: (2.52-2.57)], and pre-pregnancy BMI and PTB [OR = 1.03, 95% CI: 1.02-1.03)]. The effect of pre-pregnancy BMI on PTB was significantly mediated by HDP with a mediation proportion of 63.62%, especially in women of different ages and having gestational diabetes mellitus (GDM) or not.

CONCLUSION

HDP may play a mediating role in the effect of pre-pregnancy BMI on PTB risk. Women preparing for pregnancy should pay close attention to BMI, and pregnant women should monitor and develop interventions for HDP to reduce the risk of PTB.

Cross-sectional associations between prenatal maternal per- and poly-fluoroalkyl substances and bioactive lipids in three Environmental influences on Child Health Outcomes (ECHO) cohorts

Background

Per- and poly-fluoroalkyl substances (PFAS) exposure can occur through ingestion of contaminated food and water, and inhalation of indoor air contaminated with these chemicals from consumer and industrial products. Prenatal PFAS exposures may confer risk for pregnancy-related outcomes such as hypertensive and metabolic disorders, preterm birth, and impaired fetal development through intermediate metabolic and inflammation pathways.

Objective

Estimate associations between maternal pregnancy PFAS exposure (individually and as a mixture) and bioactive lipids.

Methods

Our study included pregnant women in the Environmental influences on Child Health Outcomes Program: Chemicals in our Bodies cohort (CiOB, n=73), Illinois Kids Developmental Study (IKIDS, n=287), and the ECHO-PROTECT cohort (n=54). We measured twelve PFAS in serum and 50 plasma bioactive lipids (parent fatty acids and eicosanoids derived from cytochrome p450, lipoxygenase, and cyclooxygenase) during pregnancy (median 17 gestational weeks). Pairwise associations across cohorts were estimated using linear mixed models and meta-analysis. Associations between the PFAS mixture and individual bioactive lipids were estimated using quantile g-computation.

Results

PFDeA, PFOA, and PFUdA were associated (p<0.05) with changes in bioactive lipid levels in all three enzymatic pathways (cyclooxygenase [n=6 signatures]; cytochrome p450 [n=5 signatures]; lipoxygenase [n=7 signatures]) in at least one combined cohort analysis. The strongest signature indicated that a doubling in PFOA corresponded with a 24.3% increase (95% CI [7.3%, 43.9%]) in PGD2 (cyclooxygenase pathway) in the combined cohort. In the mixtures analysis, we observed nine positive signals across all pathways associated with the PFAS mixture. The strongest signature indicated that a quartile increase in the PFAS mixture was associated with a 34% increase in PGD2 (95% CI [8%, 66%]), with PFOS contributing most to the increase.

Conclusions

Bioactive lipids were revealed as biomarkers of PFAS exposure and could provide mechanistic insights into PFAS' influence on pregnancy outcomes, informing more precise risk estimation and prevention strategies.

Primary prevention with vaginal chlorhexidine before 16 weeks reduces the incidence of preterm birth: results of the Preterm Labor Prevention Using Vaginal Antiseptics study

BACKGROUND

Preterm labor is one of the leading causes of perinatal death and is currently considered a syndrome with many causes. One of the most important causes of preterm birth is ascending infection from bacterial vaginosis. Chlorhexidine has proven to be effective against bacterial vaginosis and against bacterial biofilms without affecting gestation.

OBJECTIVE

We aimed to evaluate the effectiveness of a universal primary prevention strategy for preterm birth using intravaginal chlorhexidine applied before 16 weeks (Preterm Labor Prevention Using Vaginal Antiseptics study).

STUDY DESIGN

We performed a prospective observational study with 2 cohorts of pregnant women that were assigned either to prevention of preterm birth by means of intravaginal chlorhexidine (Cum Laude Chlorhexidine, chlorhexidine digluconate 0.2%) before 16 weeks (n=413), or to no treatment following the usual hospital protocol (n=704). Primary outcomes were the incidence of spontaneous preterm birth before 34 and 37 weeks; the incidence of preterm birth before 34 and 37 weeks, including inductions for premature rupture of membranes; and the incidence of preterm birth before 34 and 37 weeks, including any indication for termination of pregnancy. Both cohorts were compared using Mann-Whitney and Fisher tests. Finally, a multivariable analysis, including the odds ratio was performed, adjusting for clinical parameters, to evaluate the importance of the different determinants in the prediction of preterm birth.

RESULTS

In pregnancies treated with chlorhexidine, the incidences of spontaneous preterm birth; preterm birth, including induction for premature rupture of membranas; and preterm birth, including any indication for termination of pregnancy were at 34 and 37 weeks: 0% and 0%, 0.24% and 1.69, and 2.90% and 3.15%, respectively; whereas in nontreated pregnancies, these incidences were 9% and 11%, 12% and 23%, and 35% and 43%, respectively. According to the multivariable analysis, the incidence of preterm birth among women treated with chlorhexidine before 16 weeks was halved (Odds ratio, 0.52; P<.05).

CONCLUSION

Universal treatment with vaginal chlorhexidine before 16 weeks reduces the incidence of preterm birth, especially before 34 weeks.

Amniotic fluid sludge is associated with earlier preterm delivery and raised cervicovaginal interleukin 8 concentrations

BACKGROUND

Preterm birth is the leading cause of global neonatal mortality. Amniotic fluid sludge, thought to indicate intra-amniotic infection, may have potential as a clinical biomarker of preterm birth risk.

OBJECTIVE

This study aimed to analyze whether the presence of amniotic fluid sludge in pregnant participants with a known short cervical length can help improve the understanding of the etiology and guide management choice.

STUDY DESIGN

This was a retrospective cohort study analyzing the effects of amniotic fluid sludge presence on the risk of preterm birth in high-risk asymptomatic pregnant participants with a short cervical length (<25 mm) at a large tertiary referral maternity center in London. Amniotic fluid sludge was detected on a routine transvaginal ultrasound scan.

RESULTS

Overall, 147 pregnant participants with a short cervical length were identified, 54 of whom had amniotic fluid sludge. Compared with pregnant participants without amniotic fluid sludge, pregnant participants with amniotic fluid sludge were more likely to have a short cervical length (19 vs 14 mm, respectively; P<.0001) and increased cervicovaginal fetal fibronectin concentrations at diagnosis (125 vs 45 ng/mL, respectively; P=.0006). Pregnant participants with amniotic fluid sludge were at increased risk of midtrimester loss and delivery before 24 weeks of gestation (relative risk, 3.4; 95% confidence interval, 1.2-10.3). Furthermore, this study showed that pregnant participants with amniotic fluid sludge have increased cervicovaginal interleukin 8 concentrations, supporting the concept of amniotic fluid sludge as an indicator of an inflammatory response to microbial invasion (P=.03). Neonatal outcomes were similar between the 2 groups.

CONCLUSION

In our cohort of high-risk asymptomatic pregnant participants with a short cervical length, the presence of amniotic fluid sludge is associated with an increased risk of delivery before 24 weeks of gestation. Moreover, pregnant participants with amniotic fluid sludge were more likely to have raised fetal fibronectin levels and inflammatory cytokines, particularly interleukin 8, in the cervicovaginal fluid, supporting the concept that amniotic fluid sludge is associated with an infective or inflammatory process. Future research should aim to further establish the clinical significance of amniotic fluid sludge presence and guide subsequent management.

Immunosequencing and Profiling of T Cells at the Maternal-Fetal Interface of Women with Preterm Labor and Chronic Chorioamnionitis

T cells are implicated in the pathophysiology of preterm labor and birth, the leading cause of neonatal morbidity and mortality worldwide. Specifically, maternal decidual T cells infiltrate the chorioamniotic membranes in chronic chorioamnionitis (CCA), a placental lesion considered to reflect maternal anti-fetal rejection, leading to preterm labor and birth. However, the phenotype and TCR repertoire of decidual T cells in women with preterm labor and CCA have not been investigated. In this study, we used phenotyping, TCR sequencing, and functional assays to elucidate the molecular characteristics and Ag specificity of T cells infiltrating the chorioamniotic membranes in women with CCA who underwent term or preterm labor. Phenotyping indicated distinct enrichment of human decidual effector memory T cell subsets in cases of preterm labor with CCA without altered regulatory T cell proportions. TCR sequencing revealed that the T cell repertoire of CCA is characterized by increased TCR richness and decreased clonal expansion in women with preterm labor. We identified 15 clones associated with CCA and compared these against established TCR databases, reporting that infiltrating T cells may possess specificity for maternal and fetal Ags, but not common viral Ags. Functional assays demonstrated that choriodecidual T cells can respond to maternal and fetal Ags. Collectively, our findings provide, to our knowledge, novel insight into the complex processes underlying chronic placental inflammation and further support a role for effector T cells in the mechanisms of disease for preterm labor and birth. Moreover, this work further strengthens the contribution of adaptive immunity to the syndromic nature of preterm labor and birth.