The association between parity and spontaneous preterm birth: a population based study

Dietary amino acids, macronutrients, vaginal birth, and breastfeeding are associated with the vaginal microbiome in early pregnancy

The vaginal microbiome is a key player in the etiology of spontaneous preterm birth. This study aimed to illustrate maternal environmental factors associated with vaginal microbiota composition and function in pregnancy. Women in healthy pregnancy had vaginal microbial sampling from the posterior vaginal fornix performed at 16 weeks gestation. After shotgun metagenomic sequencing, heatmaps of relative abundance data were generated. Community state type (CST) was assigned, and alpha diversity was calculated. Demography, obstetric history, well-being, exercise, and diet using food frequency questionnaires were collected and compared against microbial parameters. A total of 119 pregnant participants had vaginal metagenomic sequencing performed. Factors with strongest association with beta diversity were dietary lysine (adj-R2 0.113, P = 0.002), valine (adj-R2 0.096, P = 0.004), leucine (adj-R2 0.086, P = 0.003), and phenylalanine (adj-R2 0.085, P = 0.005, Fig. 2D). Previous vaginal delivery and breastfeeding were associated with vaginal beta diversity (adj-R2 0.048, P = 0.003; adj-R2 0.045, P = 0.004), accounting for 8.5% of taxonomy variation on redundancy analysis. Dietary fat, starch, and maltose were positively correlated with alpha diversity (fat +0.002 SD/g, P = 0.025; starch +0.002 SD/g, P = 0.043; maltose +0.440 SD/g, P = 0.013), particularly in secretor-positive women. Functional signature was associated with CST, maternal smoking, and dietary phenylalanine, accounting for 8.9%-11% of the variation in vaginal microbiome functional signature. Dietary amino acids, previous vaginal delivery, and breastfeeding history were associated with vaginal beta diversity. Functional signature of the vaginal microbiome differed with community state type, smoking, dietary phenylalanine, and vitamin K. Increased alpha diversity correlated with dietary fat and starch. These data provide a novel snapshot into the associations between maternal environment, nutrition, and the vaginal microbiome.

IMPORTANCE

This secondary analysis of the MicrobeMom randomized controlled trial reveals that dietary amino acids, macronutrients, previous vaginal birth, and breastfeeding have the strongest associations with vaginal taxonomy in early pregnancy. Function of the vaginal niche is associated mainly by species composition, but smoking, vitamin K, and phenylalanine also play a role. These associations provide an intriguing and novel insight into the association between host factors and diet on the vaginal microbiome in pregnancy and highlight the need for further investigation into the complex interactions between the diet, human gut, and vaginal microbiome.

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

BACKGROUND

A 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.

METHODS

A 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.

RESULTS

Between 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.

CONCLUSIONS

A 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.

County-level Structural Vulnerabilities in Maternal Health and Geographic Variation in Infant Mortality

OBJECTIVE

To evaluate whether community factors that differentially affect the health of pregnant people contribute to geographic differences in infant mortality across the United States.

STUDY DESIGN

This retrospective cohort study sought to characterize the association of a novel composite measure of county-level maternal structural vulnerabilities, the Maternal Vulnerability Index (MVI), with risk of infant death. We evaluated 11,456,232 singleton infants born at 22 0/7 through 44 6/7 weeks' gestation from 2012 to 2014. Using county-level MVI, which ranges from 0-100, multivariable mixed effects logistic regression models quantified associations per 20-point increment in MVI, with odds of death clustered at the county level and adjusted for state, maternal, and infant covariates. Secondary analyses stratified by the social, physical, and health exposures that comprise the overall MVI score. Outcome was also stratified by cause of death.

RESULTS

Odds of death were higher among infants from counties with the greatest maternal vulnerability (0.62% in highest quintile vs 0.32% in lowest quintile, [p<0.001]). Odds of death increased 6% per 20-point increment in MVI (aOR: 1.06, 95% CI 1.04, 1.07). The effect estimate was highest with theme of mental health and substance use (aOR 1.08; 95% CI 1.06, 1.09). Increasing vulnerability was associated with six of seven causes of death.

CONCLUSIONS

Community-level social, physical, and healthcare determinants indicative of maternal vulnerability may explain some of the geographic variation in infant death, regardless of cause of death. Interventions targeted to county-specific maternal vulnerabilities may reduce infant mortality.

Examining modification of the associations between air pollution and birth outcomes by neighborhood deprivation in a North Carolina birth cohort, 2011-2015

Background

Evidence from studies of air pollutants and birth outcomes suggests an association, but uncertainties around geographical variability and modifying factors still remain. As neighborhood-level social characteristics are associated with birth outcomes, we assess whether neighborhood deprivation level is an effect measure modifier on the association between air pollution and birth outcomes in a North Carolina birth cohort.

Methods

Using birth certificate data, all North Carolina residential singleton live births from 1 January 2011 to 31 December 2015 with gestational ages of 20-44 weeks (n = 566,799) were examined for birth defect diagnoses and preterm birth. Exposures were daily average fine particulate matter (PM2.5), daily 8-h maximum nitrogen dioxide (NO2), and daily 8-h maximum ozone (O3) modeled concentrations, and the modifier of interest was the neighborhood deprivation index (NDI). Linear binomial models were used to estimate the prevalence differences and 95% confidence intervals (CI) for the association between ambient air pollution and birth defect diagnoses. Modified Poisson regression models were used to estimate risk differences (RDs) and 95% CIs for air pollution and preterm birth. Models were stratified by the neighborhood deprivation index group (low, medium, or high) to assess potential modification by NDI.

Results

Approximately 3.1% of the study population had at least one birth defect and 8.18% were born preterm. For preterm birth, associations with PM2.5 and O3 did not follow a conclusive pattern and there was no evidence of modification by NDI. The associations between NO2 and preterm birth were generally negative across exposure windows except for a positive association with NO2 and preterm birth for high NDI [RD: 34.70 (95% CI 4.84-64.56)] for entire pregnancy exposure. There was no evidence of associations between pollutants examined and birth defects.

Conclusions

There may be differences in the association between NO2 exposure and preterm birth by NDI but we did not observe any evidence of associations for birth defects. Our results support the public health protection afforded by reductions in air pollution, even in areas of neighborhood deprivation, but future research conducted in areas with higher levels of air pollution and evaluating the potential for modification by neighborhood deprivation level would be informative.

Amniotic Fluid Proteomics Analysis and In Vitro Validation to Identify Potential Biomarkers of Preterm Birth

This study aimed to investigate the regulation of amniotic fibroblast (AFC) function by vitamin K-dependent protein Z (PROZ) during preterm birth (PTB) and its potential role in adverse pregnancy outcomes. Proteomic samples were collected from amniotic fluid in the second trimester, and AFC were isolated from the amniotic membrane and cultured in vitro. The expression of extracellular and intracellular PROZ in AFC was modulated, and their biological properties and functions were evaluated. Clinical analysis revealed a significant upregulation of PROZ expression in amniotic fluid from preterm pregnant women. In vitro experiments demonstrated that PROZ stimulated AFC migration, enhanced their proliferative capacity, and reduced collagen secretion. Overexpression of PROZ further enhanced cell migration and proliferation, while knockdown of PROZ had the opposite effect. PROZ plays a crucial role in promoting the proliferation and migration of amniotic membrane fibroblasts. Increased PROZ expression in amniotic fluid is associated with the occurrence of PTB. These findings shed light on the potential involvement of PROZ in adverse pregnancy outcomes and provide a basis for further research on its regulatory mechanisms during PTB.

Black-white differences in chronic stress exposures to predict preterm birth: interpretable, race/ethnicity-specific machine learning model

BACKGROUND

Differential exposure to chronic stressors by race/ethnicity may help explain Black-White inequalities in rates of preterm birth. However, researchers have not investigated the cumulative, interactive, and population-specific nature of chronic stressor exposures and their possible nonlinear associations with preterm birth. Models capable of computing such high-dimensional associations that could differ by race/ethnicity are needed. We developed machine learning models of chronic stressors to both predict preterm birth more accurately and identify chronic stressors and other risk factors driving preterm birth risk among non-Hispanic Black and non-Hispanic White pregnant women.

METHODS

Multivariate Adaptive Regression Splines (MARS) models were developed for preterm birth prediction for non-Hispanic Black, non-Hispanic White, and combined study samples derived from the CDC's Pregnancy Risk Assessment Monitoring System data (2012-2017). For each sample population, MARS models were trained and tested using 5-fold cross-validation. For each population, the Area Under the ROC Curve (AUC) was used to evaluate model performance, and variable importance for preterm birth prediction was computed.

RESULTS

Among 81,892 non-Hispanic Black and 277,963 non-Hispanic White live births (weighted sample), the best-performing MARS models showed high accuracy (AUC: 0.754-0.765) and similar-or-better performance for race/ethnicity-specific models compared to the combined model. The number of prenatal care visits, premature rupture of membrane, and medical conditions were more important than other variables in predicting preterm birth across the populations. Chronic stressors (e.g., low maternal education and intimate partner violence) and their correlates predicted preterm birth only for non-Hispanic Black women.

CONCLUSIONS

Our study findings reinforce that such mid or upstream determinants of health as chronic stressors should be targeted to reduce excess preterm birth risk among non-Hispanic Black women and ultimately narrow the persistent Black-White gap in preterm birth in the U.S.

Risk factors for maternal near-miss in an undeveloped province in south-central China, 2012-2022

OBJECTIVE

To explore the risk factors for maternal near-miss (MNM) using the WHO near-miss approach.

METHODS

Data were obtained from the Maternal Near-Miss Surveillance System in Hunan Province, China, 2012-2022. Multivariate logistic regression analysis (method: Forward, Wald, α = 0.05) and adjusted odds ratios (aORs) were used to identify risk factors for MNM.

RESULTS

Our study included 780,359 women with 731,185 live births, a total of 2461 (0.32%) MNMs, 777,846 (99.68%) non-MNMs, and 52 (0.006%) maternal deaths were identified. The MNM ratio was 3.37‰ (95%CI: 3.23-3.50). Coagulation/hematological dysfunction was the most common cause of MNM (75.66%). Results of multivariate logistic regression analysis showed risk factors for MNM: maternal age > = 30 years old (aOR > 1, P < 0.05), unmarried women (aOR = 2.21, 95%CI: 1.71-2.85), number of pregnancies > = 2 (aOR > 1, P < 0.05), nulliparity (aOR = 1.51, 95%CI: 1.32-1.72) or parity > = 3 (aOR = 1.95, 95%CI: 1.50-2.55), prenatal examinations < 5 times (aOR = 1.13, 95%CI: 1.01-1.27), and number of cesarean sections was 1 (aOR = 1.83, 95%CI: 1.64-2.04) or > = 2 (aOR = 2.48, 95%CI: 1.99-3.09).

CONCLUSION

The MNM ratio was relatively low in Hunan Province. Advanced maternal age, unmarried status, a high number of pregnancies, nulliparity or high parity, a low number of prenatal examinations, and cesarean sections were risk factors for MNM. Our study is essential for improving the quality of maternal health care and preventing MNM.

Maternal birth weight is an indicator of preterm delivery: the Japan environment and children's study

This study aimed to investigate the association between maternal birth weight (MBW) with preterm delivery (PTD) in the Japanese population. To this end, a total of 78,972 Japanese pregnant women were included in a prospective birth cohort study. Multiple logistic regression and multinominal logistic regression models were applied to investigate the associations of MBW with PTD (delivery from 22 to < 37 weeks of gestation), early PTD (delivery from 22 to < 34 weeks), and late PTD (delivery from 34 to < 37 weeks). The results showed that MBW was inversely associated with PTD, early PTD, and late PTD (p-for-trend < 0.0001, 0.0014, and < 0.0001, respectively). The adjusted odds ratios per each 500 g of MBW decrease were 1.167 (95% confidence interval [CI]: 1.118-1.218) for PTD, 1.174 (95% CI: 1.070-1.287) for early PTD and 1.151 (95% CI: 1.098-1.206) for late PTD. The effect size of the association of MBW with early PTD was similar to that with late PTD. This study demonstrated for the first time an association of a low MBW with PTD, early PTD, and late PTD in a Japanese nationwide cohort.

Poor Response to Gonadotropin Stimulation and Perinatal Outcomes in Fresh In Vitro Fertilization Embryo Transfer Cycles-A Retrospective Cohort Study

Objective: The objective was to examine the association between poor ovarian response to gonadotropin stimulation for in vitro fertilization (IVF) and adverse perinatal outcomes in singleton gestations in young patients. Methods: This was a retrospective cohort study including women aged 17-39 who underwent fresh embryo transfer and delivered a singleton neonate at a single center (pre-implantation genetic testing excluded) (2007-2022). Patients were classified as one of the following categories: poor responders-daily follicle-stimulating hormone (FSH) ≥ 150 IU yielding ≤ 3 retrieved oocytes; normal responders-4-15 oocytes; and high responders with ≥16 oocytes. The primary outcome was a composite of pre-eclampsia (mild or severe), small-for-gestational-age, gestational diabetes mellitus, and preterm birth (<37 weeks). We compared maternal and neonatal outcomes between the three groups. Multivariable logistic regression was used to control for confounders. Results: Overall, 507 women met the inclusion criteria. Of them, there were 44 (8.68%) poor responders, 342 (67.46%) normal responders, and 121 (23.87%) high responders. Poor responders, compared to normal and high responders, were characterized by a higher maternal age (34.64 ± 4.01 vs. 31.4 ± 5.04 vs. 30.01 ± 4.93, p < 0.001, respectively) and total FSH dosage (3028.41 ± 1792.05 IU vs. 2375.11 ± 1394.05 IU vs. 1869.31 ± 1089.63 IU, p < 0.001). The perinatal outcomes examined, including cesarean delivery (CD) rate and the composite outcome, were comparable between groups. Using multivariable logistic regression and adjusting for ovarian response group, maternal age, nulliparity, and estradiol level and endometrial thickness before ovulation triggering, poor response was not associated with CD rate or the composite outcome, with maternal age associated with CD (p = 0.005), and nulliparity with the composite outcome (p = 0.007). Similar results were obtained when comparing poor responders to each other group separately or to all other responders. Conclusions: Poor ovarian response is not associated with increased adverse maternal or neonatal outcomes.

Pre-pregnancy BMI, rate of gestational weight gain, and preterm birth among US Pacific Islander individuals

OBJECTIVE

The objective of this study was to examine the association between rate of gestational weight gain (GWG) and preterm birth (PTB) classified by pre-pregnancy BMI among Pacific Islander individuals in the United States.

METHODS

Pacific Islander mothers (n = 55,975) and singleton infants (22-41 gestational weeks) without congenital anomalies were included using data from the National Center for Health Statistics (2014-2018). PTB was compared by pre-pregnancy BMI among women in each stratum of rate of GWG using Cox proportional hazards models.

RESULTS

Compared with mothers with a rate of GWG within the guidelines, mothers with a rate of GWG below the guidelines and either pre-pregnancy underweight (adjusted hazard ratio [aHR] = 1.84, 95% CI: 1.10-3.06), healthy weight (aHR = 1.38, 95% CI: 1.15-1.65), obesity class I (aHR = 1.22, 95% CI: 0.97-1.52), or obesity class II (aHR = 1.43, 95% CI: 1.05-1.96) had an increased risk of PTB; mothers with a rate of GWG above the guidelines and either pre-pregnancy underweight (aHR = 1.57, 95% CI: 0.92-2.69) or obesity class II (aHR = 1.31, 95% CI: 0.98-1.76) had an increased risk of PTB.

CONCLUSIONS

The association between rate of GWG below or above the guidelines and PTB differs by pre-pregnancy BMI among Pacific Islander individuals.

Multilayer perceptron and support vector regression models for feline parturition date prediction

A crucial challenge in feline obstetric care is the accurate prediction of the parturition date during late pregnancy. The classic simple linear regression (SLR) model, which employed the fetal biparietal diameter (BPD) as the single input feature, was frequently applied for such prediction with limited accuracy. Since Multilayer Perceptron (MLP) and Support Vector Regression (SVR) are now two of the most potent scientific regression models, this study, for the first time, introduced such models as the new promising tools for feline parturition date prediction. The following features were candidate inputs for our models: biparietal diameter (BPD), litter size, and maternal weight. We observed and compared the performance results for each model. As the best-performed model, MLP delivered the highest coefficient score (0.972 ± 0.006), lowest mean absolute error score (1.110 ± 0.060), and lowest mean squared error score (1.540 ± 0.141), respectively. For the first time in this study, BPD, litter size, and maternal weight were considered the essential features for the innovative MLP and SVR modeling. With the optimized model parameters and the described analytical platform, further verification of these advanced models in feline obstetric practices is feasible.

Evaluating the relationship between conditional cash transfer programme on preterm births: a retrospective longitudinal study using the 100 million Brazilian cohort

BACKGROUND

Preterm births increase mortality and morbidity during childhood and later life, which is closely associated with poverty and the quality of prenatal care. Therefore, income redistribution and poverty reduction initiatives may be valuable in preventing this outcome. We assessed whether receipt of the Brazilian conditional cash transfer programme - Bolsa Familia Programme, the largest in the world - reduces the occurrence of preterm births, including their severity categories, and explored how this association differs according to prenatal care and the quality of Bolsa Familia Programme management.

METHODS

A retrospective cohort study was performed involving the first live singleton births to mothersenrolled in the 100 Million Brazilian Cohort from 2004 to 2015, who had at least one child before cohort enrollment. Only the first birth during the cohort period was included, but born from 2012 onward. A deterministic linkage with the Bolsa Familia Programme payroll dataset and a similarity linkage with the Brazilian Live Birth Information System were performed. The exposed group consisted of newborns to mothers who received Bolsa Familia from conception to delivery. Our outcomes were infants born with a gestational age < 37 weeks: (i) all preterm births, (ii) moderate-to-late (32-36), (iii) severe (28-31), and (iv) extreme (< 28) preterm births compared to at-term newborns. We combined propensity score-based methods and weighted logistic regressions to compare newborns to mothers who did and did not receive Bolsa Familia, controlling for socioeconomic conditions. We also estimated these effects separately, according to the adequacy of prenatal care and the index of quality of Bolsa Familia Programme management.

RESULTS

1,031,053 infants were analyzed; 65.9% of the mothers were beneficiaries. Bolsa Familia Programme was not associated with all sets of preterm births, moderate-to-late, and severe preterm births, but was associated with a reduction in extreme preterm births (weighted OR: 0.69; 95%CI: 0.63-0.76). This reduction can also be observed among mothers receiving adequate prenatal care (weighted OR: 0.66; 95%CI: 0.59-0.74) and living in better Bolsa Familia management municipalities (weighted OR: 0.56; 95%CI: 0.43-0.74).

CONCLUSIONS

An income transfer programme for pregnant women of low-socioeconomic status, conditional to attending prenatal care appointments, has been associated with a reduction in extremely preterm births. These programmes could be essential in achieving Sustainable Development Goals.

Is Parity a Risk Factor for Late Preterm Birth? Results from a Large Cohort Study

Most preterm births occur in the late preterm period. While prematurity-related adverse outcomes are significantly diminished when birth occurs during this period, these infants are still at increased risk of complications. Parity affects the incidence of obstetric complications. The purpose of this study was to determine whether parity impacts the risk of spontaneous late preterm birth (SLPTB) and associated complications. A retrospective observational cohort study was conducted. Patients were divided into three study groups according to parity. The primary outcome was the rate of SLPTB in each group. Secondary outcomes were unplanned cesarean delivery (UCD), prolonged third stage of labor respiratory distress syndrome (RDS), transient tachypnea of the newborn (TTN), intraventricular hemorrhage (IVH), neonatal hypoglycemia, duration of NICU admission, neonatal death, and composite adverse neonatal outcome (CANO). Primiparas were more likely to have SLPTB, UCD, and CANO compared to multiparas (2.6% vs. 1.9% OR 1.5 [1.3-1.7] p < 0.01) (4.1% vs. 1.3% OR 2.7 [1.2, 5.9] p < 0.01) (8.5% vs. 4.2 OR 2.1 [1.3-3.5] p = 0.002) and grandmultiparas (2.6% vs. 1.7% OR 1.4 [1.2-1.5] p < 0.001) 8.5% vs. 4.4% OR 2.0 [1.1, 3.8], p = 0.01) but no difference in UCD compared to grandmultiparas (4.1% vs. 3.3% OR 1.2 [0.6-2.7] p = 0.28). Primiparas are at increased risk of SLPTB and UCD, and this is accompanied by an increased risk of adverse neonatal outcomes.

Development and validation of a prediction model on spontaneous preterm birth in twin pregnancy: a retrospective cohort study

BACKGROUND

This study was conducted to develop and validate an individualized prediction model for spontaneous preterm birth (sPTB) in twin pregnancies.

METHODS

This a retrospective cohort study included 3845 patients who gave birth at the Chongqing Maternal and Child Health Hospital from January 2017 to December 2022. Both univariable and multivariable logistic regression analyses were performed to find factors associated with sPTB. The associations were estimated using the odds ratio (OR) and the 95% confidence interval (CI). Model performance was estimated using sensitivity, specificity, accuracy, area under the receiver operating characteristic curve (AUC) and decision curve analysis (DCA).

RESULTS

A total of 1313 and 564 cases were included in the training and testing sets, respectively. In the training set, univariate and multivariate logistic regression analysis indicated that age ≥ 35 years (OR, 2.28; 95% CI 1.67-3.13), pre-pregnancy underweight (OR, 2.36; 95% CI 1.60-3.47), pre-pregnancy overweight (OR, 1.67; 95% CI 1.09-2.56), and obesity (OR, 10.45; 95% CI, 3.91-27.87), nulliparity (OR, 0.58; 95% CI 0.41-0.82), pre-pregnancy diabetes (OR, 5.81; 95% CI 3.24-10.39), pre-pregnancy hypertension (OR, 2.79; 95% CI 1.44-5.41), and cervical incompetence (OR, 5.12; 95% CI 3.08-8.48) are independent risk factors for sPTB in twin pregnancies. The AUC of the training and validation set was 0.71 (95% CI 0.68-0.74) and 0.68 (95% CI 0.64-0.73), respectively. And then we integrated those risk factors to construct the nomogram.

CONCLUSIONS

The nomogram developed for predicting the risk of sPTB in pregnant women with twins demonstrated good performance. The prediction nomogram serves as a practical tool by including all necessary predictors that are readily accessible to practitioners.

Mode of Delivery and Neonatal Outcomes of Preterm Deliveries: A Retrospective Study in Greece

Background and Objectives: Preterm birth is a significant concern in obstetrics and neonatology since preterm neonates are at higher risk of various health complications and may require specialized care. The optimal mode of delivery in preterm birth is a matter of debate. This study aimed to evaluate the mode of delivery in preterm neonates and the associated neonatal outcomes. Material and Methods: This was a retrospective cohort study including all preterm neonates born between January 2010 and December 2020 at the 3rd Department of Obstetrics & Gynecology of Aristotle University of Thessaloniki, Greece. The mode of delivery in relation to gestational age groups and the cause of preterm birth were analyzed. Neonatal outcomes were also evaluated according to gestational age, indication and mode of delivery. Results: A total of 1167 preterm neonates were included in the study; the majority of them were delivered via cesarean section (76.1%). Most of the preterm neonates (n = 715; 61.3%) were delivered at 32+0-36+6 weeks, while cesarean section was the most common mode of delivery after 28+0 weeks. Furthermore, spontaneous onset of labor (OR: 6.038; 95% CI: 3.163-11.527; p < 0.001), multiple gestation (OR: 1.782; 95% CI: 1.165-2.227; p = 0.008) and fetal distress (OR: 5.326; 95% CI: 2.796-10.144; p < 0.001) were the main causes of preterm delivery at 32+0-36+6 weeks. The overall mortality rate was 8.1% among premature neonates. Regarding morbidity, 919 (78.7%) neonates were diagnosed with respiratory disorders, 129 (11.1%) with intraventricular hemorrhage and 30 (2.6%) with necrotizing enterocolitis. Early gestational age at delivery was the main risk factor of neonatal morbidity and mortality. Notably, the mode of delivery did not have any impact on neonatal survival (OR: 1.317; 95% CI: 0.759-2.284; p = 0.328), but preterm neonates born via cesarean section were at higher risk of respiratory disorders, compared to those born via vaginal delivery (OR: 2.208; 95% CI: 1.574-3.097; p < 0.001). Conclusions: Most preterm deliveries occurred in the moderate-to-late preterm period via cesarean section. Early gestational age at delivery was the main prognostic factor of neonatal morbidity and mortality, while the mode of delivery did not have any impact on neonatal survival. Future research on the mode of delivery of the preterm neonates is warranted to establish definitive answers for each particular gestational age.

Optimizing the timing of antenatal corticosteroid administration prior to anticipated preterm birth: A retrospective cohort study

OBJECTIVE

To examine suboptimal antenatal corticosteroid (ACS) administration based on indications and maternal-obstetrical factors.

METHODS

Women who prematurely delivered (24 + 0 to 36 + 6 gestational weeks) a viable neonate following ACS treatment between 2012 and 2019 were identified by a retrospective database review. The cohort was divided into patients in whom ACS administration was optimally timed (≥24 h to ≤7 days) or suboptimally timed (>7 days). The groups were compared for ACS indications and maternal, obstetrical, and neonatal parameters.

RESULTS

The cohort included 399 women. ACS timing was optimal in 233 patients (58%) and was associated with nulliparity (109 [46.8%] vs. 54 [32.5%], P = 0.004) and preterm premature rupture of membranes (89 [38.2%] vs. 45 [27.1%], P = 0.021). Suboptimal timing was associated with chronic hypertension (22 [9.4%] vs. 36 [21.7%], P < 0.001) and asymptomatic cervical shortening (23 [9.9%] vs. 26 [15.7%], P = 0.020). Optimal ACS timing was associated with higher neonatal intensive care unit admission (135 [58%] vs. 71 [42.8%], P = 0.003). On multivariate analysis, the adjusted odds ratio (aOR) of neonatal intensive care unit admission was 0.69 (95% confidence interval [CI], 0.58-0.83, P < 0.001) and 0.99 (95% CI, 0.99-1, P = 0.003) when adjusted for gestational age and birth weight, respectively. When adjusting for maternal age, the aOR for suboptimal ACS administraion due to chronic hypertension was 2.65 (95% CI, 1.49-4.72; P < 0.001).

CONCLUSION

Optimal timing of ACS varies based on different maternal characteristics and clinical indications. In the presence of certain parameters physicians tend to administer ACS suboptimally, diminishing its beneficial effect.

Interferon-stimulated gene 15 polymorphisms are associated with spontaneous preterm birth in Taiwanese women

PROBLEM

Immune and inflammatory responses are known to be major causes of preterm birth (PTB). The maternal genetic background plays an important role in the development of PTB. Interferon-stimulated gene 15 (ISG15) is an interferon-induced protein which can modulate immune cell activation and function. We aim to study if polymorphisms in the ISG15 gene are associated with spontaneous PTB (sPTB) risk in Taiwanese women.

METHOD OF STUDY

ISG15 rs4615788 C/G, rs1921 G/A, and rs8997 A/G polymorphisms were genotyped in a hospital-based study of 112 women with sPTB and 1120 term controls. The plasma concentrations of ISG15 were determined by enzyme-linked immunosorbent assay.

RESULTS

We found the ISG15 rs1921 G-rs8997 A haplotype was associated with decreased risk for PTB (χ2  = 6.26, p = .01, pc  = .04). The A/G genotype of ISG15 rs8997 polymorphism might have the potential to confer reduced risk of PTB women (χ2  = 4.09, p = .04, pc  = .08). Spontaneous PTB women displayed higher plasma ISG15 levels compared to term controls (p < .001). The plasma ISG15 levels among pregnant women with rs8997 A/G genotype were found significantly lower compared to G/G genotype (p = .03).

CONCLUSIONS

Women with the ISG15 rs1921 G-rs8997 A haplotype may associate with spontaneous PTB. These findings provide new insights into the etiology of preterm birth.

Prediction of Preterm Delivery Using Serum Ischemia Modified Albumin, Biglycan, and Decorin Levels in Women with Threatened Preterm Labor

OBJECTIVE

 The serum ischemia modified albumin (IMA), biglycan, and decorin levels of pregnant women who were hospitalized for threatened preterm labor were measured.

METHODS

 Fifty-one consecutive pregnant women with a single pregnancy between the 24th and 36th weeks with a diagnosis of threatened preterm labor were included in the present prospective cohort study.

RESULTS

 As a result of multivariate logistic regression analysis for predicting preterm delivery within 24 hours, 48 hours, 7 days, 14 days, ≤ 35 gestational weeks, and ≤ 37 gestational weeks after admission, area under the curve (AUC) (95% confidence interval [CI[) values were 0.95 (0.89-1.00), 0.93 (0.86-0.99), 0.91 (0.83-0.98), 0.92 (0.85-0.99), 0.82 (0.69-0.96), and 0.89 (0.80-0.98), respectively. In the present study, IMA and biglycan levels were found to be higher and decorin levels lower in women admitted to the hospital with threatened preterm labor and who gave preterm birth within 48 hours compared with those who gave birth after 48 hours.

CONCLUSION

 In pregnant women admitted to the hospital with threatened preterm labor, the prediction preterm delivery of the combined model created by adding IMA, decorin, and biglycan in addition to the TVS CL measurement was higher than the TVS CL measurement alone.

CLINICAL TRIAL REGISTRATION

 The present trial was registered at ClinicalTrials.gov, number NCT04451928.

Perinatal health effects of herbicides exposures in the United States: the Heartland Study, a Midwestern birth cohort study

BACKGROUND

The objective of the Heartland Study is to address major knowledge gaps concerning the health effects of herbicides on maternal and infant health. To achieve this goal, a two-phased, prospective longitudinal cohort study is being conducted. Phase 1 is designed to evaluate associations between biomarkers of herbicide concentration and pregnancy/childbirth outcomes. Phase 2 is designed to evaluate potential associations between herbicide biomarkers and early childhood neurological development.

METHODS

People (target enrollment of 2,000) who are seeking prenatal care, are ages 18 or older, and are ≤ 20 + 6 weeks gestation will be eligible for recruitment. The Heartland Study will utilize a combination of questionnaire data and biospecimen collections to meet the study objectives. One prenatal urine and buccal sample will be collected per trimester to assess the impact of herbicide concentration levels on pregnancy outcomes. Infant buccal specimens will be collected post-delivery. All questionnaires will be collected by trained study staff and clinic staff will remain blinded to all individual level research data. All data will be stored in a secure REDCap database. Hospitals in the agriculturally intensive states in the Midwestern region will be recruited as study sites. Currently participating clinical sites include Indiana University School of Medicine- affiliated Hospitals in Indianapolis, Indiana; Franciscan Health Center in Indianapolis, Indiana; Gundersen Lutheran Medical Center in La Crosse, Wisconsin, and University of Iowa in Iowa City, Iowa. An anticipated 30% of the total enrollment will be recruited from rural areas to evaluate herbicide concentrations among those pregnant people residing in the rural Midwest. Perinatal outcomes (e.g. birth outcomes, preterm birth, preeclampsia, etc.) will be extracted by trained study teams and analyzed for their relationship to herbicide concentration levels using appropriate multivariable models.

DISCUSSION

Though decades of study have shown that environmental chemicals may have important impacts on the health of parents and infants, there is a paucity of prospective longitudinal data on reproductive impacts of herbicides. The recent, rapid increases in herbicide use across agricultural regions of the United States necessitate further research into the human health effects of these chemicals, particularly in pregnant people. The Heartland Study provides an invaluable opportunity to evaluate health impacts of herbicides during pregnancy and beyond.

TRIAL REGISTRATION

The study is registered at clinicaltrials.gov, NCT05492708 with initial registration and release 05 August, 2022.

Reducing the Rate of Premature Births through Early Diagnosis and Pregnancy-Adapted Treatment of Hypothyroidism

Introduction

The aim of this study was to determine the extent to which regular monitoring of maternal free thyroxine level and pregnancy-adapted L-thyroxine replacement therapy before and during pregnancy in patients with existing or newly diagnosed latent and manifest hypothyroidism as well as hypothyroxinemia can influence the rate of premature births.

Materials and Methods

This is a retrospective cohort study assessing 1440 pseudonymized survey questionnaires to evaluate the risks of premature birth with two study groups from the same medical practice, and a nationally recruited control group. Study group A (n = 360) had already been taking L-thyroxine prior to conception, study group B (n = 580) started taking it after conception. Both study groups had a maximum gestational age of 12 + 0 GW. In the study groups, TSH and free thyroxine levels were determined regularly for dose adjustment purposes. The aim was to keep the free thyroxine level in the euthyroid hyperthyroxinemic range within the pregnancy adapted reference range. The control group (n = 500) had taken L-thyroxine during pregnancy according to criteria that were not known, as the questionnaire did not include any questions regarding this matter. Taking other risk factors into account, the influence of pregnancy-adapted L-thyroxine replacement therapy on the rate of premature births was determined using logistic regression analysis.

Results

Compared with the control group, the premature birth rate was 70% lower (p < 0.0001) in study group A and 42% lower in study group B (p = 0.0086), while the odds ratio, at 3.46, was particularly significant in study group A. High blood pressure (odds ratio 5.21), body mass index per kg/m 2 (odds ratio 0.91) and S. p. premature birth were identified as other independent risk factors.

Conclusion

The results show an association between more intensive thyroid diagnostics and pregnancy-adapted L-thyroxine replacement therapy and a decrease in premature births. Further studies should be conducted to confirm these results.

Exploring the association of parity and its interaction with history of preterm delivery on gestational duration

PURPOSE

Preterm delivery is a major cause of child mortality. While the relationship between parity and preterm delivery is known, its association with gestational duration and variability remains underexplored. Differences in variance may suggest interaction with other well-established risk factors.

METHODS

With 1.1 million spontaneous deliveries (1990-2012) from the Swedish Medical Birth Register, we assessed while accounting for potential confounders the effects of parity on the mean and variance of gestational duration, and its possible interactions with history of preterm delivery. Pedigrees allowed to account for nonobserved, shared confounders using linear mixed models.

RESULTS

Parity has a modest association with mean gestational duration, but a large effect on its variance. For example, the first pregnancy had the shortest mean gestational duration, 0.29 days shorter (95% CI: -0.33, -0.25) than the second, and the largest variance (σ2 = 135 days2). Accounting for shared unobserved confounders highlighted a group effect bias, likely linked to the mothers' total number of offspring. Parity interacts with other risk factors, including previous preterm delivery where the magnitude of its effect increases with parity (up to 4.6 days effect difference).

CONCLUSIONS

Nonshared factors across a mother's pregnancies highlight parity's importance to gain insight into the mechanisms governing the timing of delivery.

Contributions of CenteringPregnancy to women's health behaviours, health literacy, and health care use in the Netherlands

The objective of this study was to assess the effects of CenteringPregnancy (CP) in the Netherlands on different health outcomes. A stepped wedged cluster randomized trial was used, including 2132 women of approximately 12 weeks of gestation, from thirteen primary care midwifery centres in and around Leiden, Netherlands. Data collection was done through self-administered questionnaires. Multilevel intention-to-treat analysis and propensity score matching for the entire group and separately for nulliparous- and multiparous women were employed. The main outcomes were: health behaviour, health literacy, psychological outcomes, health care use, and satisfaction with care. Women's participation in CP is associated with lower alcohol consumption after birth (OR = 0.59, 95 %CI 0.42-0.84), greater consistency with norms for healthy eating and physical activity (β = 0.19, 95 %CI 0.02-0.37), and higher knowledge about pregnancy (β = 0.05, 95 %CI 0.01-0.08). Compared to the control group, nulliparous women who participating in CP reported better compliance to the norm for healthy eating and physical activity (β = 0.28, 95 %CI0.06-0.51)) and multiparous CP participants consumed less alcohol after giving birth (OR = 0.42, 95 %CI 0.23-0.78). Health care use and satisfaction rates were significantly higher among CP participants. A non-significant trend toward lower smoking rates was documented among CP participants. Overall, the results of this study reveal a positive (postpartum) impact on fostering healthy behaviours among participants.

Prediction and Prevention of Preterm Birth: Secondary Analysis of a Randomized Intervention Trial

Our objective was to evaluate whether pregnancy is prolonged by the use of a proteomics-based maternal serum screening test followed by treatment interventions. This is a secondary analysis of the PREVENT-PTB randomized trial comparing screening with the PreTRM test versus no screening. The primary trial analysis found no significant between-group difference in the preterm birth rate. Rather than considering a dichotomous outcome (preterm versus term), we treated gestational age at birth as a continuous variable using survival analysis. We also evaluated between-group difference in NICU length of stay and duration of respiratory support. Results indicated that pregnancy was significantly prolonged in subjects screened with the PreTRM test compared to controls (adjusted hazard ratio 0.53, 95% confidence interval 0.36-0.78, p < 0.01). Newborns of screened subjects had significantly shorter NICU stays but no significant decrease in duration of respiratory support. In the PreTRM screen-positive group, interventions that were associated with pregnancy prolongation included care management and low-dose aspirin but not 17-hydroxyprogesterone caproate. We conclude that screening with the PreTRM test followed by interventions for screen-positive pregnancies may prolong pregnancy and reduce NICU LOS, but these observations need to be confirmed by additional research.

New Interpretation of Neonatal Outcomes by Phenotypically Classified Preterm Syndrome: A Retrospective Cohort Study

OBJECTIVE

The global aim to lower preterm birth rates has been hampered by the insufficient and incomplete understanding of its etiology, classification, and diagnosis. This study was designed to evaluate the association of phenotypically classified preterm syndromes with neonatal outcomes; to what extent would these outcomes be modified after the obstetric interventions, including use of glucocorticoid, magnesium sulfate, and progesterone.

METHODS

This was a retrospective cohort study conducted at Tongji Hospital (composed of Main Branch, Optical Valley Branch and Sino-French New City Branch) in Wuhan. A total of 900 pregnant women and 1064 neonates were retrospectively enrolled. The outcomes were the distribution of different phenotypes among parturition signs and pathway to delivery, the association of phenotypically classified clusters with short-term unfavorable neonatal outcomes, and to what extent these outcomes could be modified by obstetric interventions.

RESULTS

Eight clusters were identified using two-step cluster analysis, including premature rupture of fetal membranes (PPROM) phenotype, abnormal amniotic fluid (AF) phenotype, placenta previa phenotype, mixed condition phenotype, fetal distress phenotype, preeclampsia-eclampsia & hemolysis, elevated liver enzymes, and low platelets syndrome (PE-E&HELLP) phenotype, multiple fetus phenotype, and no main condition phenotype. Except for no main condition phenotype, the other phenotypes were associated with one or more complications, which conforms to the clinical practice. Compared with no main condition phenotype, some phenotypes were significantly associated with short-term adverse neonatal outcomes. Abnormal AF phenotype, mixed condition phenotype, PE-E&HELLP phenotype, and multiple fetus phenotype were risk factors for neonatal small-for gestation age (SGA); placenta previa phenotype was not associated with adverse outcomes except low APGAR score being 0-7 at one min; mixed condition phenotype was associated with low APGAR scores, SGA, mechanical ventilation, and grade HI-W intraventricular hemorrhage (IVH); fetal distress phenotype was frequently associated with neonatal SGA and mechanical ventilation; PE-E&HELLP phenotype was correlated with low APGAR score being 0-7 at one min, SGA and neonatal intensive care unit (NICU) admission; multiple fetus phenotype was not a risk factor for the outcomes included except for SGA. Not all neonates benefited from obstetric interventions included in this study.

CONCLUSION

Our research disclosed the independent risk of different preterm phenotypes for adverse pregnancy outcomes. This study is devoted to putting forward the paradigm of classifying preterm birth phenotypically, with the ultimate purpose of defining preterm phenotypes based on multi-center studies and diving into the underlying mechanisms.

Abrupt perturbation and delayed recovery of the vaginal ecosystem following childbirth

The vaginal ecosystem is closely tied to human health and reproductive outcomes, yet its dynamics in the wake of childbirth remain poorly characterized. Here, we profile the vaginal microbiota and cytokine milieu of participants sampled longitudinally throughout pregnancy and for at least one year postpartum. We show that delivery, regardless of mode, is associated with a vaginal pro-inflammatory cytokine response and the loss of Lactobacillus dominance. By contrast, neither the progression of gestation nor the approach of labor strongly altered the vaginal ecosystem. At 9.5-months postpartum-the latest timepoint at which cytokines were assessed-elevated inflammation coincided with vaginal bacterial communities that had remained perturbed (highly diverse) from the time of delivery. Time-to-event analysis indicated a one-year postpartum probability of transitioning to Lactobacillus dominance of 49.4%. As diversity and inflammation declined during the postpartum period, dominance by L. crispatus, the quintessential health-associated commensal, failed to return: its prevalence before, immediately after, and one year after delivery was 41%, 4%, and 9%, respectively. Revisiting our pre-delivery data, we found that a prior live birth was associated with a lower odds of L. crispatus dominance in pregnant participants-an outcome modestly tempered by a longer ( > 18-month) interpregnancy interval. Our results suggest that reproductive history and childbirth in particular remodel the vaginal ecosystem and that the timing and degree of recovery from delivery may help determine the subsequent health of the woman and of future pregnancies.

Predictors of adverse short-term outcomes in late preterm infants

BACKGROUND

Infants born between 34 weeks and 36 weeks and 6 days of gestation are defined as late preterm infants (LPIs), and they account for approximately 74% of all premature births. Preterm birth (PB) remains the leading cause of infant mortality and morbidity worldwide.

AIM

To analyse short-term morbidity and mortality and identify predictors of adverse outcomes in late preterm infants.

PATIENTS AND METHODS

In this retrospective study, we evaluated adverse short-term outcomes of LPIs admitted to the Intensive Care Unit (ICU), Clinic for Children's Diseases, University Clinical Center Tuzla, between 01.01.2020 and 31.12.2022. The analysed data included sex, gestational age, parity, birth weight, Apgar score (i.e., assessment of vitality at birth in the first and fifth minutes after birth), and length of hospitalization in NICU, as well as short-term outcome data. Maternal risk factors we observed were: age of mother, parity, maternal morbidity during pregnancy, complications and treatment during pregnancy. LPIs with major anatomic malformations were excluded from the study. Logistic regression analysis was used to identify risk factors for neonatal morbidity among LPIs.

RESULTS

We analysed data from 154 late preterm newborns, most of whom were male (60%), delivered by caesarean Sect. (68.2%) and from nulliparous mothers (63.6%). Respiratory complications were the most common outcome among all subgroups, followed by CNS morbidity, infections and jaundice requiring phototherapy. The rate of almost all of the complications in the late-preterm group decreased as gestational age increased from 34 to 36 weeks. Birth weight (OR: 1,2; 95% CI: 0,9 - 2,3; p = 0,0313) and male sex (OR: 2,5; 95% CI: 1,1-5,4; p = 0,0204) were significantly and independently associated with an increased risk for respiratory morbidity, and gestational weeks and male sex were associated with infectious morbidity. None of the risk factors analysed herein were predictors of CNS morbidity in LPIs.

CONCLUSION

A younger gestational age at birth is associated with a greater risk of short-term complications among LPIs, thus highlighting the need for increased knowledge about the epidemiology of these late preterm births. Understanding the risks of late preterm birth is critical to optimizing clinical decision-making, enhancing the cost-effectiveness of endeavours to delay delivery during the late preterm period, and reducing neonatal morbidity.

Association between Parity and Preterm Birth-Retrospective Analysis from a Single Center in Poland

Preterm births and parity are two medical areas that seem to be entirely different from each other. The aim of this study was to analyze the relationships between parity and maternal and neonatal outcomes associated with preterm birth. This study involved a retrospective analysis of electronic medical records from St. Sophia Hospital in Warsaw (Poland). This study was conducted among women who gave birth to preterm infants between 1 January 2017 and 31 December 2021. A total of 2043 cases of preterm births were included in the final analysis. A higher odds ratio of preterm birth in primiparas was found in women living in a city/town (OR = 1.56) and having secondary (OR = 1.46) and higher education (OR = 1.82). Multiparas who gave birth to preterm infants were more frequently diagnosed with gestational diabetes (19.69%) than primiparas. Multiparas were more likely to give birth to preterm infants who received an Apgar score of ≤7 both at 1 and 5 min after birth (25.80% and 15.34%). The results of our study emphasize the differences between primiparas and multiparas who give birth to preterm infants. Knowledge of these differences is essential to improve the perinatal care provided to mothers and their infants.

Preterm Birth Among Intrapartum Cesarean Deliveries at Public Hospitals in Southern Ethiopia: A Multicenter Retrospective Analysis of Risk Factors

Purpose

Although the underlying causes for preterm birth are thought to be multifactorial irrespective of delivery mode, no study investigated its risk factors amongst cesarean deliveries (CD). Thus, we aimed to identify potential risk factors for the occurrence of preterm birth (PTB) among intrapartum CD.

Methods

Data from 1659 singleton intrapartum CDs were retrospectively recruited using medical records and an obstetric database. Gestational age was calculated using the last menstrual period (LMP) and ultrasound report of early onset pregnancy. A multivariable logistic regression analysis was performed to identify potential risk factors associated with PTB. Odds ratios (ORs) and 95% confidence intervals (95% CI) were used. Statistical analysis was performed using SPSS version 26.0.

Results

In this study, the prevalence of PTB among intrapartum CD was 6.1% (95% CI: 4.9, 7.2%). In the multivariable logistic regression model; grand parity ≥5 (adjusted odds ratio (AOR) = 2.43, 95% CI: 1.72-4.73), maternal age <20 years (AOR=2.63, 95% CI, 1.03-6.71), maternal age ≥35 years (AOR=3.83, 95% CI, 1.49-5.35), cesarean section scar ≥2 (AOR=4.86, 95% CI: 2.68-8.94), antepartum hemorrhage (AOR=4.37, 95% CI: 2.22-8.63), pregnancy-induced hypertension (AOR=2.92, 95% CI: 1.41-6.04), and premature rupture of membranes (AOR=4.56; 95% CI: 1.95-10.65) were significantly associated with PTB.

Conclusion

The current study showed an association between PTB and a multitude of obstetric variables, including grand parity ≥5, CS scar ≥2, antepartum hemorrhage, pregnancy-induced hypertension, and premature rupture of the membrane. Understanding these factors could help to implement improved quality of obstetric and neonatal care to increase survival and reduce morbidity among preterm birth.

Multiomic signals associated with maternal epidemiological factors contributing to preterm birth in low- and middle-income countries

Preterm birth (PTB) is the leading cause of death in children under five, yet comprehensive studies are hindered by its multiple complex etiologies. Epidemiological associations between PTB and maternal characteristics have been previously described. This work used multiomic profiling and multivariate modeling to investigate the biological signatures of these characteristics. Maternal covariates were collected during pregnancy from 13,841 pregnant women across five sites. Plasma samples from 231 participants were analyzed to generate proteomic, metabolomic, and lipidomic datasets. Machine learning models showed robust performance for the prediction of PTB (AUROC = 0.70), time-to-delivery (r = 0.65), maternal age (r = 0.59), gravidity (r = 0.56), and BMI (r = 0.81). Time-to-delivery biological correlates included fetal-associated proteins (e.g., ALPP, AFP, and PGF) and immune proteins (e.g., PD-L1, CCL28, and LIFR). Maternal age negatively correlated with collagen COL9A1, gravidity with endothelial NOS and inflammatory chemokine CXCL13, and BMI with leptin and structural protein FABP4. These results provide an integrated view of epidemiological factors associated with PTB and identify biological signatures of clinical covariates affecting this disease.

Predicting Spontaneous Pre-term Birth Risk Is Improved When Quantitative Ultrasound Data Are Included With Historical Clinical Data

OBJECTIVE

Predicting women at risk for spontaneous pre-term birth (sPTB) has been medically challenging because of the lack of signs and symptoms of pre-term birth until interventions are too late. We hypothesized that prediction of the sPTB risk level is enhanced when using both historical clinical (HC) data and quantitative ultrasound (QUS) data compared with using only HC data. HC data defined herein included birth history prior to that of the current pregnancy as well as, from the current pregnancy, a clinical cervical length assessment and physical examination data.

METHODS

The study population included 248 full-term births (FTBs) and 26 sPTBs. QUS scans (Siemens S2000 and MC9-4) were performed by registered diagnostic medical sonographers using a standard cervical length approach. Two cervical QUS scans were conducted at 20 ± 2 and 24 ± 2 wk of gestation. Multiple QUS features were evaluated from calibrated raw radiofrequency backscattered ultrasonic signals. Two statistical models designed to determine sPTB risk were compared: (i) HC data alone and (ii) combined HC and QUS data. Model comparisons included a likelihood ratio test, cross-validated receiver operating characteristic area under the curve, sensitivity and specificity. The study's birth outcomes were only FTBs and sPTBs; medically induced pre-term births were not included.

DISCUSSION

Combined HC and QUS data identified women at risk of sPTB with better AUC (0.68, 95% confidence interval [CI]: 0.57-0.78) compared with HC data alone (0.53, 95% CI: 0.40-0.66) and HC data + cervical length at 18-20 wk of gestation (average AUC = 0.51, 95% CI: 0.38-0.64). A likelihood ratio test for significance of QUS features in the classification model was highly statistically significant (p < 0.01).

CONCLUSION

Even with only 26 sPTBs among 274 births, value was added in predicting sPTB when QUS data were included with HC data.

County-Level Maternal Vulnerability and Preterm Birth in the US

Importance

Appreciation for the effects of neighborhood conditions and community factors on perinatal health is increasing. However, community-level indices specific to maternal health and associations with preterm birth (PTB) have not been assessed.

Objective

To examine the association of the Maternal Vulnerability Index (MVI), a novel county-level index designed to quantify maternal vulnerability to adverse health outcomes, with PTB.

Design, Setting, and Participants

This retrospective cohort study used US Vital Statistics data from January 1 to December 31, 2018. Participants included 3 659 099 singleton births at 22 plus 0/7 to 44 plus 6/7 weeks of gestation born in the US. Analyses were conducted from December 1, 2021, through March 31, 2023.

Exposure

The MVI, a composite measure of 43 area-level indicators, categorized into 6 themes reflecting physical, social, and health care landscapes. Overall MVI and theme were stratified by quintile (very low to very high) by maternal county of residence.

Main Outcomes and Measures

The primary outcome was PTB (gestational age <37 weeks). Secondary outcomes were PTB categories: extreme (gestational age ≤28 weeks), very (gestational age 29-31 weeks), moderate (gestational age 32-33 weeks), and late (gestational age 34-36 weeks). Multivariable logistic regression quantified associations of MVI, overall and by theme, with PTB, overall and by PTB category.

Results

Among 3 659 099 births, 298 847 (8.2%) were preterm (male, 51.1%; female, 48.9%). Maternal race and ethnicity included 0.8% American Indian or Alaska Native, 6.8% Asian or Pacific Islander, 23.6% Hispanic, 14.5% non-Hispanic Black, 52.1% non-Hispanic White, and 2.2% with more than 1 race. Compared with full-term births, MVI was higher for PTBs across all themes. Very high MVI was associated with increased PTB in unadjusted (odds ratio [OR], 1.50 [95% CI, 1.45-1.56]) and adjusted (OR, 1.07 [95% CI, 1.01-1.13]) analyses. In adjusted analyses of PTB categories, MVI had the largest association with extreme PTB (adjusted OR, 1.18 [95% CI, 1.07-1.29]). Higher MVI in the themes of physical health, mental health and substance abuse, and general health care remained associated with PTB overall in adjusted models. While the physical health and socioeconomic determinant themes were associated with extreme PTB, physical health, mental health and substance abuse, and general health care themes were associated with late PTB.

Conclusions and Relevance

The findings of this cohort study suggest that MVI was associated with PTB even after adjustment for individual-level confounders. The MVI is a useful measure for county-level PTB risk that may have policy implications for counties working to lower preterm rates and improve perinatal outcomes.

Acculturation Experiences and Preterm Birth in Berlin: Does Acculturative Stress Contribute to Preterm Birth?

Acculturation and acculturative stress are potential risk factors for adverse perinatal outcomes. This study investigates whether and how acculturative stress affects preterm birth (PTB) in a sample of migrant women in Berlin. We interviewed 955 women who recently gave birth using standardized questionnaires (Frankfurt Acculturation Scale and Acculturative Stress Index). Multivariable logistic regression analyses assessed the effects of acculturation and acculturative stress on PTB. Women with migrant backgrounds did not have significantly higher PTB rates than German natives. First-generation migrants experienced higher acculturative stress levels than second-generation migrants, 38.8% vs. 13.2%. Acculturative stress could not be identified as a risk factor for PTB in our sample. These results need to be considered in the context of an international city and the wide use of antenatal care services in our population, which could be responsible for similarly good perinatal outcomes and highlights the potential of good access to perinatal care for vulnerable groups.

Identification of novel cell-free RNAs in maternal plasma as preterm biomarkers in combination with placental RNA profiles

BACKGROUND

Preterm birth (PTB) is the main driver of newborn deaths. The identification of pregnancies at risk of PTB remains challenging, as the incomplete understanding of molecular mechanisms associated with PTB. Although several transcriptome studies have been done on the placenta and plasma from PTB women, a comprehensive description of the RNA profiles from plasma and placenta associated with PTB remains lacking.

METHODS

Candidate markers with consistent trends in the placenta and plasma were identified by implementing differential expression analysis using placental tissue and maternal plasma RNA-seq datasets, and then validated by RT-qPCR in an independent cohort. In combination with bioinformatics analysis tools, we set up two protein-protein interaction networks of the significant PTB-related modules. The support vector machine (SVM) model was used to verify the prediction potential of cell free RNAs (cfRNAs) in plasma for PTB and late PTB.

RESULTS

We identified 15 genes with consistent regulatory trends in placenta and plasma of PTB while the full term birth (FTB) acts as a control. Subsequently, we verified seven cfRNAs in an independent cohort by RT-qPCR in maternal plasma. The cfRNA ARHGEF28 showed consistence in the experimental validation and performed excellently in prediction of PTB in the model. The AUC achieved 0.990 for whole PTB and 0.986 for late PTB.

CONCLUSIONS

In a comparison of PTB versus FTB, the combined investigation of placental and plasma RNA profiles has shown a further understanding of the mechanism of PTB. Then, the cfRNA identified has the capacity of predicting whole PTB and late PTB.

Maternal Plasma RNA in First Trimester Nullipara for the Prediction of Spontaneous Preterm Birth ≤ 32 Weeks: Validation Study

The first-trimester prediction of spontaneous preterm birth (sPTB) has been elusive, and current screening is heavily dependent on obstetric history. However, nullipara lack a relevant history and are at higher risk for spontaneous (s)PTB ≤ 32 weeks compared to multipara. No available objective first-trimester screening test has proven a fair predictor of sPTB ≤ 32 weeks. We questioned whether a panel of maternal plasma cell-free (PCF) RNAs (PSME2, NAMPT, APOA1, APOA4, and Hsa-Let-7g) previously validated at 16-20 weeks for the prediction of sPTB ≤ 32 weeks might be useful in first-trimester nullipara. Sixty (60) nulliparous women (40 with sPTB ≤ 32 weeks) who were free of comorbidities were randomly selected from the King's College Fetal Medicine Research Institute biobank. Total PCF RNA was extracted and the expression of panel RNAs was quantitated by qRT-PCR. The analysis employed, primarily, multiple regression with the main outcome being the prediction of subsequent sPTB ≤ 32 weeks. The test performance was judged by the area under the curve (AUC) using a single threshold cut point with observed detection rates (DRs) at three fixed false positive rates (FPR). The mean gestation was 12.9 ± 0.5 weeks (range 12.0-14.1 weeks). Two RNAs were differentially expressed in women destined for sPTB ≤ 32 weeks: APOA1 (p < 0.001) and PSME2 (p = 0.05). APOA1 testing at 11-14 weeks predicted sPTB ≤ 32 weeks with fair to good accuracy. The best predictive model generated an AUC of 0.79 (95% CI 0.66-0.91) with observed DRs of 41%, 61%, and 79% for FPRs of 10%, 20%, and 30%, including crown-rump length, maternal weight, race, tobacco use, and age.

Impact of sedentary behavior and emotional support on prenatal psychological distress and birth outcomes during the COVID-19 pandemic

Abstract.

BACKGROUND

Studies have reported mixed findings regarding the impact of the coronavirus disease 2019 (COVID-19) pandemic on pregnant women and birth outcomes. This study used a quasi-experimental design to account for potential confounding by sociodemographic characteristics.

METHODS

Data were drawn from 16 prenatal cohorts participating in the Environmental influences on Child Health Outcomes (ECHO) program. Women exposed to the pandemic (delivered between 12 March 2020 and 30 May 2021) (n = 501) were propensity-score matched on maternal age, race and ethnicity, and child assigned sex at birth with 501 women who delivered before 11 March 2020. Participants reported on perceived stress, depressive symptoms, sedentary behavior, and emotional support during pregnancy. Infant gestational age (GA) at birth and birthweight were gathered from medical record abstraction or maternal report.

RESULTS

After adjusting for propensity matching and covariates (maternal education, public assistance, employment status, prepregnancy body mass index), results showed a small effect of pandemic exposure on shorter GA at birth, but no effect on birthweight adjusted for GA. Women who were pregnant during the pandemic reported higher levels of prenatal stress and depressive symptoms, but neither mediated the association between pandemic exposure and GA. Sedentary behavior and emotional support were each associated with prenatal stress and depressive symptoms in opposite directions, but no moderation effects were revealed.

CONCLUSIONS

There was no strong evidence for an association between pandemic exposure and adverse birth outcomes. Furthermore, results highlight the importance of reducing maternal sedentary behavior and encouraging emotional support for optimizing maternal health regardless of pandemic conditions.

Birth equity on the front lines: Impact of a community-based doula program in Brooklyn, NY

BACKGROUND

We assessed whether participation in Healthy Start Brooklyn's By My Side Birth Support Program-a maternal-health program providing community-based doula support during pregnancy, labor and delivery, and the early postpartum period-was associated with improved birth outcomes. By My Side takes a strength-based approach that aligns with the doula principles of respecting the client's autonomy, providing culturally appropriate care without judgment or conditions, and promoting informed decision making.

METHODS

Using a matched cohort design, birth certificate records for By My Side participants from 2010 through 2017 (n = 603) were each matched to three controls who also lived in the program area (n = 1809). Controls were matched on maternal age, race/ethnicity, education level, and trimester of prenatal-care initiation, using the simple random sampling method. The sample was restricted to singleton births. The odds of preterm birth, low birthweight, and cesarean birth were estimated, using conditional logistic regression.

RESULTS

By My Side participants had lower odds of having a preterm birth (5.6% vs 11.9%, P < .0001) or a low-birthweight baby (5.8% vs 9.7%, P = .0031) than controls. There was no statistically significant difference in the odds of cesarean delivery.

CONCLUSION

Participation in the By My Side Birth Support Program was associated with lower odds of preterm birth and low birthweight for participants, who were predominantly Black and Hispanic. Investing in doula services is an important way to address birth inequities among higher risk populations such as birthing people of color and those living in poverty. It could also help shape a new vision of the maternal-health system, placing the needs and well-being of birthing people at the center.

A decrease in endometrial thickness before embryo transfer is not associated with preterm birth and placenta-mediated pregnancy complications

RESEARCH QUESTION

Does a decrease in endometrial thickness (compaction ≥10%) before embryo transfer prognosticate the risk for preterm birth and placenta-mediated pregnancy complications among IVF pregnancies?

DESIGN

Retrospective cohort study at a large private fertility practice. Patients with a singleton live birth after a fresh or frozen embryo transfer between 2016 and 2019 were included. The primary outcome was preterm birth (delivery before 37 weeks gestational age). Secondary outcomes included gestational hypertension, pre-eclampsia, intrauterine growth restriction and placental abruption.

RESULTS

Of the 252 patients that met the study criteria, 122 (48%) demonstrated endometrial compaction (≥10%) and 130 (52%) did not. Age, body mass index (BMI), parity, history of preterm birth or history of pre-existing maternal conditions between the compaction and no-compaction groups were not significantly different. The overall prevalence of placenta-mediated complications across all participants was 25% (n = 62). The number of preterm births between the compaction and no-compaction groups (13% and 6%, respectively, P = 0.09) as well as the prevalence of placenta-mediated complications (29.5% and 20%, respectively, P = 0.08) were not significantly different. Findings for the primary outcome (preterm birth) persisted even after adjustment for potential confounding variables, including maternal age, parity, BMI, embryo score and type of embryo transfer (fresh versus frozen) (adjusted OR 1.86, 95% CI 0.64 to 5.38).

CONCLUSIONS

Endometrial compaction (or decrease in endometrial thickness) before embryo transfer is not associated with preterm birth or placenta-mediated pregnancy complications.

Midtrimester Cervical Length in Low-Risk Nulliparous Women for the Prediction of Spontaneous Preterm Birth: Should We Consider a New Definition of Short Cervix?

OBJECTIVE

The study aimed to estimate the predictive value of midtrimester cervical length (CL) and the optimal cut-off of CL that should be applied with asymptomatic nulliparous women for the prediction of spontaneous preterm birth (sPTB).

STUDY DESIGN

This is a prospective cohort study of asymptomatic nulliparous women with a singleton gestation. Participants underwent CL measurement by transvaginal ultrasound between 20 and 24 weeks of gestation. The participants and their health care providers remained blinded to the results of CL measurement. The primary outcomes were sPTB before 35 weeks and sPTB before 37 weeks. Receiver operating characteristics (ROC) curve analyses were performed. Analyses were repeated by using multiples of median (MoM) of CL adjusted for gestational age.

RESULTS

Of 796 participants, the mean midtrimester CL was 40 ± 6 mm with a 1st, 5th, and 10th percentile of 25, 29, and 32 mm, respectively. ROC curve analyses suggest that a cut-off of 30 mm was the optimal CL to predict sPTB before 35 weeks (area under the ROC curve [AUC]: 0.70, 95% confidence interval [CI]: 0.56-0.85) and before 37 weeks (AUC: 0.70, 95% CI: 0.59-0.80). Midtrimester CL <30 mm could detect 35% of all sPTB before 35 weeks at a false-positive rate of 5% (relative risk: 9.1, 95% CI: 3.5-23.5, p < 0.001). We observed similar results using a cut-off of CL <0.75 MoM adjusted for gestational age.

CONCLUSION

A midtrimester CL cut-off of 30 mm (instead of 25 mm), or CL less than 0.75 MoM, should be used to identify nulliparous women at high risk of sPTB.

KEY POINTS

· The optimal CL cut-off for the prediction of sPTB is 30 mm in nulliparous women.. · In nulliparous women, a midtrimester CL < 30 mm is highly associated with sPTB before 35 and 37 weeks.. · A midtrimester of CL <30 mm (5th percentile) should define a short cervix in asymptomatic nulliparous women..

Haematological changes from conception to childbirth: An indicator of major pregnancy complications

BACKGROUND

About 800 women die every day worldwide from pregnancy-related complications, including excessive blood loss, infections and high-blood pressure (World Health Organization, 2019). To improve screening for high-risk pregnancies, we set out to identify patterns of maternal hematological changes associated with future pregnancy complications.

METHODS

Using mixed effects models, we established changes in 14 complete blood count (CBC) parameters for 1710 healthy pregnancies and compared them to measurements from 98 pregnancy-induced hypertension, 106 gestational diabetes and 339 postpartum hemorrhage cases.

RESULTS

Results show interindividual variations, but good individual repeatability in CBC values during physiological pregnancies, allowing the identification of specific alterations in women with obstetric complications. For example, in women with uncomplicated pregnancies, haemoglobin count decreases of 0.12 g/L (95% CI -0.16, -0.09) significantly per gestation week (p value <.001). Interestingly, this decrease is three times more pronounced in women who will develop pregnancy-induced hypertension, with an additional decrease of 0.39 g/L (95% CI -0.51, -0.26). We also confirm that obstetric complications and white CBC predict the likelihood of giving birth earlier during pregnancy.

CONCLUSION

We provide a comprehensive description of the associations between haematological changes through pregnancy and three major obstetric complications to support strategies for prevention, early-diagnosis and maternal care.

The association between induction of labour in nulliparous women at term and subsequent spontaneous preterm birth: a retrospective cohort study

OBJECTIVES

To evaluate the rate of subsequent spontaneous preterm birth in patients with previous induction of labour at term compared to women with previous spontaneous labour at term.

METHODS

This was a retrospective cohort study of all women with consecutive births at the Royal Brisbane and Women's Hospital between 2014 and 2018. All nulliparous women with a singleton pregnancy and induction of labour at term or in spontaneous labour at term in the index pregnancy were included. Data was extracted from electronic medical records. The outcome of spontaneous preterm birth in the subsequent pregnancy was compared between patients with previous term induction of labour and in previous term spontaneous labour.

RESULTS

A total of 907 patients with consecutive births met the inclusion criteria; of which 269 (29.7%) had a term induction of labour and 638 (70.3%) had a term spontaneous labour in the index pregnancy. The overall subsequent spontaneous preterm birth rate was 2.3%. Nulliparous women who underwent term induction of labour were less likely to have a subsequent preterm birth compared to nulliparous women in term spontaneous labour (0.74 vs. 2.98%; odds ratio [OR], 0.25; 95% confidence interval, 0.06-1.07; p=0.0496) in the index pregnancy. This however was not significant once adjusted for confounders (adjusted OR, 0.29; p=0.10). Spontaneous preterm birth was associated with a previous spontaneous labour compared to induction of labour between 37 to 37⁺⁶ and 38 to 38⁺⁶ weeks (adjusted OR 0.18 and 0.21; p=0.02 and 0.004 respectively).

CONCLUSIONS

Term induction of labour does not increase the risk of subsequent spontaneous preterm birth compared to spontaneous labour at term in nulliparous women. Further research is needed to validate these findings in a larger cohort of women and to evaluate the effect of elective IOL among low-risk nulliparous women.

Pregnancy anxiety, placental corticotropin-releasing hormone and length of gestation

OBJECTIVE

High pregnancy anxiety is a consistent predictor of earlier labor and delivery. Placental corticotropin-releasing hormone (pCRH) predicts earlier delivery consistently and it has been identified as a biological mediator of the association between pregnancy anxiety and gestational length. However, studies have not examined whether changes in pregnancy anxiety are associated with earlier birth as mediated by changes in pCRH during pregnancy. Accordingly, this study tests whether linear changes in pregnancy anxiety are associated with length of gestation indirectly through nonlinear increases in pCRH over pregnancy.

METHODS

A sample of pregnant women (n=233) completed prenatal assessments in early pregnancy, second trimester, and third trimester that included a 4-item assessment of pregnancy anxiety and collection of blood samples assayed for pCRH using radioimmunoassay. Length of gestation was abstracted from medical records after birth.

RESULTS

Increases in pregnancy anxiety from early pregnancy to third trimester predicted shorted length of gestation, as did nonlinear increases in pCRH over pregnancy. However, there was no evidence of an indirect effect of changes in pregnancy anxiety on length of gestation via changes in pCRH.

CONCLUSIONS

These results indicate that linear changes in pregnancy anxiety and nonlinear changes in pCRH during pregnancy are independent risk factors for shortened gestational length. This study adds to a small but growing body of work on biopsychological processes in pregnancy and length of gestation. Modeling changes in psychological and biological processes during pregnancy could provide more insight into understanding risk for adverse pregnancy outcomes.

Risk of preterm delivery after medically indicated termination of pregnancy with induced vaginal delivery: a case-control study

We investigated whether nonsurgical termination of pregnancy after 14 weeks of gestation increases the risk of preterm delivery in a subsequent pregnancy. We conducted a two-centre retrospective case-control study. Patients who underwent non-surgical termination of pregnancy after 14 weeks of gestation between 2012 and 2015 and who gave birth after 14 weeks of gestation to a live-born singleton infant were included. Control patients were those who gave birth after 37 weeks of gestation (the same month as a case patient) and had a second delivery of a singleton foetus after 14 weeks of gestation. The primary outcome was preterm delivery during the second pregnancy period. We included 151 cases and 302 controls and observed 13 (8.6%) preterm births during the second pregnancy in the case group versus 8 (2.6%) (odds ratio: 3.62; 95% confidence interval: 1.40-8.65, p < .001) in the control group. This result remained significant after multivariate analysis. Impact statementWhat is already known about this topic? Many studies have evaluated the association between first-trimester surgical or non-surgical termination of pregnancy and the risk of preterm birth in the subsequent pregnancy. However, no study has evaluated the association between second- or third-trimester non-surgical termination of pregnancy due to foetal disease and the risk of preterm birth in the subsequent pregnancy. A small number of studies have included a small proportion of patients who previously underwent non-surgical termination of pregnancy after 14 weeks of gestation and later experienced first-trimester termination during their second pregnancy. These studies focussed on the impact of the interpregnancy interval or pharmacological induction of labour on the risk of preterm delivery in the subsequent pregnancy.What did the results of this study add? This is the first study to specifically evaluate the association between second- and third-trimester non-surgical terminations of pregnancy and the risk of preterm birth in the subsequent pregnancy. When compared with term birth, nonsurgical termination of pregnancy was associated with the risk of spontaneous preterm birth and hospitalisation in the neonatal intensive care unit in the subsequent pregnancy.What are the implications of these findings for clinical practice and further research? Further studies are required to confirm our results, but information delivered to patients with a late termination of pregnancy and during their pregnancy follow-up for the subsequent pregnancy could be modified to provide this information.

Demographic Profile, Etiology, and Perinatal Outcome Associated With Preterm Birth in a Tertiary Hospital of Eastern India: A Retrospective Study

Background Preterm birth (PB), defined as birth occurring at less than 37 weeks of gestation, is a leading cause of perinatal mortality and morbidity in the world. Objectives This study aimed to evaluate the socio-demographic characteristics and etiological factors associated with preterm birth and consequent adverse perinatal outcomes retrospectively at a tertiary care hospital.  Methods A single-centre retrospective observational study was conducted in the department of Obstetrics & Gynaecology, Fakir Mohan Medical College & Hospital, Balasore, Odisha, India, from April 2019 to March 2020. Data were retrieved from the antenatal ward admission register, case files, theatre records, and neonatal care unit records and reviewed. Descriptive statistics were used to describe data. Chi-square test and student's t-test were used to find significance of difference between variables. Results The incidence of preterm birth in the study population was 5.52%. The mean gestational age of preterm deliveries was 34.39 ± 1.92 weeks. The bulk of the women hailed from a rural background and belonged to the lower socioeconomic strata. About 47.29% of the women were nulliparous and spontaneous preterm birth was noted in 70.40%. Premature rupture of membranes (PROM), anaemia, intrauterine growth restriction (IUGR), preeclampsia, and eclampsia were the most common adverse pregnancy conditions prevalent in these women. Preterm deliveries comprised 31.21% of all neonatal intensive care unit (NICU) admissions. Respiratory distress syndrome, birth asphyxia, neonatal sepsis, and jaundice were the most common complications. Neonatal death occurred in 51 (9.21%) preterm infants with birth asphyxia being the commonest cause of such deaths. Maternal factors and adverse neonatal outcome variables were compared between the spontaneous and iatrogenic/medically indicated preterm birth groups. Preeclampsia, IUGR, and cesarean section were more significantly associated with the iatrogenic group. Conclusion Our study provides a general overview of the associated etiological factors and perinatal health concerns associated with preterm birth in a rural/semi-urban setting in Eastern India. The findings might provide essential data for taking steps toward the prevention and management of preterm birth from a developing country's perspective.

Exposure to Allergen-Specific Immunotherapy in Pregnancy and Risk of Congenital Malformations and Other Adverse Pregnancy Outcomes

BACKGROUND

Owing to insufficient data, current guidelines recommend against initiating allergen-specific immunotherapy (AIT) during pregnancy but suggest that well-tolerated ongoing immunotherapy may be continued.

OBJECTIVE

To evaluate the safety of AIT in pregnancy, especially the risk for congenital malformations.

METHODS

This nationwide Swedish cohort study identified pregnancies exposed to AIT, both subcutaneous and sublingual, through the Swedish Medical Birth register and the Prescribed Drug Register between 2005 and 2014. Information on congenital malformations in offspring was retrieved from the National Patient Register. Using the personal identity number, we linked data between registers. Using logistic regression, we calculated odds ratios (ORs) with 95% CIs for congenital malformations and other adverse pregnancy outcomes after adjusting for potential confounders.

RESULTS

From 2005 to 2014, we identified 924,790 singleton pregnancies. Among these, 743 pregnancies had been exposed to AIT 3 months before conception up until gestational week 22. Allergen-specific immunotherapy in pregnancy was not linked to congenital malformations (OR = 0.90; 95% CI, 0.63-1.27) or other adverse pregnancy outcomes (preterm birth: OR = 0.98; 95% CI, 0.71-1.35; stillbirth: OR = 0.79; 95% CI, 0.26-2.47; or cesarean delivery: OR = 0.91; 95% CI, 0.76-1.09). Stratification by route of immunotherapy, subcutaneous or sublingual, resulted in similar ORs. Restricting the pregnancy cohort to women with asthma or pulmonary disease, nulliparous women, births in 2012 to 2014, or Swedish-born women yielded similar results.

CONCLUSIONS

This nationwide study found no evidence of congenital malformations or other adverse pregnancy outcomes in women treated with AIT in pregnancy.

Are pre- and early pregnancy lifestyle factors associated with the risk of preterm birth? A secondary cohort analysis of the cluster-randomised GeliS trial

Background

Maternal lifestyle is discussed as a modifiable determinant in the prevention of preterm birth. However, previous research on associations between individual lifestyle factors and preterm birth risk is inconclusive. In this secondary analysis, we investigated the associations between several modifiable antenatal lifestyle factors and the odds of preterm birth.

Methods

This secondary cohort analysis used data from the cluster-randomised controlled “healthy living in pregnancy” (GeliS) trial. Data were collected from early pregnancy to birth with maternity records, validated questionnaires and birth protocols. Women with complete datasets for all covariates were eligible for analysis. Multivariate logistic regression models, adjusted for recognised risk factors, were fitted to determine whether dietary quality, assessed with a healthy eating index (HEI), physical activity (PA) levels and antenatal anxiety/distress influenced the odds of preterm birth. Moreover, the combined association between pre-pregnancy body mass index (BMI) and HEI on the odds of preterm birth was explored. The independent associations of individual dietary components and types of PA on prematurity were assessed by adjusted logistic regression models.

Results

Overall, 1738 women were included in the analysis. A low HEI significantly increased the odds of preterm birth (OR 1.54 (CI 1.04 – 2.30), p = 0.033), while no associations with either low PA levels or antenatal anxiety/distress were observed. BMI significantly interacted with HEI on the association with prematurity (p = 0.036). Energy % from protein and the intake of average portions of vegetables and cereals were significantly negatively associated with the odds of preterm birth. There was no significant evidence of an association between different types of PA and prematurity.

Conclusions

This cohort analysis revealed that low dietary quality in early pregnancy may increase the chance of giving birth prematurely, while healthier dietary choices may help to prevent preterm birth. More research on pre- and early pregnancy modifiable lifestyle factors is warranted.

Trial registration

This trial is registered with the Clinical Trial Registry ClinicalTrials.gov (NCT01958307). Registration date 09 October 2013, retrospectively registered.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12884-022-04513-5.

Frequency and Molecular Characterization of Staphylococcus aureus from Placenta of Mothers with Term and Preterm Deliveries

Globally, prematurity is the leading cause of neonatal mortality (babies in the first four weeks of life) and now the second leading cause of mortality after pneumonia in children under age five. The neonatal gut microbial colonization is crucial in the human life cycle. Placental microbiota transmits from the gut microbiota plays a significant role in association with kinship. Simultaneously, this transition is being made from mother to infant. This comparative study explored the diversity of microbiota associated with term and preterm neonates by evaluating the placental samples. The study found that 16/68 (23.5%) full-term placental samples were positive for S. aureus; on the other hand, 4/16 (25%) preterm placental samples confirmed culture growth for S. aureus. Antimicrobial susceptibility patterns showed that Staphylococcusaureus (S. aureus) isolates from both types of samples were resistant to Ofloxacin, Trimethoprim-sulfamethoxazole, Oxacillin, and Cefoxitin. However, Methicillin-Resistant Staphylococcus aureus (MRSA) detection was 43.75% in full-term and 75% in preterm placental samples. Moreover, two isolates were positive for both mecA and PVL virulent genes, and the rest were positive only for the mecA gene. Interestingly few isolates lacked both characteristic MRSA genes, mecA and PVL. Notably, resistances were more inclined towards preterm samples for antimicrobial susceptibility and MRSA screening. It may be concluded that there is a significant presence of S. aureus in the placenta of mothers with term and preterm deliveries which might be responsible for preterm deliveries. Therefore, judicious use of antibiotics during pregnancies may help prevent preterm births.

Cytokine Patterns in Maternal Serum From First Trimester to Term and Beyond

Pregnancy implies delicate immunological balance between two individuals, with constant changes and adaptions in response to maternal capacity and fetal demands. We performed cytokine profiling of 1149 longitudinal serum samples from 707 pregnant women to map immunological changes from first trimester to term and beyond. The serum levels of 22 cytokines and C-reactive protein (CRP) followed diverse but characteristic trajectories throughout pregnancy, consistent with staged immunological adaptions. Eotaxin showed a particularly robust decrease throughout pregnancy. A strong surge in cytokine levels developed when pregnancies progressed beyond term and the increase was amplified as labor approached. Maternal obesity, smoking and pregnancies with large fetuses showed sustained increase in distinct cytokines throughout pregnancy. Multiparous women had increased cytokine levels in the first trimester compared to nulliparous women with higher cytokine levels in the third trimester. Fetal sex affected first trimester cytokine levels with increased levels in pregnancies with a female fetus. These findings unravel important immunological dynamics of pregnancy, demonstrate how both maternal and fetal factors influence maternal systemic cytokines, and serve as a comprehensive reference for cytokine profiles in normal pregnancies.

Poor Adherence to the WHO Guidelines on Feeding Practices Increases the Risk for Respiratory Infections in Surinamese Preschool Children

Poor feeding practices in infants and young children may lead to malnutrition, which, in turn, is associated with an increased risk of infectious diseases, such as respiratory tract infections (RTIs), a leading cause of under-five mortality. We explored the association between RTIs and the WHO infant and young child feeding (IYCF) indicators: minimum dietary diversity (MDD), minimum meal frequency (MMF), and minimum acceptable diet (MAD), among infants and preschool children in Suriname. A validated pediatric food frequency questionnaire was used and data on RTIs, defined as clinical care for fever with respiratory symptoms, bronchitis, or pneumonia were obtained. Associations between feeding indicators and RTIs were explored using hierarchical logistic regression. Of 763 children aged 10-33 months, 51.7% achieved the MDD, 88.5% the MMF, and 46.5% the MAD. Furthermore, 73% of all children experienced at least one upper and/or lower RTI. Children meeting the MDD and MAD had significantly lower odds on RTIs (OR 0.53; 95%CI: 0.37-0.74, p < 0.001; OR 0.55; 95%CI: 0.39-0.78, p < 0.001, respectively). The covariates parity and household income were independently associated with RTIs. In conclusion, MDD and MAD were associated with (upper) RTIs. Whether these indicators can be used as predictors for increased risk for RTIs should be assessed in future prospective studies.

Incidence, associated risk factors, and the ideal mode of delivery following preterm labour between 24 to 28 weeks of gestation in a low resource setting

BACKGROUND

Preterm labour, between 24 to 28 weeks of gestation, remains prevalent in low resource settings. There is evidence of improved survival after 24 weeks though the ideal mode of delivery remains unclear. There are no clear management protocols to guide patient management. We sought to determine the incidence of preterm labour occurring between 24 to 28 weeks, its associated risk factors and the preferred mode of delivery in a low resource setting with the aim of streamlining patient care.

METHODS

Between February 2020 and September 2020, we prospectively followed 392 women with preterm labour between 24 to 28 weeks of gestation and their newborns from admission to discharge at Kawempe National Referral hospital in Kampala, Uganda. The primary outcome was perinatal mortality associated with the different modes of delivery. Secondary outcomes included neonatal and maternal infections, admission to the Neonatal Special Care Unit (SCU), need for neonatal resuscitation, preterm birth and maternal death. Chi-square test was used to assess the association between perinatal mortality and categorical variables such as parity, mode of delivery, employment status, age, antepartum hemorrhage, digital vaginal examination, and admission to Special Care unit. Multivariate logistic regression was used to assess the association between comparative outcomes of the different modes of delivery and maternal and neonatal risk factors.

RESULTS

The incidence of preterm labour among women who delivered preterm babies between 24 to 28 weeks was 68.9% 95% CI 64.2-73.4). Preterm deliveries between 24 to 28 weeks contributed 20% of the all preterm deliveries and 2.5% of the total hospital deliveries. Preterm labour was independently associated with gravidity (p-value = 0.038), whether labour was medically induced (p-value <0.001), number of digital examinations (p-value <0.001), history of vaginal bleeding prior to onset of labour (p-value < 0.001), whether tocolytics were given (p-value < 0.001), whether an obstetric ultrasound scan was done (p-value <0.001 and number of babies carried (p-value < 0.001). At multivariate analysis; multiple pregnancy OR 15.45 (2.00-119.53), p-value < 0.001, presence of fever prior to admission OR 4.03 (95% CI .23-13.23), p-value = 0.002 and duration of drainage of liquor OR 0.16 (0.03-0.87), p-value = 0.034 were independently associated with preterm labour. The perinatal mortality rate in our study was 778 per 1000 live births. Of the 392 participants, 359 (91.5%), had vaginal delivery, 29 (7.3%) underwent Caesarean delivery and 4 (1%) had assisted vaginal delivery. Caesarean delivery was protective against perinatal mortality compared to vaginal delivery OR = 0.36, 95% CI 0.14-0.82, p-value = 0.017). The other protective factors included receiving antenatal corticosteroids OR = 0.57, 95% CI 0.33-0.98, p-value = 0.040, Doing 3-4 digital exams per day, OR = 0.41, 95% 0.18-0.91, p-value = 0.028) and hospital stay of > 7 days, p value = 0.001. Vaginal delivery was associated with maternal infections, postpartum hemorrhage, and admission to the Special Care Unit.

CONCLUSION

Caesarean delivery is the preferred mode of delivery for preterm deliveries between 24 to 28 weeks of gestation especially when labour is not established in low resource settings. It is associated with lesser adverse pregnancy outcomes when compared to vaginal delivery for remote gestation ages.