Prevalência de nascimentos prematuros como desfechos de infecções pela COVID-19 na gestação / Prevalence of Preterm Birth as an Outcome of COVID-19 Infections during Pregnancy / Prevalencia de nacimientos prematuros producto de la infección por COVID-19 durante el embarazo

Objetivo: estimar a prevalência de nascimento prematuro em gestantes infectadas pela Covid-19, comparar índices de prematuridade entre infectadas e não infectadas e elucidar fatores associados à prematuridade. Métodos: coorte retrospectiva, com coleta de dados por inquérito online, de abril a dezembro de 2022, com mulheres que estiveram gestantes durante a pandemia, com acesso à internet, idade superior a 18 anos e que preencheram o primeiro inquérito online. Protocolo de pesquisa aprovado pelo Comitê de Ética. Resultados: primeiro inquérito respondido por 304 gestantes/puérperas, e o segundo por 82 (27%), compondo a amostra final. O índice de prematuridade no primeiro inquérito foi de 7,2% (n=14), já no segundo, 8,5% (n=7). A infecção pela Covid-19 não foi associada à prematuridade. A prematuridade associou-se a baixo peso, à necessidade de internação em centros de terapia intensiva neonatal e internações após o nascimento. Conclusão: a infecção pela Covid-19 não influenciou no aumento de nascimentos prematuros.

Objective: to estimate the prevalence of preterm birth in pregnant women infected with Covid-19, compare prematurity rates between infected and non-infected, and elucidate factors associated with prematurity. Methods: a retrospective cohort study was conducted using online survey data collected from April to December 2022, involving women who were pregnant during the pandemic, had internet access, were over 18 years old, and completed the initial online survey. The research protocol was approved by the Ethics Committee. Results: the initial survey was completed by 304 pregnant/postpartum women, and the follow-up survey by 82 (27%), comprising the final sample. The preterm birth rate in the initial survey was 7.2% (n=14), and in the follow-up survey, it was 8.5% (n=7). Covid-19 infection was not associated with prematurity. Prematurity was associated with low birth weight, the need for neonatal intensive care unit admission, and postnatal hospitalizations. Conclusion: Covid-19 infection did not influence an increase in preterm births.

Objetivo: estimar la prevalencia de partos prematuros en gestantes infectadas por Covid-19, comparar las tasas de prematuridad entre gestantes infectadas y no infectadas y determinar los factores asociados a la prematuridad. Métodos: estudio de cohorte retrospectivo, con recolección de datos mediante encuesta online, de abril a diciembre de 2022, con mujeres que estuvieron embarazadas durante la pandemia, con acceso a internet, mayores de 18 años y que completaron la primera encuesta online. El protocolo de investigación fue aprobado por el Comité de Ética. Resultados: la primera encuesta fue respondida por 304 gestantes/puérperas, y la segunda por 82 (27%), que conformaron la muestra final. La tasa de prematuridad en la primera encuesta fue del 7,2% (n=14), en la segunda, del 8,5% (n=7). La infección por Covid-19 no se asoció con la prematuridad. La prematuridad se asoció con bajo peso, necesidad de internación en centros de cuidados intensivos neonatales e internaciones después del nacimiento. Conclusión: La infección por Covid-19 no influyó en el aumento de nacimientos prematuros.

When a baby is born, so is a parent: Understanding the effects of preterm birth on Black parents through the lens of the NIMHD framework.

BACKGROUND: The rate of preterm birth (PTB) is high in the United States and Black infants remain disproportionately affected, with the disparity between Black and White infant deaths greater today than it was under antebellum slavery. PURPOSE: The National Institute on Minority Health and Disparities Research Framework reflects a unique set of determinants relevant to the understanding and promotion of minority health. METHODS: We have applied this framework to better understand the effects of PTB on Black parents and the distribution of the social determinants of health, including structural determinants and root causes of inequities. DISCUSSION: This adaptation shows the intersection in maternal and infant health that shapes individuals' experiences, drives disparities and impacts perinatal outcomes in critical periods over the lifecourse. CONCLUSION: In our efforts to achieve health equity, it is imperative that we study the underlying mechanisms and recognize that policies, institutional structures, and social factors are drivers of racism.

Exploring the association between atmospheric pollutants and preterm birth risk in a river valley city.

Objective: To investigate the association between exposure to atmospheric pollutants and preterm birth in a river valley-type city and its critical exposure windows. Methods: A retrospective cohort study was used to collect data from the medical records of preterm and full-term deliveries in two hospitals in urban areas of a typical river valley-type city from January 2018 to December 2019. A total of 7,288 cases were included in the study with general information such as pregnancy times, the number of cesarean sections, occupation, season of conception and regularity of the menstrual cycle. And confounding factors affecting preterm birth were inferred using the chi-square test. The effects of exposure to each pollutant, including particulate matter 2.5 (PM2.5), particulate matter 10 (PM10), nitrogen dioxide (NO2), sulfur dioxide (SO2), carbon monoxide (CO) and ozone (O3), during pregnancy on preterm birth and the main exposure windows were explored by establishing a logistic regression model with pollutants introduced as continuous variables. Results: Maternal age, pregnancy times, number of births, number of cesarean sections, season of conception, complications diseases, comorbidities diseases, hypertension disorder of pregnancy and neonatal low birth weight of the newborn were significantly different between preterm and term pregnant women. Logistic regression analysis after adjusting for the above confounders showed that the risk of preterm birth increases by 0.9, 0.6, 2.4% in T2 and by 1.0, 0.9, 2.5% in T3 for each 10 µg/m3 increase in PM2.5, PM10, NO2 concentrations, respectively. The risk of preterm birth increases by 4.3% in T2 for each 10 µg/m3 increase in SO2 concentrations. The risk of preterm birth increases by 123.5% in T2 and increases by 188.5% in T3 for each 10 mg/m3 increase in CO concentrations. Conclusion: Maternal exposure to PM2.5, PM10, NO2, CO was associated with increased risk on preterm birth in mid-pregnancy (T2) and late pregnancy (T3), SO2 exposure was associated with increased risk on preterm birth in mid-pregnancy (T2).

Association Between Particulate Matter Exposure and Preterm Birth in Women With Abnormal Preconception Thyrotropin Levels: Large Cohort Study.

Background: Prior research has linked exposure to particulate matter with an aerodynamic diameter of ≤2.5 µm (PM2.5) with preterm birth (PTB). However, the modulating effect of preconception thyroid stimulating hormone (TSH) levels on the relationship between PM2.5 exposure and PTB has not been investigated. Objective: This study aimed to assess whether preconception TSH levels modulate the impact of PM2.5 exposure on PTB. Methods: This cohort study was conducted in Guangdong, China, as a part of the National Free Pre-Pregnancy Checkups Project. PM2.5 exposure was estimated by using the inverse distance weighting method. To investigate the moderating effects of TSH levels on trimester-specific PM2.5 exposure and PTB, we used the Cox proportional hazards model. Additionally, to identify the susceptible exposure windows for weekly specific PM2.5 exposure and PTB, we built distributed lag models incorporating Cox proportional hazards models. Results: A total of 633,516 women who delivered between January 1, 2014, to December 31, 2019, were included. In total, 34,081 (5.4%) of them had abnormal preconception TSH levels. During the entire pregnancy, each 10-µg/m3 increase in PM2.5 was linked to elevated risks of PTB (hazard ratio [HR] 1.559, 95% CI 1.390-1.748), early PTB (HR 1.559, 95% CI 1.227-1.980), and late PTB (HR 1.571, 95% CI 1.379-1.791) among women with abnormal TSH levels. For women with normal preconception TSH levels, PM2.5 exposure during the entire pregnancy was positively associated with the risk of PTB (HR 1.345, 95% CI 1.307-1.385), early PTB (HR 1.203, 95% CI 1.126-1.285), and late PTB (HR 1.386, 95% CI 1.342-1432). The critical susceptible exposure windows were the 3rd-13th and 28th-35th gestational weeks for women with abnormal preconception TSH levels, compared to the 1st-13th and 21st-35th gestational weeks for those with normal preconception TSH levels. Conclusions: PM2.5 exposure was linked with a higher PTB risk, particularly in women with abnormal preconception TSH levels. PM2.5 exposure appears to have a greater effect on pregnant women who are in the early or late stages of pregnancy.

Mendelian randomization analysis reveals a causal relationship between preterm birth and myopia risk.

Background: Preterm birth has been associated with an increased risk of myopia, but the causal relationship between these two factors remains unclear. Traditional epidemiological studies are limited by confounding factors and reverse causality. Mendelian randomization (MR) analysis, utilizing genetic variants as instrumental variables, provides a robust approach to investigate causal relationships. In this study, we aimed to explore the potential causal link between preterm birth and myopia risk using a two-sample MR analysis strategy. Methods: We conducted a Mendelian randomization study to investigate the causal relationship between preterm birth and myopia risk. Genetic variants (single nucleotide polymorphisms, SNPs) were used as instrumental variables, and summary data from genome-wide association studies (GWAS) were utilized. Four regression models, including MR-Egger regression, weighted median regression, inverse variance weighted regression, and Weighted mode regression, were employed to validate the causal relationship. Sensitivity analysis was performed using the leave-one-out method. At the same time, the funnel diagram and MR-Egger test were used to judge the stability of the research results. Results: The MR analysis revealed a significant causal effect of preterm birth on myopia risk. Both the inverse variance weighted regression and weighted median regression models showed a p-value less than 0.05, indicating a robust association. The risk of myopia increased by approximately 30% for everyone standard deviation increase in preterm birth. Sensitivity analysis, funnel plot and MR-Egger test all confirm the stability of the research results. Conclusion: Our findings provide evidence supporting a causal relationship between preterm birth and myopia risk. Preterm infants are at a higher risk of developing myopia, and this association is not likely to be influenced by confounding factors or reverse causality. The SNP loci rs6699397, rs10871582, and rs2570497 should be closely monitored as they may lead to abnormal concentrations of intraocular cytokines, particularly vascular endothelial growth factor, potentially elucidating one of the pathogenic mechanisms contributing to the higher incidence of myopia in preterm infants. However the complex interconnections involved extend beyond these factors alone.

Delayed interval delivery and survivability of the second twin with and without emergency cerclage in dichorionic diamniotic pregnancy. A systematic review.

BACKGROUND: There are no systematic reviews analyzing cervical cerclage's role in improving the perinatal outcome of the second twin in dichorionic diamniotic (DCDA) pregnancies following a second trimester or very early preterm birth of the first twin. OBJECTIVE: The primary objective of this systematic review was to evaluate the effect of rescue cervical cerclage on delaying the delivery of the second twin after the delivery of the first twin in DCDA twin pregnancies. The secondary objective was to analyze the effect of rescue cervical cerclage on the perinatal outcome of the second twin in DCDA pregnancies compared to the non-cerclage group. METHODS: A literature search was performed using PubMed, Medline databases, and the Cochrane Library. The studies selected were limited to human subjects and published online by December 2023. Two sets of results in this systematic review are described; the first set includes the outcomes of pregnancies with a DCDA twin pregnancy from the cohort of case series. The meta-analysis was performed for the cohort, and a combined narrative report was provided for the second set of results for the case reports. RESULTS: A literature search resulted in 27 case series and 36 case reports. The case series analysis demonstrated that the mean gestation age of twin 2 at delivery with cervical cerclage (27.5 weeks) compared to those without cervical cerclage (24.4 weeks) was statistically significant (p < 0.001). Furthermore, analysis of the case series showed that twin 2 with cerclage had a statistically significant increase in latency period (days 44.7 vs 23.67) and birth weight (grams 3320 vs 2460) compared to the group without cerclage (p = -value was 0.001 and 0.01, respectively). It is difficult to draw any significant conclusion with complications of cervical cerclage; however, there were slightly more chorioamnionitis and respiratory distress syndrome in the cerclage group. The case report analysis showed no significant difference with or without cervical cerclage. CONCLUSIONS: From this review, it can be concluded that in DCDA twin pregnancies, cervical cerclage insertion after the extremely premature delivery or miscarriage of twin 1 may increase the gestational age at delivery, prolong the delivery interval, and increase the birth weight of twin 2. However, a large prospective multicenter randomized control trial should be performed to assess the benefit of cervical cerclage in DCDA twins to improve the delivery interval latency period and perinatal outcome of twin 2 after the delivery of twin 1.

Endometriosis and risk of adverse pregnancy outcomes: a retrospective multicenter cohort study.

OBJECTIVES: To investigate: first, the association between endometriosis and preterm birth; second, the associations between endometriosis and preeclampsia, placenta previa, postpartum hemorrhage, stillbirth, and small-for-gestational-age infants (assessed by birthweight); and third, the risk of these adverse pregnancy outcomes with and without the use of medically assisted reproduction. DESIGN: Multicenter retrospective cohort study. SETTING: 103 French maternity units. SUBJECTS: Deliveries by 368,935 women (377,338 infants) from 1999 through 2016. EXPOSURE: Endometriosis, defined as a single disease entity (endometriosis and/or ademyosis). MAIN OUTCOMES MEASURES: The main outcome was the preterm birth rate (both < 37 and < 33 weeks). The secondary outcomes were rates of preeclampsia, placenta previa, postpartum hemorrhage, stillbirth, and small-for-gestational-age neonates. RESULTS: Women in the endometriosis group had more frequent histories of infertility before the included pregnancy (34.7 vs 5.0%, P <10-4), more hospitalizations during the pregnancy (27.4 vs. 19.8%, P <10-4), and more planned cesarean sections (14.0 vs. 8.7, P <10-4); they were more often nulliparous (51.7 vs. 43.4%, P <10-4). The prevalence of preterm birth <37 weeks was 11.1% in the endometriosis group and 7.7% in the unexposed group, and <33 weeks 3.1% and 2.2% respectively. The adjusted relative risk for confounding factors was higher in the endometriosis than the unexposed group for preterm delivery <37 weeks (1.40, 95%CI 1.18-1.67) or <33 weeks (1.53, 95%CI 1.08-2.16). For the secondary outcomes, the adjusted risk ratios for preeclampsia, placenta previa, postpartum hemorrhage, and small-for-gestational-age status <10th and < 5th percentiles were higher in the endometriosis group. The adjusted risk ratios for stillbirth and small-for-gestational-age status <3rd percentile did not differ between the two groups, and those after stratification by medically assisted reproduction for preterm birth <37 and <33 weeks did not differ statistically significantly between them for the secondary outcomes, only the risk of placenta previa was higher in the medically assisted reproduction and no-medically assisted reproduction subgroups. CONCLUSION: Pregnant women with endometriosis had higher risks of preterm birth and other poor pregnancy outcomes than women without endometriosis.

Periviability for the Ob-Gyn Hospitalist.

Periviable birth refers to births occurring between 20 0/7 and 25 6/7 weeks gestational age. Management of pregnant people and neonates during this fragile time depends on the clinical status, as well as the patient's wishes. Providers should be prepared to counsel patients at the cusp of viability, being mindful of the uncertainty of outcomes for these neonates. While it is important to incorporate the data on projected morbidity and mortality into one's counseling, shared-decision making is most essential to caring for these patients and optimizing outcomes for all.

Disparities in exposure to concentrated animal feeding operations (CAFOs) and risk of adverse birth outcomes in Pennsylvania, USA.

Background: Previous studies have linked exposure to concentrated animal feeding operations (CAFOs) with various health outcomes. However, relatively few studies evaluated the impacts of CAFOs on adverse birth outcomes, despite significant public health concerns regarding maternal and child health. Objectives: This cross-sectional study investigated the risk of adverse birth outcomes associated with CAFOs exposure and evaluated disparities in exposure to CAFOs and associated health outcomes. Methods: We obtained individual-level birth records from 2003 to 2020 from the Pennsylvania Department of Health. We considered two adverse birth outcomes: (1) preterm birth (PTB); and (2) low birth weight (LBW). Exposure was considered as a binary indicator (presence or absence of CAFO) and as categories based on level of exposure. Logistic regression was applied to estimate the association between CAFOs exposure and adverse birth outcomes. Models were adjusted for infant's sex, maternal demographics (age, race/ethnicity, education), prenatal BMI, prenatal care, smoking status, marital status, plurality, WIC status, and urban/rural indicator. We examined both disparities in exposure and in health response. Results: Presence of CAFOs was associated with higher risk of PTB, with an increasing trend with higher levels of CAFOs exposure. Compared to the no CAFO exposure group, the odds ratios for PTB were 1.022 (95 % confidence interval 1.003, 1.043), 1.066 (1.034, 1.100), 1.069 (1.042, 1.097) for low, medium, and high CAFOs exposure groups, respectively. Some maternal characteristics were associated with a higher CAFO-related risk of PTB. Similar associations were observed for LBW for some characteristics such as mother's race/ethnicity, education, WIC status, and urbanicity, although some findings were not statistically significant. Conclusions: Our findings suggest that presence of CAFOs increases risk of preterm birth. Our results indicate that some maternal characteristics may be associated with higher risk of CAFO-related PTB or LBW. This study can inform future research on disparities in CAFO exposure and associated health burden.

Interventions to Mitigate Pregnancy-Related Mortality and Morbidity in Black Birthing People: A Systematic Review.

OBJECTIVE: To conduct a systematic review of interventions to improve perinatal outcomes to mitigate pregnancy-related mortality and morbidity in Black birthing people. DATA SOURCES: We searched five databases from 2000 through the final search date of April 5, 2023: Cumulative Index of Nursing and Allied Health Literature Plus with Full Text (EBSCOhost), Embase (Elsevier), PubMed, and Scopus (Elsevier) and ClinicalTrials.gov. STUDY ELIGIBILITY CRITERIA: Only quantitative studies were eligible including observational and randomized controlled trials. All participants in selected studies must identify as Black or study results must be stratified by race that includes Black birthing people. The study must 1) measure a perinatal outcome of interest 2) occur in the United States and 3) be written in the English language. Studies were excluded if they were published prior to 2000, not published in the English language, or did not meet the criteria above. STUDY APPRAISAL AND SYNTHESIS METHODS: A data extraction template identified intervention type and perinatal outcome. Perinatal outcomes included but were not limited to: cardiovascular disorders, mortality, or preterm delivery. Interventions included: community programs, educational enhancement, individual counseling, medical intervention, or policy. Risk of bias was assessed using the Mixed Method Appraisal Tool. Three investigators assessed studies individually and group consensus was used for a final decision. RESULTS: From 4,302 unique studies, 41 studies met inclusion criteria. Community programs such as the Supplemental Program for Women, Infants, and Children (WIC) and Healthy Start (n=17, 41.5%) were the most common interventions studied. Individual counseling closely followed (n=15, 36.6%). Medical interventions were not among the more commonly used intervention types (n=9, 21.9%). Most articles focused on preterm delivery (n=28, 68.3%). Few articles studied cardiovascular disorders (n=4, 9.8%) or hemorrhage (n=3, 7.3%). No articles studied pregnancy-related morbidity. CONCLUSIONS: Despite current conversations on Black maternal mortality, there is currently limited literature examining interventions addressing perinatal morbidity and mortality in Black birthing people in the United States. These interventions do not address how to mitigate perinatal outcomes of interest. Patient-centered outcomes research is warranted to better understand as well as to resolve inequities related to Black maternal health. VIDEO ABSTRACT.

A Comparison of Sequelae After a Practice Change From Vancomycin to Ampicillin Containing Antibiotic Regimens for Necrotizing Enterocolitis.

The aim of this study was to compare sequelae and acute kidney injury (AKI) occurrence among patients with necrotizing enterocolitis (NEC) after changing institutional guidelines replacing vancomycin with ampicillin for gram-positive coverage. This was a retrospective, single-center cohort analysis of patients from 2016-2020 (n = 73) with NEC at a surgical neonatal intensive care unit with a high community prevalence of methicillin-resistant Staphylococcus aureus (MRSA). Multivariate logistic regression was utilized to assess associations. Twenty-five (34%) patients had at least 1 sequela related to NEC. Ampicillin containing regimens were not associated with any sequelae type or AKI. Postmenstrual age < 29 weeks at diagnosis ([OR] 5.8 [1.2-28.8], P = .03; and receipt of vasopressors [OR] 3.3 [1.1-10.2], P = .04) were independently associated with sequalae. Stage III NEC was independently associated with AKI, OR 10.6 (2-55.6), P = .005. In conclusion, ampicillin-containing regimens are effective for NEC management at our institution despite a high prevalence of MRSA.

Lupus nephritis kidney biopsy characteristics and preterm birth.

Individuals with lupus nephritis (LN) are at high risk of adverse maternal and fetal outcomes in pregnancy. Outside of pregnancy, proliferative lesions on kidney biopsies are associated with disease progression, but these have not been consistently associated with increased risk in pregnancy. This retrospective, single-center study examines how histologic findings, the timing from kidney biopsy to pregnancy, and the clinical features in the first trimester are associated with preterm birth among individuals with LN. Among 35 deliveries in 31 women, the mean gestational age at delivery was 33.8 weeks. The presence of a urine protein-to-creatinine ratio >0.5 g/g in the first trimester was associated with preterm delivery (81% vs. 36%, p = 0.04). Preterm birth was more common in individuals with glomerular crescents on biopsy (89% in those with >20% crescents vs. 50% in those with <20%, p = 0.06). A pregnancy occurring within 2 years after a kidney biopsy was more likely to result in preterm birth than if the biopsy was performed more than 2 years prior to conception (82% vs. 23%, p = 0.01). The time from diagnostic biopsy may be a surrogate for disease activity, and a 2-year delay from biopsy might allow sufficient time to achieve disease remission. Overall, these data could aid family planning discussions and promote preconception disease optimization for patients and their providers.

Lubricating gel influence on vaginal microbiome sampling.

Gel lubrication is routinely used during gynecological examination to prevent or reduce pain, yet its impact on microbial composition during sampling remains unclear. This study aimed to investigate whether lubricating gel affects the microbial composition of vaginal samples. We included 31 pregnant women presenting during their third trimester to clinics or emergency room and collected 143 unique vaginal samples for 16S amplicon microbial analysis. Vaginal samples were obtained using sterile swabs under various conditions: without gel-immediately frozen (n = 30), with gel-immediately frozen, without gel-at room temperature (RT) for 5 h before freezing, with gel-at RT for 5 h before freezing, and additional sampling after 24 h without gel-immediate freezing. We found that sample collection with gel lubrication influenced specimen quality-half of the gel samples failing to meet processing limitation compared to those without gel. The effect of gel on testing quality dissipated after 24 h. However, when samples met post-sequencing filters, gel lubrication did not alter the microbial composition, individual taxa abundance or alpha and beta diversity. We recommend sampling either before gel exposure or 24 h after. These findings underscore the importance of considering sample collection methodologies in vaginal microbiome studies to ensure high-quality microbial data for accurate analysis.

MicroRNA expression profile in the basal plate of human placenta associates with spontaneous preterm birth.

INTRODUCTION: MicroRNAs regulate post-transcriptional gene expression. Their expression has been linked to many pregnancy complications, including preterm birth. Placental microRNA levels differ between preterm and term pregnancies. Not much is known about the targets that are affected by these differences in microRNA expression. We investigated associations between microRNA expression levels in the basal plate of the placenta and their targets and the onset of preterm birth. METHODS: MiRNAomes of spontaneous preterm (n = 6) and term (n = 6) placentas were characterized using RNA sequencing. MicroRNA target and enrichment analyses were performed to explore potential gene targets and pathways. Selected findings were validated using qPCR (n = 41). MicroRNA mimic transfection and luciferase reporter assays were performed to test if certain microRNAs regulate their predicted target, SLIT2, the expression of which has been shown to associate with preterm birth. RESULTS: We identified 39 differentially expressed microRNAs from the preterm placentas compared to term. Many downregulated microRNAs were from the placenta-specific C14MC microRNA cluster. Target gene and pathway analyses showed that microRNAs that associate with preterm birth target transcription related factors and genes linked with protein binding and invasive pathways. Eight of the identified microRNAs putatively target SLIT2, including miR-766-3p and miR-489-3p. Luciferase reporter assay suggested that these microRNAs regulate SLIT2 expression. DISCUSSION: MicroRNA expression changes are associated with spontaneous preterm birth. A group of microRNAs targeting the same gene or genes belonging to the same pathway can have a significant effect on the critical processes maintaining pregnancy and placental functions.

Maternal peripheral blood telomere length and preterm birth in African American women: a pilot study.

PURPOSE: This study aimed to explore the association between preterm birth and telomere length of maternal peripheral blood in African American women. METHODS: 78 African American women were recruited for this study between 2018 and 2023 from 2 prenatal clinics in central and east Texas. Participants provided blood samples and completed clinic questionnaires, with clinical data collected from their post-delivery medical records. Telomere length was measured using monochrome multiplex quantitative real-time polymerase chain reaction. Linear regression and multinomial logistic regression were used to analyze the association between telomere length and gestational length. Kruskal-Wallis's test and Fisher's exact test were used to compare preterm birth, early-term birth and full-term birth by telomere length, social-demographic characteristics, stress and discrimination. RESULTS: The rates of preterm birth was higher in pregnant women with shorter telomeres. After adjusting for confounders, for every 10-units increase in the relative telomere-to-single-copy gene (T/S) ratio, gestational days increased by 1.090 days (90% CI 0.182, 1.997), and for every 10-units decrease in the T/S ratio, the odds of preterm birth was 2.664 (90% CI 1.064, 6.673) times greater than the odds of full-term birth. No statistically significant associations were observed between stress, discrimination, and either preterm birth or telomere length. CONCLUSIONS: Maternal peripheral blood telomere shortening is associated with preterm birth, providing support to further explore the clinical utility of maternal telomere testing for prediction and early intervention of preterm birth and the study of biological mechanisms of spontaneous preterm birth.

Amniotic fluid proteomic analysis identifies IL1RL1, APOE, and NECTIN4 as new biomarkers for preterm birth.

BACKGROUND: Despite extensive research, the identification of effective biomarkers for early prediction of preterm birth (PTB) continues to be a challenging endeavor. This study aims to identify amniotic fluid (AF) protein biomarkers useful for the early diagnosis of PTB. METHODS: We initially identified the protein expression profiles in the AF of women with PTB (n = 22) and full-term birth (FTB, n = 22), from the First People's Hospital of Yunnan Province who underwent amniocentesis from November 2019 to February 2020, using mass spectrometry employing the data-independent acquisition (DIA) technique, and then analyzed differentially expressed proteins (DEPs). Subsequently, the least absolute shrinkage and selection operator (LASSO) and random forest analysis were employed to further screen the key proteins for PTB biomarker identification. The receiver operating characteristic (ROC) analysis, calibration plots, and decision curve analyses (DCA) were utilized to assess the discrimination and calibration of the key biomarkers. RESULTS: A total of 25 DEPs were identified between the PTB and FTB groups, comprising 13 up-regulated and 12 down-regulated proteins. Three key protein biomarkers for early PTB diagnosis were identified: IL1RL1 (interleukin-1 receptor-like 1), APOE (apolipoprotein E), and NECTIN4 (nectin cell adhesion molecule 4). The results of the ROC analysis showed that the area under the curve (AUC) of the three proteins combined as a biomarker for early diagnosis of PTB was 0.913 (95% CI: 0.823-1.000), with a sensitivity of 0.864 and a specificity of 0.955, both superior to those of the individual biomarkers. Bootstrap internal validation revealed a concordance index (C-index) of 0.878, with a sensitivity of 0.812 and a specificity of 0.773, indicating the robust predictive performance of these biomarkers. CONCLUSIONS: We identified three previously unexplored yet potentially useful protein biomarkers in AF for early PTB diagnosis: IL1RL1, APOE, and NECTIN4.

Associations of air pollutants and related metabolites with preterm birth during pregnancy.

OBJECTIVE: This study aimed to investigate the influence of exposure to ambient fine particulate matter (PM2.5) and its components during pregnancy on the prevalence of preterm birth (PTB). Additionally, we sought to identify the susceptible exposure window. Furthermore, we explored the potential mediating role of blood analysis and a comprehensive metabolic panel in the association between pollutant exposure and PTB incidence. METHODS: This birth cohort study recruited 139 participants with PTB outcomes and 1713 controls from Fujian Maternal and Child Health Hospital between January 2021 and June 2023. Sociodemographic characteristics and clinical treatment data during participants' first pregnancies were collected. The exposure levels to pollutants during pregnancy were estimated via a combined geographic-statistical model utilising satellite remote sensing data. The distributional lag nonlinear modelling was employed to assess associations between pollutant exposure during pregnancy and the prevalence of PTB. Weighted quantile regression was used to identify key components associated with PM2.5 and PTB during pregnancy. Additionally, a mediating effect analysis was conducted to evaluate the role of blood analysis. The metabolic profile was used to screen for differentially abundant metabolites associated with PTB and explore their relative expression in relation to air pollutants and PTB incidence. RESULTS: Following the adjustment for potential confounding variables, the mean weekly susceptibility windows for PM2.5 were identified as 7-10, 16-19, and 22-28 weeks; 8-10, and 15-19 weeks for inorganic sulfate; 6-10, and 15-28 weeks for nitrate; 6-12, and 15-28 weeks for ammonium (NH4+); and 7-9, 18-20, and 22-36 weeks for organic matter. During mixed exposure to PM2.5 components, the key component is NH4+. In the mixed exposure to PM2.5 components, NH4+ emerged as a key contributor. The results of the mediation analysis revealed that haemoglobin played a mediating role, accounting for 21.53 % of the association between exposure to environmental pollutants and the prevalence of PTB. It is noteworthy that, no mediating effects were observed for the other variables. Furthermore, non-targeted metabolomics identified 17 metabolites associated with PTB. Among these factors, hydrogen phosphate may impact metabolic pathways such as oxidative phosphorylation, influencing the risk of PTB. The interplay between environmental pollutants and metabolites, particularly through oxidative phosphorylation pathways, may contribute to PTB incidence. CONCLUSIONS: The evidence indicates that exposure to PM2.5 and its components during pregnancy were a significant risk factor for PTB. Notably, specific weekly exposure windows were identified for pollutants during pregnancy. Among the PM2.5 components, NH4+ exhibited the most substantial weight in the association analysis between exposure to the mixture of components and PTB. Furthermore, our mediation analysis revealed that haemoglobin serves as a partial mediator in the relationship between exposure to pollutants during pregnancy and the prevalence of PTB. Additionally, maternal serum metabolic profiles differed between the preterm and control groups. Notably, a combined effect involving hydrogen phosphate and mixed exposure to PM2.5 fractions further contributed to the development of PTB. Oxidative phosphorylation pathways may play pivotal roles in this intricate association.