Etiologically Based Functional Taxonomy of the Preterm Birth Syndrome

Mapping genetic susceptibility to spontaneous preterm birth: analysis of Utah pedigrees to find inherited genetic factors

BACKGROUND

Spontaneous preterm birth (SPTB) is the leading cause of neonatal morbidity and mortality. It is a final common pathway for multiple etiologies, some of which are well known while others likely remain to be identified. Despite recent advancements in identifying genetic risk factors, the mechanisms of many SPTBs remain poorly understood due to the phenotypic heterogeneity and complexity. Large family-based studies decrease heterogeneity and improve power to identify genetic causes of SPTB.

OBJECTIVE

To identify inherited genetic factors in SPTB etiology using large families.

STUDY DESIGN

Using the Utah Population Database, which links a 4.5 million-person genealogy to state birth certificate and fetal death records, we identified large pedigrees containing multiple women with early SPTB (<34 weeks' gestation) and any SPTB (<37 weeks' gestation). We reviewed birth certificate data to exclude those with maternal and fetal diagnoses associated with iatrogenic preterm birth, resulting in 74 large multiplex pedigrees for early SPTB. Enrolled women with SPTB underwent comprehensive clinical phenotyping with review of primary medical records. Seven pedigrees, each containing at least 3 sampled women with SPTB, were the focus of this genetic study. High-density single-nucleotide polymorphism genotyping was conducted in maternal peripheral blood samples from women in the seven pedigrees. Shared genomic segments analysis was performed to identify genome-wide significant chromosomal regions shared in excess by women with SPTB.

RESULTS

We identified two genome-wide significant chromosomal regions. In single-pedigree SGS analysis, a 1.75 Mega base region in chromosome 8 (8q24.23) was shared by 5 out of 6 women with SPTB in a single large pedigree (false positive rate=0.028). In duo-pedigree analysis, a 1.05 Mega base region in the same 8q24.23 locus was identified in a second pedigree (false-positive rate [duo]=0.0019). The intersecting region at the 8q24.23 locus contains FAM135B (family with sequence similarity 135 member B) and KHDRBS3 (KH RNA-binding domain containing, signal transduction associated 3) genes, which have previously been implicated in oncogenesis and ovarian cancer, respectively. Duo-pedigree SPTB analysis also identified a second genome-wide significant 67 kilo base locus in chromosome 12 (12q21.1-q21.2) that was shared by all women with SPTB in two independent pedigrees (false-positive rate [duo]=0.01). The intersecting region at the 12q21.1-q21.2 locus contains CAPS2 (calcyphosine 2) and KCNC2 (potassium voltage-gated channel subfamily C member 2) genes, both implicated in vascular-related complications of pregnancy and preterm labor.

CONCLUSION

Using large SPTB families, we identified shared chromosomal regions (8q24.23 and 12q21.1-q21.2), providing evidence for inherited (segregating) risk loci in SPTB etiology. Further investigation into genes in SPTB etiology, including functional validation may provide avenues for novel therapeutic development and guide efforts for SPTB prevention to prolong pregnancy and improve outcomes.

Maternal Risk Factors, Patterns, and Outcomes of Antenatal Congenital Anomalies: A Hospital-Based Study

Background/Objective: Congenital anomalies (CAs) are structural or functional abnormalities contributing to global neonatal morbidity and mortality. Data on antenatally diagnosed CAs in southern Jordan are limited. The present study reports their prevalence and patterns at the Maternal-Fetal Medicine Clinic of a governmental hospital and examines associated maternal, pregnancy, and delivery outcomes. Methods: This retrospective, hospital-based study involved all pregnant women who presented to the clinic between January 2022 to December 2023 and were diagnosed with congenital fetal anomalies. Data about maternal characteristics, classification of fetal anomalies, and pregnancy outcomes were retrieved from medical files. Statistical analyses comprised chi-square tests, Fisher's exact tests, independent t-tests, and multiple binary logistic regressions. Results: Among the 750 pregnant women, 74 (9.9%) were diagnosed with CAs. Urinary system anomalies were the most common (54.1%), followed by central nervous system (CNS) anomalies (37.8%). Major anomalies constituted 59.5%, whereas 40.5% were minor anomalies. Gestational age at diagnosis and birthweight were significantly associated with major anomalies (p < 0.05). All stillbirths (10.8%) and pregnancy losses before 24 weeks of gestation (9.5%) occurred in cases with major anomalies (p < 0.05). Though preterm delivery rates were higher with major anomalies, this association was not statistically significant. Conclusions: Major CAs (59.5%) in this southern Jordan cohort were strongly linked to stillbirths and early pregnancy loss, highlighting the need for early diagnosis and improved prenatal care. Targeted interventions, including anomaly scans and risk factor (RF) screening, may reduce the 9.9% prevalence observed.

Inflammatory Indices and Preterm Delivery: A New Horizon in Obstetric Risk Assessment

Objective: Preterm delivery is a leading cause of neonatal morbidity and mortality globally, with inflammation playing a crucial role in its pathophysiology. This study aimed to evaluate the predictive value of systemic inflammatory response indices in identifying pregnant women at risk of preterm delivery. Methods: This retrospective study analyzed data from 1128 pregnant women admitted to a tertiary care hospital between 2020 and 2025. Patients were classified into two groups: preterm delivery (n = 528) and term delivery (n = 600). Demographic characteristics, obstetric history, neonatal outcomes, and inflammatory indices were compared. Results: The preterm delivery group showed a significantly higher systemic inflammatory response index (SIRI) (p < 0.001), systemic immune-inflammation index (SII) (p < 0.001), neutrophil/lymphocyte ratio (NLR) (p < 0.001), and monocyte/lymphocyte ratio (MLR) (p < 0.001) than the term delivery group, while platelet/lymphocyte ratio (PLR) levels were significantly lower (p = 0.002). Inflammatory indices were higher in early preterm delivery cases (p < 0.001) than in middle and late preterm cases. Multivariate logistic regression identified the SIRI (p = 0.015) and NLR (p < 0.001) as independent predictors of preterm delivery, while the PLR showed an inverse association (p = 0.002). Higher inflammatory indices correlated with lower 1st and 5th minute APGAR scores (p < 0.001) and increased neonatal intensive care unit (NICU) admission rates (p < 0.001). NICU stay was prolonged in neonates born to mothers with elevated SIRI and NLR levels (p < 0.001). Conclusions: Integrating these inflammatory indices into obstetric risk assessment may enhance early detection and intervention strategies, potentially improving maternal and neonatal prognosis.

Focussing on the origins of preterm birth: Why understanding aetiology is critical to optimising outcomes

Preterm birth is a central determinant of infant morbidity and mortality. Efforts to reduce its incidence must address the disparate underlying causes.

Soluble fms-like tyrosine kinase-1/placental growth factor ratio at 36 weeks' gestation: association with spontaneous onset of labor and intrapartum fetal compromise in low-risk pregnancies

BACKGROUND

Previous evidence showed that placental dysfunction triggers spontaneous preterm or term births and intrapartum fetal compromise and often requires urgent delivery, thereby exposing both the fetus and the mother to significant risks. Predicting spontaneous labor onset and intrapartum fetal compromise could improve obstetrical management and outcomes, but this is currently difficult, particularly in low-risk populations.

OBJECTIVE

The objective of this study was to examine whether placental dysfunction, as assessed at 36 weeks' gestation by the soluble fms-like tyrosine kinase-1 to placental growth factor ratio, is associated with the interval to spontaneous onset of labor and intrapartum fetal compromise that requires cesarean delivery in a routinely examined population.

STUDY DESIGN

This was a retrospective analysis of prospectively collected data of women with singleton pregnancies who underwent routine assessment at 35+0 to 36+6 weeks' gestation at the King's College Hospital (London, England). Using a general linear model, the study examined the outcomes related to the soluble fms-like tyrosine kinase-1/placental growth factor ratio, including the time interval from testing to spontaneous onset of labor and the subsequent rate of fetal compromise that required a cesarean delivery. Patients who underwent induction of labor or prelabor cesarean deliveries were excluded from the study. Competing risks regression and Cox regression models were used to estimate the cumulative incidence and the risk of the outcomes of interest.

RESULTS

In the screened population of 45,375 patients, 23,831 (52.5%) had spontaneous onset of labor and were included in the analysis. Cases with an soluble fms-like tyrosine kinase-1/placental growth factor ratio >50 delivered about 1 week earlier than those with a ratio of ≤50 (39.2 vs 40.0 weeks' gestation; P<.001). The general linear model showed that a larger soluble fms-like tyrosine kinase-1/placental growth factor ratio was associated with earlier spontaneous onset of labor (P<.001), particularly among multiparous women. The soluble fms-like tyrosine kinase-1/placental growth factor ratio was significantly associated, as expected, with cases of preeclampsia and advanced maternal age. The cumulative incidence of spontaneous onset of labor was significantly higher in cases with an soluble fms-like tyrosine kinase-1/placental growth factor ratio >50 than in those with a ratio 50 (P<.001). Cox regression showed that the risk for spontaneous onset of labor increased with an soluble fms-like tyrosine kinase-1/placental growth factor ratio >50 (hazard ratio, 1.424; 95% confidence interval, 1.253-1.618; P<.001) and, as expected, the risk was mitigated over time from when the soluble fms-like tyrosine kinase-1/placental growth factor ratio was measured to spontaneous labor onset (P<.001). Cases with intrapartum fetal compromise had a higher mean soluble fms-like tyrosine kinase-1/placental growth factor ratio than those without intrapartum fetal compromise (21.79 vs 17.67; P<.001). Qualitative addition of fetal compromise to the general linear model showed a higher soluble fms-like tyrosine kinase-1/placental growth factor ratio in cases with fetal compromise than in those without fetal compromise (P=.014). Competing risks regression showed a positive dose-response effect for fetal compromise with increasing soluble fms-like tyrosine kinase-1/placental growth factor ratios (P<.001). Above and below the optimal cutoff of 50, the quoted cumulative incidences were 6.7% and 4.7%, respectively (P<.001). The effect of the soluble fms-like tyrosine kinase-1/placental growth factor ratio remained significant even after adjusting for preeclampsia, which is a well-known major risk factor for fetal compromise. Finally, the proportion of cases with intrapartum fetal compromise who had an soluble fms-like tyrosine kinase-1/placental growth factor ratio >50 decreased from 35% to 0% with advancing gestation.

CONCLUSION

This study showed that an increased soluble fms-like tyrosine kinase-1/placental growth factor ratio at 36 weeks' gestation is associated with an earlier gestational age at spontaneous onset of labor and higher rates of intrapartum fetal compromise. There are 2 major implications, namely an soluble fms-like tyrosine kinase-1/placental growth factor ratio >50 indicates imminent labor onset with about a 40% mean risk increase and immediate clinical translation for term pregnancy monitoring. In addition, an increased soluble fms-like tyrosine kinase-1/placental growth factor ratio increases the risk for intrapartum fetal compromise, although outcome variability indicates reassessment within multimarker models.

Predictors of preterm births in North Dakota: a retrospective study of the North Dakota Pregnancy Risk Assessment Monitoring System (PRAMS)

Background

Preterm births represent approximately 10% of all births in the United States (US) annually. Although North Dakota (ND) has large rural and American Indian populations that experience disparities in health outcomes relative to the general population, few studies have investigated risk factors of preterm births in this state. Therefore, the objective of this study was to investigate predictors of preterm births in ND among women who had a live singleton birth and no prior history of preterm births.

Methods

Data on live births from 2017 to 2021 were obtained from the ND Pregnancy Risk Assessment Monitoring System. Potential predictors of preterm birth were identified using a conceptual model. Multivariable logistic regression was then used to investigate and identify significant predictors of preterm births.

Results

The overall prevalence of preterm birth in North Dakota from 2017 to 2021 was 8.1%. However, among the population of interest in this study, which excluded births with multiple infants as well as women with a prior history of preterm birth, the preterm birth rate was 6.4%. Race, age, pregestational diabetes, and gestational hypertension were significantly associated with preterm birth in the final multivariable logistic model. The odds of preterm birth were higher among women who were American Indian (adjusted odds ratio (AOR) = 1.7, 95% confidence interval (CI) [1.3-2.4]), were aged 35 years or older (AOR = 1.6, 95% CI [1.01-2.5]), had pregestational diabetes (AOR = 4.3, 95% CI [2.0-9.3]), and had gestational hypertension (AOR = 4.5, 95% CI [3.1-6.7]) compared to women who were White, aged 20-34 years, and did not have pregestational diabetes or gestational hypertension.

Conclusions

Preventing and controlling chronic diabetes and hypertensive disorders of pregnancy is critical for reducing the risk of preterm birth, especially among women of advanced maternal age. Further research is needed to understand the underlying causes of racial disparities of preterm birth in ND.

Global and population-specific association of MTHFR polymorphisms with preterm birth risk: a consolidated analysis of 44 studies

BACKGROUND

This study investigates the relationship between polymorphisms in the MTHFR gene and the risk of preterm birth (PTB).

METHODS

A comprehensive literature review was conducted using databases such as PubMed, Web of Science, and CNKI, with the search finalized on January 1, 2025. The review specifically targeted studies published prior to this date, utilizing relevant keywords and MeSH terms associated with PTB and genetic factors. Inclusion criteria encompassed original case-control, longitudinal, or cohort studies, with no limitations on language or publication date. Associations were quantified using odds ratios (ORs) and 95% confidence intervals (CIs) via Comprehensive Meta-Analysis software.

RESULTS

The analysis included 44 case-control studies comprising 7,384 cases and 51,449 controls, extracted from 28 publications in both English and Chinese. Among these studies, 29 focused on the MTHFR C677T polymorphism, while 15 examined the MTHFR A1298C variant. Pooled results demonstrated a significant association between the MTHFR C677T polymorphism and PTB under five genetic models: allele (C vs. T; OR = 1.303, 95% CI 1.151-1.475, p ≤ 0.001), homozygote (CC vs. AA; OR = 1.494, 95% CI 1.212-1.842, p ≤ 0.001), heterozygote (CT vs. AA; OR = 1.303, 95% CI 1.119-1.516, p = 0.001), dominant (CC + CT vs. AA; OR = 1.341, 95% CI 1.161-1.548, p ≤ 0.001), and recessive (CC vs. CT + AA; OR = 1.340, 95% CI 1.119-1.604, p = 0.001). Subgroup analyses indicated significant associations in Asian populations, particularly in studies conducted in China and India, while no significant correlations were found in Caucasian populations, including those from Austria. Moreover, the MTHFR A1298C polymorphism did not demonstrate a significant relationship with PTB risk across the studied ethnicities.

CONCLUSIONS

The findings indicate a significant association between the MTHFR C677T polymorphism and PTB risk, particularly in Asian and Indian populations, while no significant associations were identified in Caucasian groups. Conversely, the MTHFR A1298C polymorphism appeared to have a negligible impact on PTB risk, underscoring the importance of considering population-specific factors in understanding the genetic epidemiology of PTB.

The association between interpregnancy intervals and preterm birth: a systematic review and meta-analysis

BACKGROUND

Research has shown a relationship between interpregnancy intervals (IPIs) and preterm birth, but a comprehensive understanding remains elusive. The aim of this systematic review and meta-analysis was to examine the effect of different IPIs on the risk of preterm birth METHODS: Systematic searches were conducted in PubMed, Cochrane, Web of Science, and Embase up to June 2, 2023. Studies included in the review provided data on IPIs and preterm birth outcomes, assessed via the NOS quality scale. A Bayesian network meta-analysis was performed to evaluate the association between IPIs and preterm birth.

RESULTS

From 34 studies and 8,646,679 individuals, the optimal IPIs were found to be 24-29 months, showing significantly lower risks of preterm birth at less than 32 weeks of gestation [OR=0.55 (95%CI: 0.50 - 0.62)]and at less than 37 weeks of gestation[OR=0.61 (95%CI: 0.59 - 0.63)]compared to IPIs less than 5 months.

CONCLUSIONS

IPIs of 24-29 months significantly reduce the risk of preterm birth, suggesting a potential target range for family planning and clinical recommendations.

TRIAL REGISTRATION

Not applicable.

Seasonal Influences on Human Placental Transcriptomes Associated with Spontaneous Preterm Birth

Demographic studies have revealed a strong association between exposure to high ambient temperatures during pregnancy and increased risks of preterm birth (PTB). The mechanism underlying this association is unclear, but it is plausible that altered placental function may contribute to it. In this study, we conducted differential gene expression analysis, gene set enrichment analysis (GSEA), and gene ontology (GO) analysis on bulk RNA-seq data from human placentas delivered at term and preterm during the warmer months compared to placentas delivered at term and preterm during the colder months in the UK. We detected 48 differentially expressed genes in preterm placentas delivered during the warmer months compared to preterm placentas delivered during the colder months, the majority of which were inflammatory cytokines and chemokines, including SERPINA1, IL1B, CCL3, CCL3L3, CCL4, CCL4L2, CCL20, and CXCL8. The GSEA positively enriched 17 signalling pathways, including the NF-κB, IL17, Toll-like receptor, and chemokine signalling pathways in preterm placentas delivered during warmer months. These results were not observed in the placentas delivered at term during the same times of the year. The GO analysis revealed several enhanced biological processes, including neutrophil, granulocyte, monocyte, and lymphocyte chemotaxis, as well as inflammatory and humoral immune responses in preterm placentas, but not in placentas delivered at term in the summer. We conclude that maternal exposure to warm environmental temperatures during pregnancy likely alters the placental transcriptomes towards inflammation and immune regulation, potentially leading to PTB.

Atypical mediastinal mass in the fetus: a review of the literature

OBJECTIVES

Congenital thoracic masses (CTMs) are suspected in presence of solid or cystic thoracic lesions at ultrasound. The common typical fetal CTMs encompass: hyperechogenic lung lesions such as congenital pulmonary airway malformation (CPAM), broncopulmonary sequestration (PS) and congenital high airway obstruction syndrome (CHAOS); less common solid thoracic masses are mediastinal/pericardial tumors as rhabdomyoma and teratoma. The aim of our study is to gather the available evidence on cases of atypical CTMs of difficult classification, for which the diagnosis remains often uncertain.

METHODS

A review of the literature on the prenatal diagnosis of CTMs was performed, focusing on ultrasound features, postnatal manifestation, treatment and neonatal outcome. Inclusion criterion was prenatal diagnosis of CTM cases with difficult classification in six typical categories. A summary of results was carried out.

RESULTS

The literature review included six studies in the analysis. Two cases experienced intrauterine fetal death, one with hydrops in rhabdomyoma and another one for a rapid growth of the mass, with autopsies precising the diagnoses. In two other instances, surgery after birth provided also different histologic diagnoses. All surviving children were asymptomatic at follow-up. One case with rhabdomyoma and another one with atypical pericardial teratoma showed spontaneous regression. Moreover we are presenting our unpublished case of an atypical mass diagnosed as rhabdomyoma or broncopulmonary sequestration.

CONCLUSIONS

Some masses may present atypical presentation of a known disease or we may face rare diagnosis for which there is lack of information in the literature. The definitive diagnosis still relies on histologic analysis.

Predicting Adverse Neurodevelopmental Outcomes in Premature Neonates with Intrauterine Growth Restriction Using a Three-Layered Neural Network

Background/Objectives: There is a constant need to improve the prediction of adverse neurodevelopmental outcomes in growth-restricted neonates who were born prematurely. The aim of this retrospective study was to evaluate the predictive performance of a three-layered neural network for the prediction of adverse neurodevelopmental outcomes determined at two years of age by the Bayley Scales of Infant and Toddler Development, 3rd edition (Bayley-III) scale in prematurely born infants by affected by intrauterine growth restriction (IUGR). Methods: This observational retrospective study included premature newborns with or without IUGR admitted to a tertiary neonatal intensive care unit from Romania, between January 2018 and December 2022. The patients underwent assessment with the Amiel-Tison scale at discharge, and with the Bailey-3 scale at 3, 6, 12, 18, and 24 months of corrected age. Clinical and paraclinical data were used to construct a three-layered artificial neural network, and its predictive performance was assessed. Results: Our results indicated that this type of neural network exhibited moderate predictive performance in predicting mild forms of cognitive, motor, and language delays. However, the accuracy of predicting moderate and severe neurodevelopmental outcomes varied between moderate and low. Conclusions: Artificial neural networks can be useful tools for the prediction of several neurodevelopmental outcomes, and their predictive performance can be improved by including a large number of clinical and paraclinical parameters.

Maternal social deprivation and preterm birth: The PreCARE cohort study

BACKGROUND

Maternal exposure to unfavourable social conditions is associated with a higher rate of perinatal complications, such as placental vascular pathologies. A higher risk of preterm birth (PTB) has also been reported, and variations across studies and settings suggest that different patterns may be involved in this association.

OBJECTIVE

To assess the association between maternal social deprivation and PTB (overall and by phenotype).

METHODS

We analysed 9365 patients included in the PreCARE cohort study. Four dimensions (social isolation, insecure housing, no income from work and absence of standard health insurance) defined maternal social deprivation (exposure). They were considered separately and combined into a social deprivation index (SDI). The associations between social deprivation and PTB <37 weeks (primary outcome) were analysed with univariable and multivariable log-binomial models (adjusted for maternal age, parity, education level and birthplace). Then we used multinomial analysis to examine the association with preterm birth phenotypes (secondary outcome): spontaneous labour, preterm prelabour rupture of membranes (PPROM) and placental vascular pathologies.

RESULTS

In all, 66.3%, 17.8%, 8.9% and 7.0% of patients had an SDI of 0, 1, 2 and 3, respectively. Social isolation affected 4.5% of the patients, insecure housing 15.5%, no income from work 15.6% and no standard health insurance 22.4%. Preterm birth complicated 7.0% of pregnancies (39.8% spontaneous labour, 28.3% PPROM, 21.8% placental vascular pathologies and 10.1% other phenotypes). Neither the univariable nor multivariable analyses found any association between social deprivation and the risk of preterm birth overall (SDI 1 versus 0: aRR 1.02, 95% confidence interval [CI] 0.83, 1.26; 2 versus 0: aRR 1.05, 95% CI 0.80, 1.38; 3 versus 0: aRR 0.92, 95% CI 0.66, 1.29) or its different phenotypes.

CONCLUSIONS

In the French PreCARE cohort, we observed no association between markers of social deprivation and the risk of preterm birth, regardless of phenotype.

The Emerging Role of Sonoelastography in Pregnancy: Applications in Assessing Maternal and Fetal Health

Sonoelastography, a novel ultrasound-based technique, is emerging as a valuable tool in prenatal diagnostics by quantifying tissue elasticity and stiffness in vivo. This narrative review explores the application of sonoelastography in assessing maternal and fetal health, with a focus on cervical, placental, pelvic floor, and fetal tissue evaluations. In the cervix, sonoelastography aids in predicting preterm birth and assessing labor induction success. For the placenta, it provides insights into conditions like preeclampsia and intrauterine growth restriction through elasticity measurements. Assessing fetal tissues, including the lungs, liver, and brain, sonoelastography offers a non-invasive method for evaluating organ maturity and detecting developmental anomalies. Additionally, pelvic floor assessments enable better management of childbirth-related injuries and postpartum recovery. While current studies support its safety when used within established limits, further research is necessary to confirm long-term effects. Future advancements include refining protocols, integrating machine learning, and combining sonoelastography with other diagnostic methods to enhance its predictive power. Sonoelastography holds promise as an impactful adjunct to conventional ultrasound, providing quantitative insights that can improve maternal and fetal outcomes in prenatal care.

Causal Relationships Between Leukocyte Subsets and Adverse Fetal Outcomes: A Mendelian Randomization Study

Background: The tolerance and dynamic regulation of the maternal immune system during pregnancy are pivotal for ensuring fetal health. Immune cell subsets play a complex and crucial role in this process, closely linked to the neonatal health status. Despite recognizing the significance of dysregulation in the quantity and activity of immune cells in neonatal disease occurrence, their specific roles remain elusive, resulting in a dearth of clinically viable interventions for immune-mediated neonatal diseases. Materials and Methods: Employing two-sample Mendelian randomization (MR) methodology, this study systematically investigated 446 leukocyte features (N = 500,675), including leukocyte subsets, absolute cell (AC) counts, and morphological parameters (MP) and their correlation with seven adverse fetal outcomes (N = 1,100,458), encompassing fetal growth restriction (FGR), preterm birth (PTB), neonatal jaundice (NNJ), digestive system disorders of fetus and newborn (DSDFN), hemorrhagic and hematological disorders of fetus and newborn (HDFN), respiratory distress of newborn (RDN), and transitory disorders of metabolism specific to fetus and newborn (TDMSFN). Results: The results unveiled significant causal relationships between 301 leukocyte subsets and these seven adverse fetal outcomes, with 259, 245, 15, 44, 11, 32, and 68 pairs of notable associations for each adverse outcome, respectively. Furthermore, the study highlighted potential pathogenic mechanisms underlying the mutual influence among neonatal diseases. MR results indicated FGR as a robustly correlated risk factor for PTB and NNJ and showed a reciprocal causal relationship between NNJ and FGR. PTB exhibited a positive correlation with HDFN. Conclusions: This study provided profound insights into the intricate regulatory mechanisms of leukocyte subsets in neonatal diseases, paving the way for new avenues in the diagnosis and treatment of associated disorders.

A simplified pre-conceptional laparoscopic cervical cerclage for cervical insufficiency: a retrospective study from a single center

BACKGROUND

Cervical insufficiency is a pathological condition in obstetrics in which the cervix fails to retain the fetus before uterine contractions or labor (painless cervical dilatation). Patients usually have fetal loss in the mid-trimester or spontaneous pre-term birth due to painless cervical dilation. For non-pregnant women with cervical insufficiency, prophylactic laparoscopic abdominal cerclage (LAC) has been reported to improve pregnancy outcomes, such as live birth, neonatal survival, and full-term delivery rate. Conventional LAC involves opening the vesicular space and separating the anterior broad ligament leaves. In our surgical procedure, these two steps were omitted.

METHODS

An observational study was conducted retrospectively on patients who underwent a simplified pre-conceptional LAC between January 2015 and December 2022 at West China Second University Hospital, Sichuan University. Follow-ups for all the patients ended at the delivery of the fetus. Subsequently, clinical characteristics, perioperative data, and obstetric outcomes were recorded and analyzed.

RESULTS

In total, 108 patients were included in a pre-conception LAC group Mean operation time was 56.8 ± 22.8 min, and mean estimated blood loss was 21.4 ± 23.6 mL. Only one case of urinary retention was classified as a grade I postoperative complication, according to the Clavien-Dindo classification. No severe complications or sequelae were observed during the perioperative period. Obstetric outcomes from 98 patients were collected: three patients had miscarriages, and 95 had live births. Of the 95 live births, 4 were twins and 91 were singletons. Two patients had vaginal delivery, and 93 underwent Cesarean section; mean neonatal weight was 3310.2 ± 382.1 g.

CONCLUSION

A simplified pre-conceptional LAC is a simple, safe, and effective method for women with cervical insufficiency. Thus, it is worthy of promotion to assist women with cervical insufficiency in achieving improved obstetric outcomes. Vaginal delivery after LAC is possible once the tape is removed before labor.

Prediction of risk for early or very early preterm births using high-resolution urinary metabolomic profiling

BACKGROUND

Preterm birth (PTB) is a serious health problem. PTB complications is the main cause of death in infants under five years of age worldwide. The ability to accurately predict risk for PTB during early pregnancy would allow early monitoring and interventions to provide personalized care, and hence improve outcomes for the mother and infant.

OBJECTIVE

This study aims to predict the risks of early preterm (< 35 weeks of gestation) or very early preterm (≤ 26 weeks of gestation) deliveries by using high-resolution maternal urinary metabolomic profiling in early pregnancy.

DESIGN

A retrospective cohort study was conducted by two independent preterm and term cohorts using high-density weekly urine sampling. Maternal urine was collected serially at gestational weeks 8 to 24. Global metabolomics approaches were used to profile urine samples with high-resolution mass spectrometry. The significant features associated with preterm outcomes were selected by Gini Importance. Metabolite biomarker identification was performed by liquid chromatography tandem mass spectrometry (LCMS-MS). XGBoost models were developed to predict early or very early preterm delivery risk.

SETTING AND PARTICIPANTS

The urine samples included 329 samples from 30 subjects at Stanford University, CA for model development, and 156 samples from 24 subjects at the University of Alabama, Birmingham, AL for validation.

RESULTS

12 metabolites associated with PTB were selected and identified for modelling among 7,913 metabolic features in serial-collected urine samples of pregnant women. The model to predict early PTB was developed using a set of 12 metabolites that resulted in the area under the receiver operating characteristic (AUROCs) of 0.995 (95% CI: [0.992, 0.995]) and 0.964 (95% CI: [0.937, 0.964]), and sensitivities of 100% and 97.4% during development and validation testing, respectively. Using the same metabolites, the very early PTB prediction model achieved AUROCs of 0.950 (95% CI: [0.878, 0.950]) and 0.830 (95% CI: [0.687, 0.826]), and sensitivities of 95.0% and 60.0% during development and validation, respectively.

CONCLUSION

Models for predicting risk of early or very early preterm deliveries were developed and tested using metabolic profiling during the 1st and 2nd trimesters of pregnancy. With patient validation studies, risk prediction models may be used to identify at-risk pregnancies prompting alterations in clinical care, and to gain biological insights of preterm birth.

Impact of suspected preterm labour in foetal cardiovascular and metabolic programming: a prospective cohort study protocol

INTRODUCTION

Suspected preterm labour (SPL) is an obstetric complication that occurs in 9% of all pregnancies and is the leading cause of antenatal hospital admissions. More than half of women with SPL deliver a premature baby which is a known risk factor for developing cardiovascular and metabolic disorders in childhood and later in adult life. On the other hand, the other half of these women will deliver at term, labelled as 'false preterm labour'. Although this has been thought to be a benign condition, accumulating evidence reported in recent years showed long-term effects for the foetus, neonate and infant even when birth occurs at term. However, the impact of SPL on cardiovascular and metabolic programming has not been studied yet. The aim of this prospective cohort study is to evaluate the impact of SPL on cardiac remodelling and function and on cardiovascular and metabolic profiles independently of gestational age at birth.

METHODS AND ANALYSIS

Prospective cohort study of subjects exposed and not exposed to an episode of SPL. Women with singleton pregnancies who are admitted at a tertiary hospital due to SPL and matched controls will be recruited. Evaluation of cardiovascular remodelling by foetal echocardiography will be performed during admission. Cord blood will be collected at birth in order to analyse different metabolomic footprints and several cardiovascular and metabolic risk biomarkers. Moreover, children will undergo an echocardiography 6 months after birth. The relationship between SPL and cardiovascular and metabolic programming will be modelled considering different covariates such as socioeconomic factors, perinatal characteristics, lifestyle, diet and exercise.

ETHICS AND DISSEMINATION

Ethical approval was granted in April 2020 from CEIC Aragón (CEICA) (C.P.-C.I. PI20/136). Study outcomes will be disseminated at international conferences and published in peer-reviewed scientific journals.

TRIAL REGISTRATION NUMBER

NCT05670665.

Development and validation of a spontaneous preterm birth risk prediction algorithm based on maternal bioinformatics: A single-center retrospective study

BACKGROUND

Spontaneous preterm birth (sPTB) is a primary cause of adverse neonatal outcomes. The objective of this study is to analyze the factors influencing the occurrence of sPTB in pregnant women and to construct and validate a predictive model for sPTB risk based on big data from clinical and laboratory assessments during pregnancy.

METHODS

A retrospective analysis was conducted on the clinical data of 3,082 pregnant women, categorizing those who delivered before 37 weeks of gestation as the sPTB group and those who delivered at or after 37 weeks as the full-term group. The performance of five machine learning models was compared using metrics such as the AUC, accuracy, sensitivity, specificity, and precision to identify the optimal predictive model. The top 10 predictive variables were selected based on their significance in disease prediction. The data were then divided into a training set (70%) and a validation set (30%) for validation. External data were also utilized to validate the model's predictive performance.

RESULTS

A total of 24 indicators with significant differences were identified. In terms of predicting the risk of preterm birth, the XGBoost algorithm demonstrated the most outstanding performance, with an AUCROC of 0.89 (95% CI: 0.88-0.90). The top 10 critical indicators included ALP, AFP, ALB, HCT, TC, DBP, ALT, PLT, height, and SBP, which are essential for constructing an accurate predictive model. The model exhibited stable performance on both the training and validation sets, with AUC values of 0.93 and 0.87, respectively. Furthermore, the external testing set also showed superior performance, with an AUC of 0.79.

CONCLUSIONS

At the time of delivery, ALP, AFP, ALB, HCT, TC, DBP, ALT, PLT, height, and SBP are influential factors for sPTB in pregnant women. The XGBoost algorithm, constructed based on these factors, demonstrated the most outstanding performance.

Revisiting Utility of Fetal Autopsy in Genomic Era

Background: Autopsy has been a gold standard in cases of antenatal detected anomalies or fetal demise. This helped clinicians in getting insights into the future management. In current times, ultrasound and genomic testing has become extremely powerful in further refining the etiological basis; however, fetal autopsy still has its role even now. Material and Methods: We have discussed the utility of fetal autopsy in current times by diving the cases in seven groups. Results: Case based discussions to discuss the utility of fetal autopsy. Conclusions: We suggest that fetal autopsy should be the standard of care in case of any abnormal fetal outcomes alongwith fetal genomic testing. Fetal autopsy is complementary to the ultrasound assessment and genomic investigations in reaching the final diagnosis and provides invaluable information regarding recurrence risk which may not be available when couple plans next pregnancy.

Preterm birth in singleton pregnancies conceived by in vitro fertilization or intracytoplasmic sperm injection: an overview of systematic reviews

BACKGROUND

The rate of preterm birth of singletons conceived through in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI) is increased, being as high as 15% to 16% across Europe and the United States. However, the underlying etiology, phenotype, and mechanisms initiating preterm birth (PTB) are poorly understood.

OBJECTIVE

To quantify the PTB risk and examine supposed etiology in IVF/ICSI singleton pregnancies compared to naturally conceived.

STUDY DESIGN

Overview of reviews including all available systematic reviews with meta-analysis comparing PTB risk in IVF/ICSI and naturally conceived singletons. A comprehensive search of PubMed/MEDLINE, Embase, Scopus, and Cochrane Library databases was performed up to December 31, 2023. Information available on etiology, phenotype, initiation of PTB, and relevant moderators was retrieved and employed for subgroup analyses. Random-effects meta-analysis models were used for pooling effect measures. Estimates were presented as odds ratios (ORs) with 95% confidence intervals (CIs). The extent of overlap in the original studies was measured using the corrected covered area assessment. The quality of the included reviews was evaluated with the AMSTAR 2 tool. The Grading of Recommendations Assessment, Development and Evaluation approach was applied to rate evidence certainty. The protocol was registered on PROspective Register of Systematic Reviews (CRD42023411418).

RESULTS

Twelve meta-analyses (16,522,917 pregnancies; ˃433,330 IVF/ICSI) were included. IVF/ICSI singletons showed a significantly higher PTB risk compared to natural conception (PTB ˂37 weeks: OR: 1.72, 95% CI: 1.57-1.89; PTB<32 weeks: OR: 2.19, 95% CI: 1.82-2.64). Influential analysis reinforced the strength of this association. Subgroup analyses investigating supposed etiology revealed a comparable risk magnitude for spontaneous PTB (OR: 1.79, 95% CI: 1.56-2.04) and a greater risk for iatrogenic PTB (OR: 2.28, 95% CI: 1.72-3.02). PTB risk was consistent in the subgroup of conventional IVF (OR: 1.95, 95% CI: 1.76-2.15) and higher in the subgroup of fresh only (OR: 1.79, 95% CI: 1.55-2.07) vs frozen-thawed embryo transfers (OR: 1.39, 95% CI: 1.34-1.43). There was minimal study overlap (13%). The certainty of the evidence was graded as low to very low.

CONCLUSION

Singletons conceived through IVF/ICSI have a 2-fold increased risk of PTB compared to natural conception, despite the low certainty of the evidence. There is paucity of available data on PTB etiology, phenotype, or initiation. The greater risk increase is observed in fresh embryo transfers and involves iatrogenic PTB and PTB ˂32 weeks, likely attributable to placental etiology. Future studies should collect data on PTB etiology, phenotype, and initiation. IVF/ICSI pregnancies should undertake specialistic care with early screening for placental disorders, cervical length, and growth abnormalities, allowing appropriate timely follow-up, preventive measures, and therapeutic interventions strategies.

Clinical Characteristics and Current Treatment Modality of Preterm Infants with Ureaplasma spp. Infection

BACKGROUND

The impact of and countermeasures for Ureaplasma spp. in neonates remain controversial. The aim of this study was to evaluate the associated perinatal factors that can predict the likelihood of respiratory tract Ureaplasma spp. colonization and analyze the subsequent clinical course of affected infants, thereby providing the rationale for their diagnosis, treatment, and future study.

METHODS

This was a retrospective observational study of infants born at a gestational age (GA) of less than 32 weeks.

RESULTS

The prevalence of respiratory tract Ureaplasma spp. colonization was 25.8% (75/291), and it increased with a decrease in GA and birth weight (BW). Maternal vaginal Ureaplasma spp. colonization increased the risk of neonatal Ureaplasma spp. colonization, with an OR of 7.8 (95% CI: 3.1, 20.0). Infants with Ureaplasma spp. colonization had a higher white blood cell (WBC) count, normal C-reactive protein (CRP) level, and higher failure rate of weaning from mechanical ventilation (30.7% vs. 17.1%, p = 0.014); they also suffered more from interstitial pneumonia (20.0% vs. 5.6%, p < 0.001) and bronchopulmonary dysplasia (36.0% vs. 13.4%, p < 0.001). Infants receiving anti-Ureaplasma spp. treatment had a lower GA, lower BW, and more severe respiratory syndromes. However, the difference in respiratory manifestation became insignificant after adjusting for GA.

CONCLUSIONS

GA and maternal vaginal Ureaplasma spp. colonization could be used to predict neonatal respiratory tract Ureaplasma spp. colonization. An elevated WBC count combined with normal CRP is a good marker of Ureaplasma spp. colonization/infection. It is conventional practice to start anti-Ureaplasma spp. treatment when infants present with a deteriorated respiratory condition. This practice warrants further investigation considering GA as a predominant intermediate variable.

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

PURPOSE

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.

METHODS

A prospective study on 1107 singleton pregnant women between 16+0 and 23+6 weeks 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 37 weeks 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.

RESULTS

A uterocervical angle ≥ 99° predicted spontaneous preterm birth at < 37 weeks, with a sensitivity and specificity of 91% and 76%, respectively. A cervical length ≤ 33.8 mm predicted preterm birth at < 37 weeks with a sensitivity and specificity of 25% and 66%, respectively. A uterocervical angle ≥ 99° combined with a cervical length ≤ 33.8 mm 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.

CONCLUSION

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.

Zuranolone therapy protects frontal cortex neurodevelopment and improves behavioral outcomes after preterm birth

BACKGROUND

Preterm birth is associated with brain injury and long-term behavioral abnormalities, for which there are limited prevention options. When born preterm, infants prematurely lose placental neurosteroid (allopregnanolone) support. This increases the risk of excitotoxic damage to the brain, which increases the risk of injury, causing long-term deficits in behavior, myelination, and alterations to neurotransmitter pathways. We propose that postnatal restoration of neurosteroid action through zuranolone therapy will reduce neurological impairments following preterm birth.

METHODS

Guinea pig dams underwent survival cesarean section surgery to deliver pups prematurely (GA64) or at term (GA69). Between birth and term equivalence age, preterm pups received vehicle (15% β-cyclodextrin) or the allopregnanolone analogue zuranolone (1 mg/kg/day). Behavioral analysis was performed at postnatal day (PND) 7 and 40, before tissue collection at PND 42. Immunostaining for myelin basic protein (MBP), as well as real-time polymerase chain reaction to characterize oligodendrocyte lineage and neurotransmitter pathways, was performed in frontal cortex tissues.

RESULTS

Zuranolone treatment prevented the hyperactive phenotype in preterm-born offspring, most markedly in males. Additionally, preterm-related reductions in MBP were ameliorated. Several preterm-related alterations in mRNA expression of dopaminergic, glutamatergic, and GABAergic pathways were also restored back to that of a term control level.

CONCLUSION

This is the first study to assess zuranolone treatment as a neuroprotective therapy following preterm birth. Zuranolone treatment improved behavioral outcomes and structural changes in the preterm offspring, which continued long term until at least a late childhood timepoint. Clinical studies are warranted for further exploring the neuroprotective possibilities of this treatment following preterm birth.

Neonatal Outcomes after Maternal Biomarker-Guided Preterm Birth Intervention: The AVERT PRETERM Trial

The AVERT PRETERM trial (NCT03151330) evaluated whether screening clinically low-risk pregnancies with a validated maternal blood biomarker test for spontaneous preterm birth (sPTB) risk, followed by preventive treatments for those screening positive, would improve neonatal outcomes compared to a clinically low-risk historical population that had received the usual care. Prospective arm participants with singleton non-anomalous pregnancies and no PTB history were tested for sPTB risk at 191/7-206/7 weeks' gestation and followed up with after neonatal discharge. Screen-positive individuals (≥16% sPTB risk) were offered vaginal progesterone (200 mg) and aspirin (81 mg) daily, with twice-weekly nurse phone calls. Co-primary outcomes were neonatal morbidity and mortality, measured using a validated composite index (NMI), and neonatal hospital length of stay (NNLOS). Endpoints were assessed using survival analysis and logistic regression in a modified intent-to-treat population comprising screen-negative individuals and screen-positive individuals accepting treatment. Of 1460 eligible participants, 34.7% screened positive; of these, 56.4% accepted interventions and 43.6% declined. Compared to historical controls, prospective arm neonates comprising mothers accepting treatment had lower NMI scores (odds ratio 0.81, 95% CI, 0.67-0.98, p = 0.03) and an 18% reduction in severe morbidity. NNLOS was shorter (hazard ratio 0.73, 95% CI, 0.58-0.92, p = 0.01), with a 21% mean stay decrease among neonates having the longest stays. Sensitivity analyses in the entire intent-to-treat population supported these findings. These results suggest that biomarker sPTB risk stratification and preventive interventions can ameliorate PTB complications in singleton, often nulliparous, pregnancies historically deemed low risk.