Risk Factors For Preterm Birth Research Articles

The effect of histological and subclinical chorioamnionitis and funisitis on breathing effort in premature infants at birth: a retrospective cohort study

Antenatal inflammation in the form of chorioamnionitis (fetal membranes; HCA) and funisitis (umbilical vessels; FUN) is a major risk factor for preterm birth. Exposure to HCA + FUN affects infants by releasing mediators that may suppress respiratory drive. While the association between clinical chorioamnionitis (CCA) and (depressed) spontaneous breathing has been described, we have investigated the association between breathing and HCA + FUN. Infants born < 30 weeks’ gestation with available placental pathology assessments were included. Infants were compared at multiple levels: infants with vs without HCA + FUN (comparison 1) and infants with subclinical HCA + FUN vs infants without any chorioamnionitis (comparison 2). The primary outcome was breathing effort, defined as minute volume (MV) of spontaneous breathing in the first 5 min after birth. We also assessed tidal volume (Vt), respiratory rate (RR), heart rate (HR), oxygen saturation (SpO2) and oxygen requirement (FiO2). Regression analyses were performed to control for confounding factors. One hundred eighty-six infants were included (n = 75 infants with HCA + FUN vs. n = 111 infants without HCA + FUN). Comparison 1: Infants with HCA + FUN had lower gestational ages 26+5 (25+0–28+1; median (IQR) and lower birthweights (mean ± SD; 943 ± 264) compared to infants without HCA + FUN (28+4 (27+0–29+1) weeks, p < 0.001 and 1023 ± 270 g, p = 0.049). Comparison 2: Subclinical HCA + FUN was diagnosed in 46/75 HCA + FUN infants. Infants with subclinical HCA + FUN had lower gestational ages (26+6 (25+1–28+3) vs. 28+4 (27+2–29+1) weeks, p < 0.001) without significant differences for birthweights (987 ± 248 vs. 1027 ± 267 g, p = 0.389) compared to infants without any chorioamnionitis (n = 102 infants). After adjustment, HCA + FUN was associated with lower MV (p = 0.025), but subclinical HCA + FUN was not (p = 0.226). HCA + FUN and subclinical HCA + FUN were associated with lower Vt (p = 0.003; p = 0.014), SpO2 at 5 min (p = 0.021; 0.036) and SpO2/FiO2 ratio (p = 0.028; p = 0.040).Conclusion: HCA + FUN and subclinical HCA + FUN are associated with reduced oxygenation and parameters that reflect breathing effort in premature infants at birth.What is Known:• Acute antenatal inflammation, in the form of chorioamnionitis (fetal membranes) and funisitis (umbilical vessels), affects a large proportion of premature infants.• Clinical chorioamnionitis is associated with reduced breathing effort and oxygenation in premature infants at birth.What is New:• Histological and subclinical chorioamnionitis and funisitis are associated with reduced breathing effort parameters and oxygenation in premature infants at birth.

Secular variation and risk factors of preterm birth in Hainan, the Free Trade Port in China from 2010 to 2021

ObjectivesPreterm delivery rates have increased obviously worldwide over the past decade, yet reliable epidemiological studies on the incidence of preterm birth and temporal trends are not available in Hainan, The Free Trade Port in China. We aimed to describe the rate of preterm birth and trends between 2010 and 2021 and to primarily explore risk factors associated with preterm birth in Hainan, China.MethodsThis was an observational study was based on data from the Hainan Provincial Birth Certificate System (HPBCS) for live births between 1 January 2010 and 31 December 2021. We included pregnancies resulting in at least one live birth, with newborns born at a gestational age of 28 weeks or greater, or with a birth weight of 1000 g or more. The outcome were preterm birth rates and their trends over time. Potential risk factors were collected, including infant gender, maternal age, paternal age, maternal ethnicity, paternal ethnicity, home address, and single or multiple pregnancies. The logistic regression model was used to assess the relationship between preterm birth and potential risk factors.ResultsA total of 1,537,239 live births and 86,328 preterm births were investigated, giving a total preterm birth rate of 5.62%. The overall preterm birth rate increased from 4.47% in 2010 to 7.12% in 2021 (compound annual growth rate [CAGR] 4.32). The CAGR of late preterm birth is consistent with the overall preterm birth rate (4.32%). The fastest growth is observed in the rate of very preterm births (5.53%), while the rate of moderate preterm births exhibits the slowest growth (3.87%). Infant gender, multiple pregnancy, home address, parental age, and ethnicity had significant effects on preterm birth.ConclusionThe preterm birth rate was increasing year by year from 2010 to 2021 in Hainan, The Free Trade Port in China. Incidence of preterm births in Hainan Province in relation to multiple pregnancies, infant sex, parental age, parental race and residential address.

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.

Association Between Maternal Cytomegalovirus Seropositivity, Preterm Birth, and Preeclampsia in Two Cohorts From Quebec, Canada: A Mediation Analysis.

Preterm birth and preeclampsia significantly contribute to infant morbidity and mortality, posing critical public health concerns. Viral infections, particularly Cytomegalovirus (CMV), associated with chronic inflammation, may play a role in these adverse pregnancy outcomes. The contribution of CMV to preterm birth and preeclampsia requires further investigation. Data from 6048 pregnant women from two prospective Quebec cohorts, recruited between May 2005 and August 2012, were analyzed. First-trimester CMV serology was the exposure variable. Associations were assessed using multivariable logistic regression adjusted by inverse probability treatment weighting (IPTW) of propensity scores. Mediation analyses estimated the direct effect of maternal CMV serostatus on preterm birth, excluding mediation by preeclampsia. Preterm birth and preeclampsia proportions were 5.1% (95% CI: 4.6-5.7) and 1.9% (95% CI: 1.6-2.3), respectively. Multivariable logistic regression adjusted by IPTW showed associations between CMV seropositivity and preterm birth (OR 1.20, 95% CI: 1.02-1.41) and CMV seropositivity and preeclampsia (OR 1.41, 95% CI: 1.08-1.84). Mediation analysis indicated that 97% of the total effect of CMV seropositivity on preterm birth is direct, with the remaining 3% mediated by preeclampsia. CMV seropositivity appears to be a risk factor for both preterm birth and preeclampsia. The effect of maternal CMV seropositivity on preterm birth is primarily direct, not mediated by preeclampsia. Future studies should explore the impact of preventive measures against CMV infection on the incidence of preterm delivery and preeclampsia.

Epstein–Barr Virus as a Risk Factor for Fetal Hypoxia and Preterm Birth: A Case Report

Epstein–Barr Virus as a Risk Factor for Fetal Hypoxia and Preterm Birth: A Case Report

Mental health concerns during pregnancy associated with the risk of preterm birth: A retrospective cohort study

BackgroundsThere are multiple risk factors for preterm birth (PTB), one of the most important of which is mood disorders during pregnancy. We aimed to comprehensively investigate the association of both total mental health concerns and ten specific psychiatric symptoms with PTB risk. MethodsA cohort study was performed consisting of 25,175 pregnant women who participated in Women and Children's Hospital of Chongqing Medical University between 2020 and 2022. The Symptom Checklist 90 (SCL-90) was utilized to assess the psychiatric symptoms. Multivariable or multinomial logistic regression was applied to investigate mental health concerns associated with risk of PTB or its different clinical sub-categories, respectively. Sensitivity analyses were further performed to validate the results. Results8336 women who met the inclusion criteria were included; of these, 547 (6.6 %) had preterm deliveries, and 2542 (30.5 %) had mental health concerns. Compared with women with healthy minds, women with total mental health concerns had a 29.0 % higher risk of overall PTB (OR = 1.28, 95%CI = 1.07–1.54), medical-induced PTB (OR = 1.49, 95%CI = 1.05–2.13) and spontaneous PTB with premature rupture of membranes (OR = 1.33, 95%CI = 1.01–1.74). As to the specific psychological symptoms, hostility pregnant women had a 55.0 % higher risk of PTB (OR = 1.55, 95%CI = 1.14–2.11). Similar results were observed in most of the sensitivity analyses. LimitationsThis is a single-center study, thus the extrapolation of the results may be limited. ConclusionsPregnant women with mental health symptoms, especially hostility, have an increased risk of PTB. The findings underscore that integrating mental health services into routine maternal care may be a strategy to prevent PTB.

Risk and Protective Factors for Preterm Birth Among Racial, Ethnic, and Socioeconomic Groups in California

Preterm birth (PTB) (gestational age <37 weeks) is a major cause of infant mortality and morbidity in the US and is marked by racial and ethnic and socioeconomic inequities. Further research is needed to elucidate the association of risk and protective factors with trends in PTB rates and with related inequities. To describe the association of PTB rates with inequities as well as related risk and protective factors over the past decade in a US population-based cohort. This retrospective cohort study of singleton live births in California from January 1, 2011, to December 31, 2022, was conducted using vital statistics records and hospital records. The cohort included births with a gestational age of 22 to 44 weeks. Preterm birth rates by racial and ethnic group and by public and nonpublic insurance (considered as a proxy for socioeconomic status) were studied across years. Log-linear regression (relative risks with 95% CIs) was used to evaluate risk and protective factors within groups. Associations of PTB rates with risk and protective factors were assessed. This study included 5 431 018 singleton live births to individuals who identified as American Indian or Alaska Native (0.3%), Asian (14.2%), Black (4.9%), Hispanic (47.8%), or White (27.0%). A total of 43.1% of births were to individuals with public health insurance. From 2011 to 2022, the overall PTB rate increased from 6.8% to 7.5% (change [SE], 10.6% [0.6%]; z score of 18.5; P < .001). Differences in PTB rates and associated changes were observed for racial and ethnic groups and insurance groups. For example, 2022 PTB rates ranged from 5.8% among White individuals with nonpublic insurance to 11.3% among Black individuals with public health insurance. From 2011 to 2022, PTB rates decreased from 9.1% to 8.8% (change [SE], -3.5% [4.2]; z score of -0.8; P = .42) among Black individuals with nonpublic insurance, whereas they increased from 6.4% to 9.5% (change [SE], 49.8% [16.0%]; z score of 3.1; P = .002) among American Indian or Alaska Native individuals with nonpublic insurance. Increases in some risk factors (eg, preexisting diabetes, sexually transmitted infections, mental health conditions) were observed in most groups, and decreases in some protective factors (eg, participation in the California Women, Infants, and Children program) (P for trend < .001 from 2011 to 2021) were observed mostly in low-income groups. In this cohort study of singleton live births in California, PTB rates increased in many groups. Persistent racial and ethnic and socioeconomic inequities were also observed. Changes in risk and protective factors provided clues to patterns of PTB. These data point to an urgent need to address factors associated with PTB at both the individual and population levels.

Timing of Antidepressant Use in Pregnancy and Preterm Birth

OBJECTIVE: To evaluate the implication of timing of antidepressant exposure on preterm birth to better guide clinical counseling. DATA SOURCES: A systematic review and meta-analysis was conducted following PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines, using PubMed, MEDLINE Complete, EBSCO, CINAHL Plus, and ClinicalTrials.gov along with a manual search of references in relevant publications. The databases were searched between January 2000 and December 2022 with the following keywords: antidepressants, antidepressant medication, SSRI, selective serotonin reuptake inhibitors, TCA, or SNRI AND pregnancy, pregnant, prenatal, antenatal, perinatal, maternal AND trimester or timing AND preterm or premature. METHODS OF STUDY SELECTION: The database search resulted in 162 studies. The 13 studies that met inclusion criteria compared preterm birth rates in pregnant patients exposed to antidepressants at a specified time in pregnancy (early, late, or throughout pregnancy) and a control group. Covidence was used for screening and data extraction. Excel and R were used for tabulation and statistical analysis, respectively. TABULATION, INTEGRATION, AND RESULTS: Of the 13 studies, nine measured preterm birth rates with antidepressant use in early pregnancy, 10 in late pregnancy, and four throughout pregnancy. Separate random effects models were used to synthesize the effect sizes from studies that did not adjust for presence of maternal depression in the study sample and those that did. In each model, subgroup analysis was conducted to assess the effect of timing of antidepressant exposure on the odds of preterm birth. In the model unadjusted for depression, pooled odds ratios (ORs) for the association between use of antidepressants and preterm birth were 1.41 (95% CI, 1.10–1.81) in early pregnancy, 1.51 (95% CI, 1.26–1.82) in late pregnancy, and 2.79 (95% CI, 1.27–6.12) throughout pregnancy. After adjusting for depression, the pooled ORs were 1.04 (95% CI, 0.83–1.31) in early pregnancy, 1.26 (95% CI, 0.95–1.66) in late pregnancy, and 1.79 (95% CI, 0.54–5.91) throughout pregnancy. No significant effect of timing was found in either model. CONCLUSION: Antidepressant use in pregnancy was not associated with preterm birth, regardless of timing of use. Pregnant patients with an established diagnosis of depression should receive individualized counseling regarding antidepressant use while taking into consideration their risk factors for preterm birth and the implications of untreated depression. SYSTEMATIC REVIEW REGISTRATION: PROSPERO, CRD42023390136.

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

ObjectiveThis 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. MethodsThis 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. ResultsFollowing 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. ConclusionsThe 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.

The intergenerational association of preterm birth: A systematic review and meta-analysis.

Around half of preterm births lack identifiable causes, indicating the need for further investigation to understand preterm birth risk factors. Existing studies on the intergenerational association of preterm birth showed inconsistency in effect size and direction. This systematic review and meta-analysis aimed to review existing studies and provide comprehensive evidence on the intergenerational association of preterm births. We searched MEDLINE, Embase and Maternity and Infant Care databases, from the inception of each database to 04 April 2024. Eligibility criteria included studies that reported on women who had given birth and had recorded information about a family history of preterm birth in one or both of the child's biological parents. Data were extracted by two independent reviewers. A random-effects model was used to compute pooled estimates using odds ratios. Sixteen eligible studies with a total of 2 271 612 mothers were included. The findings indicated a 1.44 (OR = 1.44, 95% CI: 1.34, 1.54) fold increase in odds of giving preterm births among women who were born preterm. Additionally, having a sibling born preterm (OR = 1.53, 95% CI: 1.24, 1.87) and having a partner born preterm (OR = 1.12, 95% CI: 1.01, 1.25) were associated with increased likelihood of giving preterm births among women. The study revealed that women with a family history of preterm birth face an increased risk of giving preterm births. Screening pregnant women for a family history of preterm birth is essential, with those having a positive family history requiring closer follow-up.

Implementation of a treatment bundle for risk factors for spontaneous preterm birth - Preliminary results

Implementation of a treatment bundle for risk factors for spontaneous preterm birth - Preliminary results

The Influence of Dental Status and Blood Parameters Characterizing Endogenous Intoxication on the Timing of Childbirth.

Background and Objectives: Epidemiological and microbiological-immunological studies have led to the conclusion that periodontal disease may be a risk factor for preterm birth. The aim of this study was to investigate and identify the relationship of some hematological cellular biomarkers characterizing the chronic oral focus of infection with pregnancy outcomes and their impact on those outcomes. Materials and Methods: Clinical and laboratory tests were conducted on 100 pregnant women, grouped by full-term or preterm births, with the assessment of the following markers: DMF, CPI and PIRI, PHP, microbiological examination of periodontal pockets and amniotic fluid, WBS count, WBCSI, LGI, and NMR. A statistical analysis was carried out with SPSS Statistics version 19.0. Results: Women with preterm labor had higher-grade caries (CSL > 0.3), while women with full-term childbirth had moderate caries (CSL < 0.3). A satisfactory level of oral hygiene efficiency was found in 50% (group 1) and 38.1% (group 2) of the expectant mothers. The periodontal status by the PIRI showed tissue lesions in 20.7% (group 1) and 92.9% (group 2) of the women. The WBCSI was 2.27 ± 0.82 and 2.15 ± 0.68, the NMR was 9.29 ± 5.119 and 11.62 ± 7.78, and the LGI was 3.54 ± 1.1 and 3.73 ± 0.81 in groups 1 and 2, respectively. Comparative analysis of bacterial contamination of the amniotic fluid revealed the predominance of Fusobacterium nucleatum (64.3%), Tannerella forsythia (57.1%), Prevotella intermedia (50%), Porphyromonas gingivalis (57.1%), Staphylococcus aureus (45.2%), and Candida albicans (50%) in women with premature birth. Conclusions: In women with preterm birth, the values of the indices characterizing a chronic oral focus of infection evoke more significant correlations with the timing of delivery, which indicates the significant role of an oral focus of infection. The presence of microbial invasion of amniotic fluid may indicate the role of periodontopathogenic bacteria in pregnant women diagnosed with a risk of preterm birth.

Uterocervical angle and cervical length measurements for spontaneous preterm birth prediction in low-risk singleton pregnant women: a prospective cohort study.

Preterm birth is the leading cause of early neonatal morbidity and mortality. Strategies to predict preterm birth risk can help improve pregnancy outcomes. Even pregnant women without known risk factors for preterm birth can also experience it. This study aimed to evaluate the ability of the uterocervical angle and cervical length to predict spontaneous preterm birth in low-risk singleton pregnant women. A prospective study on 1107 singleton pregnant women between 16+0 and 23+6weeks gestation at low risk for spontaneous preterm birth who were treated at the Haiphong Hospital of Obstetrics and Gynecology, Vietnam, between September 2020 and September 2021 was conducted. A single sonographer assessed the cervical length and the uterocervical angle using transvaginal ultrasonography. The patients were followed up until delivery to determine the main pregnancy outcome (spontaneous preterm birth before 37weeks gestation). The cut-off points for the uterocervical angle and cervical length were established by analyzing the receiver operating characteristic curve. The sensitivity, specificity, likelihood ratio, positive and negative predictive values, and accuracy of the uterocervical angle and cervical length for predicting spontaneous preterm birth were determined. A uterocervical angle ≥ 99° predicted spontaneous preterm birth at < 37weeks, with a sensitivity and specificity of 91% and 76%, respectively. A cervical length ≤ 33.8mm predicted preterm birth at < 37weeks with a sensitivity and specificity of 25% and 66%, respectively. A uterocervical angle ≥ 99° combined with a cervical length ≤ 33.8mm yielded the sensitivity, specificity, positive predictive value, likelihood ratio, and accuracy of spontaneous preterm birth prediction of 66%, 93%, 36%, 9, and 91%, respectively; thus provided a significant increase of specificity with an acceptable reduction of sensitivity as compared to cervical length alone. Besides the cervical length, the uterocervical angle can be considered a valuable ultrasound parameter for predicting spontaneous preterm birth in low-risk singleton pregnant women. Combining the uterocervical angle and cervical length yielded stronger spontaneous preterm birth prediction values.

Assessment of obstetric history and cervical length as risk factors for preterm birth

Assessment of obstetric history and cervical length as risk factors for preterm birth

Comparing cervical cerclage, pessary and vaginal progesterone for prevention of preterm birth in women with a short cervix (SuPPoRT): A multicentre randomised controlled trial.

Cervical cerclage, cervical pessary, and vaginal progesterone have each been shown to reduce preterm birth (PTB) in high-risk women, but to our knowledge, there has been no randomised comparison of the 3 interventions. The SuPPoRT "Stitch, Pessary, or Progesterone Randomised Trial" was designed to compare the rate of PTB <37 weeks between each intervention in women who develop a short cervix in pregnancy. SuPPoRT was a multicentre, open label 3-arm randomised controlled trial designed to demonstrate equivalence (equivalence margin 20%) conducted from 1 July 2015 to 1 July 2021 in 19 obstetric units in the United Kingdom. Asymptomatic women with singleton pregnancies with transvaginal ultrasound cervical lengths measuring <25 mm between 14+0 and 23+6 weeks' gestation were eligible for randomisation (1:1:1) to receive either vaginal cervical cerclage (n = 128), cervical pessary (n = 126), or vaginal progesterone (n = 132). Minimisation variables were gestation at recruitment, body mass index (BMI), and risk factor for PTB. The primary outcome was PTB <37 weeks' gestation. Secondary outcomes included PTB <34 weeks', <30 weeks', and adverse perinatal outcome. Analysis was by intention to treat. A total of 386 pregnant women between 14+0 and 23+6 weeks' gestation with a cervical length <25 mm were randomised to one of the 3 interventions. Of these women, 67% were of white ethnicity, 18% black ethnicity, and 7.5% Asian ethnicity. Mean BMI was 25.6. Over 85% of women had prior risk factors for PTB; 39.1% had experienced a spontaneous PTB or midtrimester loss (>14 weeks gestation); and 45.8% had prior cervical surgery. Data from 381 women were available for outcome analysis. Using binary regression, randomised therapies (cerclage versus pessary versus vaginal progesterone) were found to have similar effects on the primary outcome PTB <37 weeks (39/127 versus 38/122 versus 32/132, p = 0.4, cerclage versus pessary risk difference (RD) -0.7% [-12.1 to 10.7], cerclage versus progesterone RD 6.2% [-5.0 to 17.0], and progesterone versus pessary RD -6.9% [-17.9 to 4.1]). Similarly, no difference was seen for PTB <34 and 30 weeks, nor adverse perinatal outcome. There were some differences in the mild side effect profile between interventions (vaginal discharge and bleeding) and women randomised to progesterone reported more severe abdominal pain. A small proportion of women did not receive the intervention as per protocol; however, per-protocol and as-treated analyses showed similar results. The main study limitation was that the trial was underpowered for neonatal outcomes and was stopped early due to the COVID-19 pandemic. In this study, we found that for women who develop a short cervix, cerclage, pessary, and vaginal progesterone were equally efficacious at preventing PTB, as judged with a 20% equivalence margin. Commencing with any of the therapies would be reasonable clinical management. These results can be used as a counselling tool for clinicians when managing women with a short cervix. EU Clinical Trials register. EudraCT Number: 2015-000456-15, clinicaltrialsregister.eu., ISRCTN Registry: ISRCTN13364447, isrctn.com.

Routine transabdominal cervical length screening in mid-pregnancy for the prevention of preterm birth: Is it good enough to use as a screening test?

Preterm birth (PTB) is a major pregnancy complication. There is evidence that a short cervical length in mid-pregnancy may predict women at increased risk of PTB. To evaluate the utility of population-based, transabdominal cervical length (TACL) measurement screening in mid-pregnancy for PTB prediction in women. A transabdominal approach was initially performed, with a transvaginal (TVCL) approach offered when the TACL was <35 mm, could not be accurately measured, or the pregnancy had risk factors for PTB. TACL was compared to the directly related TVCL, when both were performed at the same assessment. Women with risk factors of PTB were included when they had both TACL and TVCL measurements performed at the same visit. Data were provided for 9355 singleton pregnancies from 13 participating imaging centres. A transabdominal approach was used in 9006 (96.3%), including 682 (7.3%) TVCL combined with TACL. There were 349 (3.7%) women who had TVCL only. The median TACL was longer (40 mm) than the TVCL (38 mm). In 682 paired TACL and TVCL measurements, TACL <35 mm correctly identified 96.2% of pregnancies with TVCL <25 mm, compared with 65.4% of cases when using a TACL <30 mm. A TVCL <25 mm occurred in 59 (0.6%) women. A TACL <35 mm was associated with birth <37 weeks of gestation in 12.1% of women and birth <32 weeks of gestation in 3.9%. Universal TACL is a feasible option for population screening of cervical length in a low-risk population, progressing to TVCL if the TACL is <35 mm or the cervix cannot be transabdominally accurately measured.

Diabetes Mellitus as a Risk Factor for Spontaneous Preterm Birth in Women with a Short Cervix after Ultrasound-Indicated Cerclage.

Background: Preterm birth (PTB) is a significant challenge in contemporary obstetrics, affecting over one in ten infants worldwide and accounting for 75% of perinatal mortality. Short cervical length during mid-trimester is well known to be associated with an increased risk of spontaneous preterm birth (sPTB). Ultrasound-indicated cerclage (UIC) is recommended to prevent sPTB in women with a short cervix at mid-trimester and a history of sPTB. Objectives: This retrospective observational study aimed to examine the impact of diabetes and obesity on the occurrence of sPTB in women who underwent UIC due to mid-trimester cervical shortening. Methods/Results: The analysis revealed that cervical length at the time of operation, preoperative erythrocyte sedimentation rate levels, and diabetes were independent risk factors for sPTB. Additionally, the presence of diabetes, particularly when combined with obesity, significantly elevated the risk of sPTB. Women with pregestational diabetes or those requiring insulin treatment had a higher propensity for preterm delivery compared to those with gestational diabetes managed through diet control alone. Conclusions: These findings emphasize the importance of considering maternal metabolic factors, such as diabetes and obesity, in women with a short cervix when planning for UIC and highlight the crucial role of optimizing maternal glucose control and weight management in reducing the risk of sPTB.

The relationship between air pollutants and preterm birth and blood routine changes in typical river valley city

ObjectiveTo collect maternal maternity information on preterm births in two tertiary hospitals in the urban area of Baota District, Yan'an City, from January 2018 to December 2020, to explore the long-term and short-term effects of air pollutants (PM2.5, PM10, SO2, NO2, CO and O3) and preterm births, and to explore changes in blood cell counts due to air pollutants.MethodsDaily average mass concentration data of six air pollutants in the urban area of Yan'an City from January 1, 2017 to December 31, 2020 were collected from the monitoring station in Baota District, Yan'an City. Meteorological information was obtained from the Meteorological Bureau of Yan'an City, including temperature,relative humidity and wind speed for the time period. The mass concentration of air pollutants in each exposure window of pregnant women was assessed by the nearest monitoring station method, and conditional logistic regression was used to analyze the relationship between air pollutants and preterm births, as well as the lagged and cumulative effects of air pollutants. Multiple linear regression was used to explore the relationship between air pollutants and blood tests after stepwise linear regression was used to determine confounders for each blood test.ResultsThe long-term effects of pollutants showed that PM2.5, PM10, SO2, NO2and CO were risk factors for preterm birth. In the two-pollutant model, PM2.5, PM10, SO2 and NO2 mixed with other pollutants were associated with preterm birth. The lagged effect showed that PM2.5, PM10, SO2, NO, and CO were associated with preterm birth; the cumulative effect showed that other air pollutants except O3 were associated with preterm birth. The correlation study between air pollutants and blood indicators showed that air pollutants were correlated with leukocytes, monocytes, basophils, erythrocytes, hs-CRPand not with CRP.ConclusionExposure to air pollutants is a risk factor for preterm birth. Exposure to air pollutants was associated with changes in leukocytes, monocytes, basophils and erythrocytes and hs-CRP.

Pregnancy and Preterm Birth: A Systematic Review of Risk Factors and Prevention

Purpose: This systematic literature review aims to examine the multifaceted risk factors contributing to preterm birth and evaluate the effectiveness of various prevention strategies. By synthesizing existing research, the study seeks to provide a comprehensive understanding of the biological, behavioral, and socio-economic determinants of preterm birth and identify gaps for future research.. Research Design and Methodology: A qualitative approach was utilized, involving a systematic search of electronic databases to gather relevant peer-reviewed articles, systematic reviews, and meta-analyses published between 2000 and 2024. The study employed thematic analysis to identify key themes related to preterm birth risk factors and prevention strategies, incorporating approximately 150 high-quality studies into the synthesis. Findings and Discussion: The review identified critical biological factors such as maternal age and genetic predispositions, with younger and older mothers facing increased risks due to complications like cervical insufficiency and chronic conditions. Inflammatory pathways, hormonal regulation, and uteroplacental blood flow emerged as significant mechanisms leading to preterm labor. Behavioral factors, including smoking and substance abuse, along with poor nutritional status, exacerbated the risk. The discussion highlights the necessity for integrative prevention strategies that address these diverse factors through medical, behavioral, and socio-economic interventions. Implications: The findings underscore the importance of personalized medical care, comprehensive public health strategies, and policy initiatives to reduce preterm birth rates. Future research should focus on integrative models of care and personalized prevention approaches, considering the complex interplay of risk factors identified.

Effects of Pregnancy-Onset Asthma on Perinatal Outcomes: A Retrospective Cohort Study

BackgroundIt is unknown whether women with pregnancy-onset asthma are predisposed to worse pregnancy outcomes compared to women with pre-pregnancy asthma. ObjectiveTo explore whether pregnancy-onset asthma leads to worse perinatal outcomes compared with pre-pregnancy asthma. MethodsWomen who were discharged with a diagnosis of asthma and gave birth to a live singleton were included in this retrospective cohort analysis. Women were separated into groups based on whether the asthma was diagnosed during or before pregnancy. Clinical characteristics, perinatal outcomes, and asthma exacerbations (AE) between the two groups were compared. Results335 women were included in this study, of whom 39 (11.6%) had pregnancy-onset asthma and 296 had pre-pregnancy asthma. All the pregnant women in the pregnancy-onset group experienced asthma exacerbations (AE) during pregnancy. The proportion of chronic hypertension, chronic hypertension with superimposed preeclampsia, and spontaneous preterm births in the pregnancy-onset group was significantly higher than that in the pre-pregnancy asthma group. After adjusting for age, BMI, onset of asthma during pregnancy, and severity of AE through multivariate analysis, pregnancy-onset asthma was an independent risk factor for spontaneous preterm birth (aOR 7.71, 95% CI 1.30–46.12), severe AE was an independent risk factor for gestational hypertension and preeclampsia (aOR 3.58, 95% CI 1.30–9.87). ConclusionsDuring pregnancy, pregnancy-onset asthma in women is associated with an exacerbation of the condition. Obstetricians should be vigilant for signs of asthma onset during pregnancy. Other health-care providers should watch out for symptoms of gestational hypertension and preeclampsia in pregnant women with pre-existing or new-onset asthma.