Spontaneous Preterm Birth Research Articles

Pregnancy outcome following various doses of antioxidants such as Vitamin E supplementation – current state of knowledge

Introduction and purpose: Vitamin E is an antioxidant substance. It has been noted that the pathomechanism of many diseases in pregnancy is rooted in oxidative stress. Much of them have an incompletely understood mechanism, and thus treatment is not as effective. Vitamin E is a readily available and important antioxidant. It is reasonable to investigate whether there are links between supplementation with this vitamin and improved outcomes of conditions in pregnant women. Conditions such as preeclampsia (also in a group of women with type 1 diabetes), preterm premature rupture of membranes, spontaneous preterm birth, respiratory diseases were considered. Material and method: The literature was reviewed in the Pubmed database, GoogleScholar, in the Via Medica journal database, the positions of the Polish gynecological society with the use of keywords. State of knowledge: According to the cited studies, routine use of vitamin E in combination with other supplements has no discernible benefit. No differences were found in groups taking antioxidants from placebo groups in the context of pregnancy diseases. There were side effects of supplementation and for this reason supplementation with this antioxidant should not be ordered without clear indications. Conclusions: The information gathered does not indicate the usefulness of vitamin E supplementation in pregnancy. The issue of the use of antioxidants in the fight against diseases that occur during pregnancy requires further research.

First-Trimester Prediction Models Based on Maternal Characteristics for Adverse Pregnancy Outcomes: A Systematic Review and Meta-Analysis.

Early risk stratification can facilitate timely interventions for adverse pregnancy outcomes, including preeclampsia (PE), small-for-gestational-age neonates (SGA), spontaneous preterm birth (sPTB) and gestational diabetes mellitus (GDM). To perform a systematic review and meta-analysis of first-trimester prediction models for adverse pregnancy outcomes. The PubMed database was searched until 6 June 2024. First-trimester prediction models based on maternal characteristics were included. Articles reporting on prediction models that comprised biochemical or ultrasound markers were excluded. Two authors identified articles, extracted data and assessed risk of bias and applicability using PROBAST. A total of 77 articles were included, comprising 30 developed models for PE, 15 for SGA, 11 for sPTB and 35 for GDM. Discriminatory performance in terms of median area under the curve (AUC) of these models was 0.75 [IQR 0.69-0.78] for PE models, 0.62 [0.60-0.71] for SGA models of nulliparous women, 0.74 [0.72-0.74] for SGA models of multiparous women, 0.65 [0.61-0.67] for sPTB models of nulliparous women, 0.71 [0.68-0.74] for sPTB models of multiparous women and 0.71 [0.67-0.76] for GDM models. Internal validation was performed in 40/91 (43.9%) of the models. Model calibration was reported in 21/91 (23.1%) models. External validation was performed a total of 96 times in 45/91 (49.5%) of the models. High risk of bias was observed in 94.5% of the developed models and in 58.3% of the external validations. Multiple first-trimester prediction models are available, but almost all suffer from high risk of bias, and internal and external validations were often not performed. Hence, methodological quality improvement and assessment of the clinical utility are needed.

Clinical and dental predictors of preterm birth using machine learning methods: the MOHEPI study.

Preterm birth (PTB) is one of the most common and serious complications of pregnancy, leading to mortality and severe morbidities that can impact lifelong health. PTB could be associated with various maternal medical condition and dental status including periodontitis. The purpose of this study was to identify major predictors of PTB among clinical and dental variables using machine learning methods. Prospective cohort data were obtained from 60 women who delivered singleton births via cesarean section (30 PTB, 30 full-term birth [FTB]). Dependent variables were PTB and spontaneous PTB (SPTB). 15 independent variables (10 clinical and 5 dental factors) were selected for inclusion in the machine learning analysis. Random forest (RF) variable importance was used to identify the major predictors of PTB and SPTB. Shapley additive explanation (SHAP) values were calculated to analyze the directions of the associations between the predictors and PTB/SPTB. Major predictors of PTB identified by RF variable importance included pre-pregnancy body mass index (BMI), modified gingival index (MGI), preeclampsia, decayed missing filled teeth (DMFT) index, and maternal age as in top five rankings. SHAP values revealed positive correlations between PTB/SPTB and its major predictors such as premature rupture of the membranes, pre-pregnancy BMI, maternal age, and MGI. The positive correlations between these predictors and PTB emphasize the need for integrated medical and dental care during pregnancy. Future research should focus on validating these predictors in larger populations and exploring interventions to mitigate these risk factors.

Associations of maternal sedentary behavior and physical activity levels in early to mid-pregnancy with infant outcomes: A cohort study.

Physical activity during pregnancy is beneficial for the woman and the fetus. However, non-objective methods are often used to measure physical activity levels during pregnancy. This study aimed to evaluate objectively measured maternal early to mid-pregnancy sedentary behavior and physical activity in relation to infant well-being. This cohort study included 1153 pregnant women and was performed at Uppsala University Hospital, Uppsala, Sweden, between 2016 and 2023. Sedentary behavior and physical activity levels were measured by accelerometers during 4-7 days in early to mid-pregnancy. Outcome measures were infant birthweight standard deviation score, small-for-gestational-age, large-for-gestational-age, preterm birth (<37 weeks' gestation), spontaneous preterm birth, iatrogenic preterm birth, Apgar <7 at 5 min of age, umbilical artery pH ≤7.05, and admission to the neonatal intensive care unit (NICU). There were no associations of sedentary behavior and physical activity levels with infant birthweight standard deviation score, small-for-gestational-age, or large-for-gestational-age. After adjustment for BMI, age, smoking, parity, maternal country of birth, and a composite of pre-pregnancy disease, the most sedentary women had higher odds of preterm birth (adjusted odds ratio (AOR) 2.47, 95% confidence interval (CI) 1.17-5.24, p = 0.018), and NICU admission (AOR 1.93, CI 1.11-3.37, p = 0.021) than the least sedentary women. The most physically active women had lower adjusted odds for NICU admission (AOR 0.45, CI 0.26-0.80, p = 0.006) than the least physically active women. Objectively measured levels of sedentary behavior and physical activity in early to mid-pregnancy were not associated with standardized infant birth size. Sedentary behavior was associated with an increased likelihood of preterm birth and NICU admission, while high level of physical activity was associated with a decreased likelihood of admission to NICU.

Developing a logistic regression model to predict spontaneous preterm birth from maternal socio-demographic and obstetric history at initial pregnancy registration

BackgroundCurrent predictive machine learning techniques for spontaneous preterm birth heavily rely on a history of previous preterm birth and/or costly techniques such as fetal fibronectin and ultrasound measurement of cervical length to the disadvantage of those considered at low risk and/or those who have no access to more expensive screening tools.Aims and objectivesWe aimed to develop a predictive model for spontaneous preterm delivery < 37 weeks using socio-demographic and clinical data readily available at booking -an approach which could be suitable for all women regardless of their previous obstetric history.MethodsWe developed a logistic regression model using seven feature variables derived from maternal socio-demographic and obstetric history from a preterm birth (n = 917) and a matched full-term (n = 100) cohort in 2018 and 2020 at a tertiary obstetric unit in the UK. A three-fold cross-validation technique was applied with subsets for data training and testing in Python® (version 3.8) using the most predictive factors. The model performance was then compared to the previously published predictive algorithms.ResultsThe retrospective model showed good predictive accuracy with an AUC of 0.76 (95% CI: 0.71–0.83) for spontaneous preterm birth, with a sensitivity and specificity of 0.71 (95% CI: 0.66–0.76) and 0.78 (95% CI: 0.63–0.88) respectively based on seven variables: maternal age, BMI, ethnicity, smoking, gestational type, substance misuse and parity/obstetric history.ConclusionPending further validation, our observations suggest that key maternal demographic features, incorporated into a traditional mathematical model, have promising predictive utility for spontaneous preterm birth in pregnant women in our region without the need for cervical length and/or fetal fibronectin.

Protective Effect of EBF Transcription Factor 1 (EBF1) Polymorphism in Sporadic and Familial Spontaneous Preterm Birth: Insights from a Case-Control Study.

This study investigated the potential role of specific single-nucleotide polymorphisms (SNPs) in the genes Astrotactin 1 (ASTN1), EBF Transcription Factor 1 (EBF1), Eukaryotic Elongation Factor, Selenocysteine-tRNA Specific (EEFSEC), Microtubule-Associated Serine/Threonine Kinase 1 (MAST1), and Tumor Necrosis Factor Alpha (TNF-α) to assess whether these genetic variants contribute to the risk of spontaneous preterm birth (sPTB). A case-control study was conducted involving 573 women from Croatia and Slovenia: 248 with sporadic sPTB (positive personal and negative family history of sPTB before 37 weeks' gestation), 44 with familial sPTB (positive personal and family history of sPTB before 37 weeks' gestation), and 281 control women. The analysis of ASTN1 rs146756455, EBF1 rs2963463, EBF1 rs2946169, EEFSEC rs201450565, MAST1 rs188343966, and TNF-α rs1800629 SNPs was performed using TaqMan real-time PCR. p-values were Bonferroni-adjusted for multiple comparisons. EBF1 SNP rs2963463 was significantly associated with sPTB (p adj = 0.03). Women carrying the CC genotype had a 3-4-times lower risk of sPTB (p adj < 0.0001). In addition, a significant difference in the frequency of the minor C allele was observed when comparing familial sPTB cases with controls (p adj < 0.0001). All other associations were based on unadjusted p-values. The minor T allele of EBF1 SNP rs2946169 was more frequent in sPTB cases overall than in controls, especially in sporadic sPTB (p = 0.045). Similarly, the CC genotype of ASTN1 SNP rs146756455 was more frequent in sporadic sPTB cases compared to controls (p = 0.019). Finally, the TNF-α SNP rs1800629 minor A allele and AA genotype were more common in the familial sPTB group compared to sporadic sPTB and controls (p < 0.05). The EBF1 SNP rs2963463 polymorphism showed a protective effect in the pathogenesis of sPTB, particularly in women carrying the CC genotype. Moreover, EBF1 SNP rs2946169 and ASTN1 SNP rs146756455, as well as TNF-α SNP rs1800629, were associated with an increased risk of sPTB, representing suggestive potential risk factors for sporadic and familial sPTB, respectively.

The role of the lower uterine segment thickness in predicting preterm birth in twin pregnancies presenting with threatened preterm labor.

To examine the relationship between the lower uterine segment (LUS) thickness and the onset of labor in dichorionic twin pregnancies experiencing threatened preterm labor. This prospective cohort study included dichorionic twin pregnancies between 24 and 32weeks of gestation, presenting with symptoms of preterm labor. The LUS thickness and mid-anterior wall thickness were measured via transabdominal ultrasonography, cervical length, and posterior cervical lip thickness were measured transvaginally. The presence of the cervical sliding sign and funneling findings were recorded. Among the patients with an onset of labor before the 34th week, the mean LUS thickness was 3.8±0.9 mm, compared to 4.6±1.1 mm in those with an onset of labor at or after 340/7 GW, indicating a statistically significant difference (p=0.012). Similarly, accepting the GW threshold as 350/7 weeks, a statistically significant difference was found in the mean LUS thickness, which was 4.0±1.0 mm in those with an earlier onset of labor and 4.7±1.0 mm in those with a later onset of labor (p=0.022). While univariate analysis indicated that the LUS thickness was a significant predictor (p=0.017 for <34 GW and p=0.028 for <35 GW), multivariate analysis showed a reduced effect (p=0.04 and p=0.06, respectively). LUS was significantly thinner in pregnancies with an onset of labor before the 34th and 35th GW. The measurement of the LUS thickness can be considered an alternative method for predicting spontaneous preterm birth in dichorionic twin pregnancies.

Trends in gestational age at live birth in Scotland from 2005 to 2019: a population-based study

Background Gestation at birth is associated with short and long-term outcomes. This study used high quality, national, administrative data to examine trends in gestation at birth in Scotland. Methods This observational study used maternity hospital discharge records for 2005 to 2019 to determine trends in the percentage of live births that were preterm (&lt;37 weeks gestation), term (37–41 weeks), and post-term (≥42 weeks), overall and by maternal age and deprivation category. Preterm births were further examined by category of preterm birth (moderate to late [32–36 weeks]; very [28–31 weeks]; extremely [&lt;28 weeks] preterm), and onset of labour (spontaneous; provider-initiated). Singleton and multiple births were examined separately. Aggregate logistic regression was used to estimate the annual change in the odds of a birth being in a specified gestational category. Results The percentage of singleton births in Scotland that were preterm decreased from 2005 (6.5%, 3,361/51,665) to 2010 (5.8%, 3268/56344), then increased to 2019 (7.2%, 3,408/47,507). The percentage of singleton births that were spontaneous moderate to late, very, and extremely preterm all increased between 2010 and 2019. The percentage of singleton births that were provider-initiated moderate to late preterm also increased between 2010 and 2019, however provider-initiated very or extremely preterm birth decreased. The percentage of singleton births that were preterm increased over time across all maternal age and deprivation categories, with increases greatest in groups at highest baseline risk. The percentage of singleton births that were post-term increased from 2005 to 2009, then decreased to 2019. Conclusions There has been an increase in spontaneous preterm birth from 2010 to 2019, which is not fully explained by changes in maternal age or deprivation. Further research to examine the contribution of other, preventable, risk factors is warranted. Trends in provider-initiated preterm birth, and post-term birth, are likely to reflect changing clinical practice.

Adverse perinatal outcomes associated with different classes of antiretroviral drugs in pregnant women living with HIV: a systematic review and meta-analysis.

Women living with HIV (WLHIV) are at increased risk of adverse perinatal outcomes compared to HIV-negative women, despite antiretroviral therapy (ART). There is evidence that the risk of adverse perinatal outcomes may differ according to ART regimen. We aimed to assess the risk of adverse perinatal outcomes among WLHIV receiving different classes of ART, compared to HIV-negative women. Systematic review and meta-analysis. We searched Medline, CINAHL, Global Health and EMBASE for studies published between 1 January 1980 and 14 July 2023. We included studies which assessed the risk of 11 predefined adverse perinatal outcomes among WLHIV receiving non-nucleoside reverse transcriptase inhibitor (NNRTI)-based ART, protease inhibitor (PI)-based ART or integrase strand transfer inhibitor (INSTI)-based ART, compared to HIV-negative women. The perinatal outcomes assessed were preterm birth (PTB), very PTB (VPTB), spontaneous PTB (sPTB), low birthweight (LBW), very LBW (VLBW), term LBW, preterm LBW, small for gestational age (SGA), very SGA (VSGA), stillbirth and neonatal death (NND). Random effects meta-analyses examined the risk of each adverse outcome in WLHIV receiving either NNRTI-based, PI-based or INSTI-based ART, compared with HIV-negative women. Subgroup and sensitivity analyses were conducted based on country income status, study quality, and timing of ART initiation. The protocol is registered with PROSPERO, CRD42021248987. Of 108,720 identified citations, 22 cohort studies including 191,857 women were eligible for analysis. We found that WLHIV receiving NNRTI-based ART (mainly efavirenz or nevirapine) are at increased risk of PTB (risk ratio (RR) 1.40, 95% confidence interval 1.27-1.56), VPTB (1.94, 1.25-3.01), LBW (1.63, 1.30-2.04), SGA (1.53, 1.17-1.99) and VSGA (1.48, 1.16-1.87), compared with HIV-negative women. WLHIV receiving PI-based ART (mainly lopinavir/ritonavir or unspecified) are at increased risk of PTB (1.88, 1.55-2.28), VPTB (2.06, 1.01-4.18), sPTB (16.96, 1.01-284.08), LBW (2.90, 2.41-3.50), VLBW (4.35, 2.67-7.09) and VSGA (2.37, 1.84-3.05), compared with HIV-negative women. WLHIV receiving INSTI-based ART (mainly dolutegravir) are at increased risk of PTB (1.17, 1.06-1.30) and SGA (1.20, 1.08-1.33), compared with HIV-negative women. The risks of adverse perinatal outcomes are higher among WLHIV receiving ART compared with HIV-negative women, irrespective of the class of ART drugs. This underlines the need to further optimise ART in pregnancy and improve perinatal outcomes of WLHIV.

Fetal Fraction of Cell-Free DNA in the Prediction of Adverse Pregnancy Outcomes: A Nationwide Retrospective Cohort Study.

To assess the added value of fetal fraction of cell-free DNA in the maternal circulation in the prediction of adverse pregnancy outcomes. Retrospective cohort study. Nationwide implementation study on non-invasive prenatal testing (NIPT; TRIDENT-2 study). Pregnant women in the Netherlands opting for NIPT between June 2018 and June 2019. Two logistic regression prediction models were constructed for each adverse pregnancy outcome. The first model (base model) included prognostic clinical parameters that were selected from existing first-trimester prediction models for adverse pregnancy outcomes. The second model (fetal fraction model) included fetal fraction as a predictor on top of the prognostic clinical parameters included in the base model. The added prognostic value of fetal fraction was assessed by comparing the base and fetal fraction models in terms of goodness of fit and predictive performance. Likelihood ratio test (LRT), area under the curve (AUC) and Integrated Discrimination Improvement (IDI) index. The study cohort consisted of 56 110 pregnancies. The incidence of adverse pregnancy outcomes was 5.7% for hypertensive disorders of pregnancy (HDP; n = 3207), 10.2% for birthweight < p10 (n = 5726), 3.2% for birthweight < p2.3 (n = 1796), 3.4% for spontaneous preterm birth (sPTB; n = 1891), 3.4% for diabetes (n = 1902) and 1.3% for congenital anomalies (n = 741). Adding fetal fraction to the base model improved model fit for HDP, birthweight < p10, birthweight < p2.3, all sPTB, and diabetes, but not for congenital anomalies (LRT p < 0.05). For HDP, the AUC improved from 0.67 to 0.68 by adding fetal fraction to the base model (p = 0.14) with an IDI of 0.0018 (p < 0.0001). For birthweight < p10, the AUC improved from 0.65 to 0.66 (p < 0.0001) with an IDI of 0.0023 (p < 0.0001). For birthweight < p2.3, the AUC improved from 0.67 to 0.69 (p < 0.0001) with an IDI of 0.0011 (p < 0.0001). For all sPTB, the AUC was similar for both models (AUC 0.63, p = 0.021) with an IDI of 0.00028 (p = 0.0023). For diabetes, the AUC was similar (AUC 0.72, p = 0.35) with an IDI of 0.00055 (p = 0.00015). Fetal fraction has statistically significant but limited prognostic value in the prediction of adverse pregnancy outcomes in addition to known prognostic clinical parameters.

Prediction model for spontaneous preterm birth less than 32 weeks of gestation in low-risk women with mid-trimester short cervical length: a retrospective cohort study

BackgroundA short cervix in mid-trimester pregnancy is a risk factor for spontaneous preterm birth. However, there is currently a lack of predictive models and classification systems for predicting spontaneous preterm birth in these patients, especially those without additional risk factors for spontaneous preterm birth.MethodsA retrospective observational cohort study of low-risk singleton pregnant women with a short cervix (≤ 25 mm) measured by transvaginal ultrasonography between 22 and 24 weeks was conducted. A multivariate logistic regression model for spontaneous preterm birth < 32 weeks in low-risk pregnant women with a short cervix was constructed. Moreover, we developed a nomogram to visualize the prediction model and stratified patients into three risk groups (low-, intermediate-, and high-risk groups) based on the total score obtained from the nomogram model.ResultsBetween 2020 and 2022, 213 low-risk women with a short cervix in mid-trimester pregnancy were enrolled in the study. Univariate logistic analysis revealed that a high body mass index, a history of three or more miscarriages, multiparity, a short cervical length, leukocytosis, and an elevated C-reactive protein level were associated with spontaneous preterm birth < 32 weeks, but multivariate analysis revealed that multiparity (OR, 3.31; 95% CI, 1.13–9.68), leukocytosis (OR, 3.96; 95% CI, 1.24–12.61) and a short cervical length (OR, 0.88; 95% CI, 0.82–0.94) were independent predictors of sPTB < 32 weeks. The model incorporating these three predictors displayed good discrimination and calibration, and the area under the ROC curve of this model was as high as 0.815 (95% CI, 0.700-0.931). Patients were stratified into low- (195 patients), intermediate- (14 patients) and high-risk (4 patients) groups according to the model, corresponding to patients with scores ≤ 120, 121–146, and > 146, respectively. The predicted probabilities of spontaneous preterm birth < 32 weeks for these groups were 6.38, 40.62, and 71.88%, respectively.ConclusionsA noninvasive and efficient model to predict the occurrence of spontaneous preterm birth < 32 weeks in low-risk singleton pregnant women with a short cervix and a classification system were constructed in this study and can provide insight into the optimal management strategy for patients with different risk stratifications according to the score chart.

Emerging Roles of IL-27 in Trophoblast Cells and Pregnancy Complications.

Pregnancy complications such as spontaneous abortion, preeclampsia, and preterm birth persist, despite current interventions aimed at their prevention and treatment largely proving unsuccessful. Interleukin-27 (IL-27), composed of p28 and EBI3 subunits, binds to IL-27R, which consists of gp130 and IL-27Rα (also known as WSX-1 or TCCR), and plays a pivotal role in tumor development and inflammation regulation. At the maternal-fetal interface, IL-27 expression has been detected in trophoblasts, endometrial stromal cells, and decidual cells. Abnormal levels of IL-27/IL-27R have been linked to adverse pregnancy outcomes, including spontaneous miscarriage, preeclampsia, and preterm birth. This review aims to explore the expression of IL-27 at the maternal-fetal interface and its signaling pathway, uncovering the complex role of IL-27 in pregnancy complications. A comprehensive literature review was conducted using PubMed/Medline, Scopus, and Embase databases, analyzing studies on IL-27 expression and its signaling pathways at the maternal-fetal interface. The review focused on identifying the presence of IL-27 in various cell types and linking abnormal IL-27/IL-27R expression to pregnancy complications such as spontaneous miscarriage, preeclampsia, and preterm birth. IL-27 plays a complex role at the maternal-fetal interface, with abnormal expression linked to several pregnancy complications. These findings highlight the need for further research to elucidate IL-27's mechanisms and develop targeted interventions. Future studies should aim to develop targeted interventions and improve therapeutic strategies for managing pregnancy complications.

The predictive role of uterocervical angle in labor outcomes: a narrative review.

Uterocervical angle (UCA) is the angle between the anterior or posterior uterine wall and the cervical canal, and it has become an unique ultrasonographic marker in the recent years. The predictive role of the UCA in spontaneous preterm births (sPTB) has been examined by numerous authors, however few data are available on UCA as predictor of labor outcome at term of pregnancy. Therefore, the purpose of this review is to evaluate the effectiveness of transvaginal ultrasound measurement of UCA at term, and its clinical implications in obstetrics' practice. A literature search was conducted including all studies regarding the predictive role of ultrasonographic evaluation of the UCA on labor outcomes from 1990 to 2023. A narrative synthesis was subsequently performed dividing studies that considered posterior and anterior UCA. Five studies were included for the anterior UCA, and ten for the posterior UCA. UCA was then evaluated as predictor of prolonged latent phase and predictor of the onset and mode of delivery. It is likely that the combination of multiple cervical parameters, rather than UCA assessment alone, together with clinical information, can achieve higher levels of accuracy in predicting delivery outcomes. Future prospective studies are needed to define with greater certainty the role of UCA as a useful screening tool before laboring, but, until then, the use of UCA as a screening test to predict labor outcome should remain investigational.

Hepatitis C Virus Infection in Pregnant Individuals with Opioid Use Disorder and Its Association with Preterm Birth.

Both hepatitis C virus (HCV) and opioid use disorder (OUD) have been associated with higher rates of preterm birth (PTB). It is unknown whether the higher prevalence of HCV in individuals with OUD may contribute to this association. The objective of this study is to evaluate the association between HCV and PTB in pregnant individuals with OUD. We conducted a retrospective cohort of pregnant individuals with OUD who participated in more than three visits in a co-located multidisciplinary program. Inclusion criteria were a diagnosis of OUD, participation in treatment/prenatal care program, and laboratory evaluation of HCV status. The primary exposure was the presence of HCV antibodies, and secondarily, a detectable viral load (viremia). The primary outcome was PTB, which was further classified as spontaneous or iatrogenic. Multivariable logistic regression was used to detect associations while adjusting for race, history of prior PTB, and tobacco use. A total of 941 individuals were included in the study, 404 with HCV and 537 without. Rates of PTB did not differ between those with compared to those without HCV (20.3 vs. 23.8%, adjusted odds ratio [aOR] = 0.75 [95% confidence interval (CI): 0.53-1.07]). There were similar rates of spontaneous PTB (13.1 vs. 16.2%, aOR = 0.79 [95% CI: 0.43-1.45]) and iatrogenic PTB (7.2 vs. 7.6%, aOR = 1.26 [95% CI: 0.69-2.30]). Comparing those with viremia to those without, there were also similar rates of overall PTB (21.6 vs. 17.9%, aOR = 0.86 [95% CI: 0.52-1.44]), spontaneous PTB (13.3 vs. 12.9%, aOR = 0.97 [95% CI: 0.52-1.87]), and iatrogenic PTB (8.3 vs. 5.0%, aOR = 1.83 [95% CI: 0.76-4.94]). HCV does not appear to be associated with spontaneous or iatrogenic PTB in pregnant persons with OUD who are engaged in treatment and prenatal care. The role of co-located multidisciplinary prenatal and addiction programs in the association between HCV and PTB warrants further investigation. · Hepatitis C antibodies are not associated with PTB in those with OUD.. · Hepatitis C viremia is not associated with PTB.. · Multidisciplinary treatment programs may contribute to these findings..

Association of maternal blood mercury concentration during the first trimester of pregnancy with birth outcomes.

Exposure to mercury has been associated with adverse effects on pregnancy outcomes. However, there is limited literature on mercury exposure and pregnancy outcomes in Chinese pregnant women. Our study was to investigate the possible association between maternal mercury exposure and spontaneous preterm birth and birth weight. This study was a nested case-control study. The association between blood mercury concentration and both spontaneous preterm birth and birth weight was analyzed using conditional logistic regression and linear regression adjusted for the potential confounding factors, respectively. The dose-response relationship between mercury concentration and birth outcomes was estimated using restricted cubic spline regression. The mean concentration of mercury was 2.8 ± 2.2µg/L. A positive relationship was observed between maternal blood mercury concentration and SPB when analyzed as a continuous variable. However, it was not found to be statistically significant (adjusted OR = 1.10, 95% CI = 0.95-1.26, P = 0.202). Moderate mercury exposure was associated with a higher risk of SPB (Q3 vs. Q1: crude OR = 2.50, 95% CI = 1.16-5.41, P = 0.02; adjusted OR = 3.49, 95% CI = 1.33-9.11, P = 0.011). After considering the combined effects of chemicals other than mercury exposure (including lead, selenium, and cadmium), the results remained consistent. There was no statistically significant association between blood mercury levels and birth weight (adjusted coefficient = 18.64, P-value = 0.075). There were no statistically significant dose-response associations between mercury concentration and birth outcomes (SPB: P = 0.076; birth weight: P = 0.885). Public health policies should focus on reducing environmental releases of mercury, improving food safety standards, and providing education to pregnant women about the risks of mercury exposure and preventive measures.

Low Levels of Complement Factor H in the First Trimester of Pregnancy Are Associated with Spontaneous Preterm Birth.

Preterm birth (PTB) remains a significant public health concern, and prediction is an important objective, particularly in the early stages of pregnancy. Many studies have relied on cervical characteristics in the mid-trimester, with limited results. It is therefore crucial to identify novel biomarkers to enhance the ability to identify women at risk. The complement pathway is implicated in the process of placentation, and recent proteomics studies have highlighted the potential roles of some complement proteins in the pathophysiology of PTB. To determine the association between the occurrence of spontaneous preterm birth (sPTB) and the concentration of complement C3, factor B, and factor H in the blood of pregnant women during the first trimester. This prospective cohort study included women with singleton pregnancies, both with and without a history of sPTB, from two health institutions in Bucaramanga, Colombia. The outcome was sPTB before 37 weeks. A blood sample was obtained between 11 + 0 to 13 + 6 weeks. ELISA immunoassay was performed to quantify the levels of C3, factor B, and factor H. A total of 355 patients were analyzed, with a rate of sPTB of 7.6% (27/355). The median plasma concentration for C3, factor B, and factor H were 488.3 μg/mL, 352.6 μg/mL, and 413.2 μg/mL, respectively. The median concentration of factor H was found to be significantly lower in patients who delivered preterm compared to patients who delivered at term (382 μg/mL vs. 415 μg/mL; p = 0.034). This study identified a significant association between low first-trimester levels of factor H and sPTB before 37 weeks. These results provide relevant information about a new possible early biomarker for sPTB. However, the results must be confirmed in different settings, and the predictive value must be examined.

The Association Between Maternal ABO Blood Group and the Occurrence of Spontaneous Preterm Birth: A Retrospective Population-Based Cohort Study.

There is limited and inconsistent evidence that imply a relationship between ABO blood types and rate of preterm birth (PTB). We aim to examine the association between maternal ABO blood group and PTB rate. A retrospective-study conducted at a university teaching institution on data collected between 2013 and 2019. Women who delivered a viable neonate at ≥ 24 weeks without major malformations were included. Indicated PTBs were excluded. PTB and early PTB were defined as deliveries that occurred < 37 and < 34 weeks respectively. PTB was further divided into 3 subgroups according to etiology: membranes rupture, intact membranes, and placental abruption regardless of membranes' status. The primary outcome was spontaneous PTB rate. Of 19,301 women included, PTB and early PTB rates were 7.3% (1,418/19,301) and 2.3% (440/19,301) respectively. Rates of PTB in blood groups A, B, O, and AB, were 7.3%, 6.9%, 7.5%, and 7.5% respectively (p = 0.68). There was no significant difference according to etiology. Rates of early PTB were also comparable (p = 0.63). After adjustment for demographic and obstetric variables, blood type was associated with increased placental abruption rate among women who had early PTB (p = 0.038). Placental abruption rate was significantly higher in group A (22.5%) compared to group B (14.1%), (adjusted p = 0.04) and group O (14.0%), (adjusted p = 0.01). The rate in group AB was 17.1%, (adjusted p = 0.85). In conclusion, no association was found between a particular blood group and PTB rate. Women with group A, admitted in early PTB, had an increased risk that the underlying etiology was placental abruption.

Transabdominal-transvaginal ultrasound cervical length sequential screening to predict the risk of spontaneous preterm birth in singleton pregnancy women with low risk of preterm birth

Objective: To investigate the feasibility of predicting the risk of spontaneous preterm birth in singleton pregnancy women with low risk of preterm birth by transabdominal-transvaginal ultrasound cervical length sequential screening in the second trimester. Methods: This prospective longitudinal cohort study included singleton pregnant women at 11-13+6 gestational weeks who were admitted to Nanjing Drum Tower Hospital from January 2023 to September 2023. Transabdominal and transvaginal cervical lengths were measured during the mid-trimester fetal ultrasound scan at 18-24 weeks, and pregnancy outcomes were obtained after delivery. A short cervix was defined as a transvaginal cervical length of ≤25 mm, and the outcomes were defined as spontaneous preterm birth occurs between 20 and 36+6 weeks and extremely preterm birth before 32 weeks. The area under the receiver operating characteristic (ROC) curve was used to evaluate the effectiveness of predicting spontaneous preterm birth by transabdominal and transvaginal cervix length, as well as the effectiveness of predicting short cervix by transabdominal cervical length. The relationship between transabdominal and transvaginal cervical length was evaluated using a scatter plot. Results: A total of 562 cases were included in this study, comprising 33 cases of spontaneous preterm birth (7 cases occurring before 32 weeks) and 529 cases of term birth. (1) Compared to the term birth group, transabdominal cervical length (median: 37.6 vs 33.2 mm; Z=-3.838, P<0.001) and transvaginal cervical length (median: 34.0 vs 29.9 mm, Z=-3.030, P=0.002) in the spontaneous preterm birth group were significantly shorter. (2) The areas under the ROC curve for predicting spontaneous preterm birth by transabdominal and transvaginal cervical length were 0.699 (95%CI: 0.588-0.809) and 0.657 (95%CI: 0.540-0.774), respectively. The sensitivity, specificity and positive predictive value of transvaginal cervical length Conclusions: In singleton pregnancy women with low risk of preterm birth, transabdominal-transvaginal cervical length sequential screening can reduce unnecessary transvaginal ultrasounds by approximately 41% without missing the diagnosis of pregnant women with a short cervix. This method also enhances the effectiveness of transvaginal cervical length to spontaneous preterm birth.

Effects of nationwide adjustment of tocolysis protocol in the Netherlands on neonatal outcomes in women with threatened preterm birth and delivery at 30-32 weeks of gestation: A cohort study

ObjectiveIn 2019 the Dutch national prevention of preterm birth (PTB) protocol was adjusted to withhold tocolysis for threatened PTB above 30 weeks of gestation due to insufficient evidence regarding its effectiveness on improving perinatal outcomes. The aim of this study is to evaluate neonatal outcomes of children born in the Netherlands between 30 and 32 weeks of gestation before and after the national protocol change. Study designWe performed a nationwide retrospective cohort study comparing outcomes of births in the years 2018 (tocolysis) and 2020 (no tocolysis). Tocolytic therapy consisted of either nifedipine or atosiban. Data were extracted from the national Perinatal Registry (PERINED). Women with a spontaneous PTB from 30 + 0 to 31 + 6 weeks of gestation were included. The primary outcome was a composite of mortality, severe intraventricular hemorrhage, severe necrotizing enterocolitis, cystic periventricular leukomalacia, and retinopathy of prematurity needing therapy. Secondary outcomes included additional neonatal outcomes. The odds ratio (OR) with corresponding 95 % confidence interval (CI) was calculated by logistic regression analysis for the year 2020 compared with 2018. ResultsComposite neonatal outcome did not differ between 2018 compared to 2020 (8.4 % (18/215) vs 8.2 % (25/306), OR 0.95; 95 % CI 0.51–1.77). No difference in composite neonatal outcome was found when analyzing groups as singletons (7.1 % vs 9.3 %, OR 1.35; 95 % CI 0.64–2.87), and multiples (13.3 % vs 5.9 %, OR 0.41; 95 % CI 0.13–1.26). ConclusionThere was no significant difference in composite neonatal outcome in pregnancies resulting in spontaneous PTB between 30 and 32 weeks of gestation in 2018 (with tocolysis) compared to 2020 (no tocolysis). These results support the protocol adjustment to withhold tocolytic treatment in women with threatened PTB above 30 weeks of gestation.

Gestational urinary concentrations of glyphosate and aminomethylphosphonic acid in relation to preterm birth: the MIREC study.

Few high-quality studies have evaluated associations between urinary glyphosate or its environmental degradate (aminomethylphosphonic acid (AMPA)] and preterm birth (PTB). To quantify associations between urinary glyphosate and AMPA and preterm birth in the pan-Canadian Maternal-Infant Research on Environmental Chemicals (MIREC) study and determine if associations differ by fetal sex. We measured first trimester urinary glyphosate and AMPA concentrations in MIREC participants who were recruited between 2008-2011 from 10 Canadian cities. Of the 1880 participants whose first trimester urine samples were analyzed for glyphosate or AMPA, 1765 delivered a singleton, live birth. Our primary outcome was preterm birth (PTB) defined as births occurring between 20 and <37 weeks. Secondary outcomes were spontaneous preterm births (sPTB) and gestational age. We modelled the hazard of PTB and sPTB using discrete time survival analysis with multivariable logistic regression to calculate odds ratios (OR). We used multivariable linear regression models to quantify associations between analytes and gestational age. To assess effect modification by fetal sex, we stratified all models and calculated interaction terms. In the logistic regressions models we additionally calculated the relative excess risk due to interaction. Six percent (n = 106) of the study population delivered preterm, and 4.7% (n = 83) had a spontaneous preterm birth. Median specific-gravity standardized concentrations of glyphosate and AMPA were 0.25 and 0.21 µg/L. Associations between both glyphosate or AMPA and PTB, sPTB, and gestational age centered around the null value. The adjusted ORs of PTB for each doubling of glyphosate and AMPA concentrations were 0.98 (95% CI: 0.94, 1.03) and 0.99 (95% CI: 0.92, 1.06) respectively. We observed no evidence of differences by fetal sex. In this Canadian pregnancy cohort, neither glyphosate nor AMPA urinary concentrations was associated with PTB or reduced gestational length.