Risk factors for preterm birth: a prospective cohort study

Gastroesophageal Reflux Disease and Preterm Birth: Univariate and Multivariate Mendelian Randomization

Background

Observational studies have established a connection between Gastroesophageal reflux disease (GERD) and preterm birth (PTB). Nevertheless, these correlations can be affected by residual confounding or reverse causality, resulting in ambiguity regarding the connection. The objective of this study was to assess the relationship between genetically predicted GERD and PTB.

Methods

Initially, we performed bidirectional univariate Mendelian randomization (UVMR) analysis utilizing publicly accessible genome-wide association studies (GWAS) data. The primary analytical approach employed to determine the causal impact between GERD and PTB is the inverse variance weighted technique (IVW). Subsequently, we utilized multivariate Mendelian randomization (MVMR) to adjust for potential factors that could influence the results, such as body mass index (BMI), maternal smoking around birth, educational attainment, household income, and Townsend deprivation index (TDI). Furthermore, we performed a sequence of comprehensive sensitivity analyses to assess the reliability of our MR findings.

Results

The UVMR analysis results showed a significant correlation between GERD and PTB (odds ratio [OR]: 1.810; 95% confidence interval [CI]: 1.344-2.439; P=9.60E-05) in the IVW model, and the Weighted median method (OR=1.591, 95% CI=1.094-2.315, P=0.015) revealed consistent results. The inverse MR findings suggest no causal link between PTB and the incidence of GERD. In addition, the sensitivity analysis did not detect heterogeneity or horizontal pleiotropy, and the "leave-one-out" examination confirmed that the causal estimation is unlikely to be influenced by the single nucleotide polymorphisms (SNPs) effect. The MVMR analysis demonstrated that the causal association between GERD and PTB still existed after considering BMI, maternal smoking around birth, educational attainment, household income, and TDI (OR=1.921, 95% CI=1.401-2.634, P=5.08E-05).

Conclusion

This study presents evidence indicating that genetically predicted GERD can heighten the risk of PTB. Therefore, it is advisable to perform focused screening for pregnant women with GERD in order to find the initial signs of PTB and promptly apply intervention strategies to extend the duration of pregnancy.

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

Objective

To investigate the association between exposure to atmospheric pollutants and preterm birth in a river valley-type city and its critical exposure windows.

Methods

A retrospective cohort study was used to collect data from the medical records of preterm and full-term deliveries in two hospitals in urban areas of a typical river valley-type city from January 2018 to December 2019. A total of 7,288 cases were included in the study with general information such as pregnancy times, the number of cesarean sections, occupation, season of conception and regularity of the menstrual cycle. And confounding factors affecting preterm birth were inferred using the chi-square test. The effects of exposure to each pollutant, including particulate matter 2.5 (PM2.5), particulate matter 10 (PM10), nitrogen dioxide (NO2), sulfur dioxide (SO2), carbon monoxide (CO) and ozone (O3), during pregnancy on preterm birth and the main exposure windows were explored by establishing a logistic regression model with pollutants introduced as continuous variables.

Results

Maternal age, pregnancy times, number of births, number of cesarean sections, season of conception, complications diseases, comorbidities diseases, hypertension disorder of pregnancy and neonatal low birth weight of the newborn were significantly different between preterm and term pregnant women. Logistic regression analysis after adjusting for the above confounders showed that the risk of preterm birth increases by 0.9, 0.6, 2.4% in T2 and by 1.0, 0.9, 2.5% in T3 for each 10 μg/m3 increase in PM2.5, PM10, NO2 concentrations, respectively. The risk of preterm birth increases by 4.3% in T2 for each 10 μg/m3 increase in SO2 concentrations. The risk of preterm birth increases by 123.5% in T2 and increases by 188.5% in T3 for each 10 mg/m3 increase in CO concentrations.

Conclusion

Maternal exposure to PM2.5, PM10, NO2, CO was associated with increased risk on preterm birth in mid-pregnancy (T2) and late pregnancy (T3), SO2 exposure was associated with increased risk on preterm birth in mid-pregnancy (T2).

Asthma and risk of adverse pregnancy outcomes: A Mendelian randomization study

Background

Multiple empirical investigations have indicated a connection between asthma and adverse pregnancy outcomes (APOs). Nevertheless, the effects of asthma on APOs remain uncertain.

Methods

We performed bi-directional Univariable Mendelian randomization (UVMR) analyses using combined information obtained from genome-wide association studies (GWAS) data that is publicly accessible. The principal approach used to analyze the causal association between asthma or age when diagnosed and APOs was the inverse variance weighted (IVW) method. The two types of data regarding exposure originate from the IEU Open GWAS project, which includes 56,167 and 47,222 European asthma patients, respectively. The data of four APOs were acquired via the GWAS dataset of the FinnGen collaboration. In addition, we implemented multivariable Mendelian randomization (MVMR), controlling for confounding factors such as smoking status, frequent drinking, body mass index (BMI), and live birth quantity. Furthermore, we executed several meticulous sensitivity studies to ascertain the reliability of our MR results.

Results

Following the implementation of the Bonferroni adjustment, the UVMR assessment revealed that in the IVW model, asthma was significantly linked to an elevated risk of spontaneous abortion (SA) (odds ratio [OR]: 1.115; 95 % confidence interval [CI]: 1.031-1.206; P = 0.006) and gestational diabetes mellitus (GDM) (OR: 1.125; 95 % CI: 1.037-1.220; P = 0.005). However, there was no causal correlation between asthma and preterm birth (PTB) (OR: 0.979; 95 % CI: 0.897-1.068; P = 0.629) or preeclampsia (PE) (OR: 1.059; 95 % CI: 0.951-1.179; P = 0.297). After adjusting for confounding factors, including smoking status, frequent drinking, BMI, and live birth quantity, the MVMR analysis shows a statistically significant causal relationship between asthma and SA or GDM. Furthermore, our investigation's findings did not reveal a substantial correlation between the age of asthma onset based on genetics and the likelihood of SA or GDM. The inverse MR outcomes indicate a lack of causal connection linking APOs to the incidence of asthma. The validity of these findings were verified by sensitivity analyses.

Conclusions

The evidence provided by this study proves that genetically determined asthma is linked to a higher likelihood of SA and GDM. Further research is required to examine potential pathways. However, no conclusive evidence has been found to support the increased risk of SA and GDM in early asthma diagnosis or the interaction between asthma and PTB or PE, indicating that confounding factors may affect the results of previous observational studies.

Changes in Gut Microbiota at 1-60 Days in 92 Preterm Infants in a Neonatal Intensive Care Unit Using 16S rRNA Gene Sequencing

BACKGROUND Neonatal gut diversity is influenced by birth conditions and probiotic/antibiotic use. The gut microbiota affects brain development, immunity, and risk of diseases. Preterm infants, especially in neonatal intensive care units (NICUs), have different gut flora from full-term infants, suggesting in utero microbial colonization. This study examined gut microbiota changes in 92 NICU preterm infants in China. MATERIAL AND METHODS We collected data on 92 preterm infants admitted to the NICU immediately after birth, and fecal samples were collected on days 1, 3, 7, 14, 21, 28, and 60. We analyzed changes in intestinal bacteria through 16S rRNA sequencing, predicted the change in gut microbiota function over time, and compared the effects of main feeding modality on the intestinal bacteria of preterm infants. RESULTS At the phylum level, the top 5 phyla in total accounted for 99.69% of the abundance, in decreasing order of abundance: Proteobacteria, Firmicutes, Actinobacteria, Tenericutes, and Bacteroidetes. At the genus level, the top 10 genera in terms of abundance accounted for a total of 90.90%, in decreasing order of abundance: Pseudomonas, Staphylococcus, Klebsiella, Escherichia-Shigella, unclassified Enterobacteriaceae, Staphylococcus, Clostridium-sensu-stricto-1, Streptococcus, Sphingomonas, and Ureaplasma. The abundance of Proteobacteria and Pseudomonas showed a decreasing trend at first, reached a minimum at day 14, and then an increasing trend, while the opposite trend was observed for Firmicutes. The metabolic function of the bacterial community changed greatly at different time points. The abundance of Proteobacteria at the phylum level and Streptococcus at the genus level in formula-fed infants were significantly higher than in breast-fed infants. CONCLUSIONS Between 1 and 60 days, the gut microbiome in preterm infants in the NICU changed with changes in feeding patterns, with the main gut bacteria being from the phyla, Proteobacteria, and Pseudomonas.

The Outcome of Pregnancy Among Tobacco Users in Tertiary Care Hospital of Chhattisgarh Province of India

BACKGROUND

Tobacco use is responsible for numerous adverse pregnancy outcomes for females and their infants. The aim of this study was to explore the adverse outcome of tobacco use among pregnant females.

METHOD

 A cross-sectional study was conducted on 1250 females in the third trimester of pregnancy from April to June 2022, which were exposed to tobacco use in the form of gudaku, tobacco chewing, gutka, or smoking. Complications and outcomes during and after pregnancy were recorded based on self-administered questionnaires. Statistical analysis was performed using the Statistical Package for Social Sciences (SPSS) (IBM SPSS Statistics, Armonk, NY) software version 20.0 for categorical data, frequencies (n) and percentages (%) were calculated, and the chi-square test was used for determining intergroup differences.

RESULTS

 Out of 1250 females, tobacco exposure was present among 429 (34.3%), and 821 (65.7%) had no tobacco exposure. Of 429, 36.10% of females complained about complications such as abortion (1.60%), antepartum hemorrhage (0.90%), congenital anomaly (0.20%), infertility (1.20%), intrauterine fetal death (IUFD) (0.50%), intrauterine growth restriction (IUGR) (0.90%), oligohydramnios (OLIGO) (3.30%), preterm labor (18.40%), premature rupture of membrane (6.30%), and anemia (2.80%), which were slightly higher than the females with no tobacco exposure. In tobacco users, obstructive complications were found to be significant with a p value of 0.0036.

CONCLUSION

Our study concluded that tobacco use could have an adverse effect on their fetus and infants, as well as the pregnant females themselves. Policymakers need to ensure effective strategies that pregnant females, their partners, and close relatives need to have enough knowledge to avoid potential risks.

The Outcome- or Cost-Effectiveness Analysis of LUS-Based Care or CXR-Based Care of Neonatal Lung Diseases: The Clinical Practice Evidence from a Level Ⅲ NICU in China

OBJECTIVE

To compare the effect of managing neonatal lung disease with lung ultrasound (LUS) or chest X-ray (CXR) monitoring on health outcomes and cost-effectiveness.

METHODS

The data obtained from the NICU of the Beijing Chaoyang District Maternal and Child Healthcare Hospital were used as the study group, as LUS has completely replaced CXR in managing newborn lung disease in the hospital for the past 5 years. The primary outcomes of this study were the misdiagnosis rate of respiratory distress syndrome (RDS), the using status of mechanical ventilation, the incidence rate of bronchopulmonary dysplasia (BPD) and the survival rate in hospitalized infants. The secondary outcomes included the use pulmonary surfactant (PS), and the mortality rate of severe diseases (such as pneumothorax, pulmonary hemorrhage and RDS, etc.).

RESULTS

Managing neonatal lung disease with LUS monitoring may enable the following effects: The frequency of ventilator use reducing by 40.2%; the duration of mechanical ventilation reducing by 67.5%; and the frequency of ventilator weaning failure being totally avoided. A misdiagnosis rate of 30% for RDS was also avoided. The dosage of PS was significantly reduced by 50% to 75%. No BPD occurred in the LUS-based care group for 5 years. The fatality rates of RDS, pneumothorax and pulmonary hemorrhage decreased by 100%. The poor prognosis rate of VLBW infants decreased by 85%, and the total mortality rate of hospitalized infants decreased by 90%. Therefore, the cost of LUS-based care was inevitably saved.

CONCLUSIONS

Diagnosing and managing neonatal lung diseases with LUS monitoring have significant benefits, and this technology should be widely promoted and applied around the world.

Prevalence of preterm birth and risk factors associated with it at different gestational ages: A multicenter retrospective survey in China

OBJECTIVES

To investigate the prevalence of preterm birth (PTB) and the risk factors for different gestational age subgroups of preterm birth in China.

METHODS

We carried out a descriptive cross-sectional study encompassing all singleton live births (24⁺⁰ to 41⁺⁶ weeks) with completed data in 23 provinces in China from 2010 to 2017 during investigation period. We compared both the preterm group (24⁺⁰ to 36⁺⁶ weeks) and preterm subgroups (<32 weeks, 32⁺⁰ to 33⁺⁶ weeks, and 34⁺⁰ t0 36⁺⁶ weeks) with the term group (37⁺⁰ to 41⁺⁶ weeks). We collected information on maternal and fetal characteristics from medical records. Logistic regression was use.

RESULTS

The prevalence of PTB was 7.4% (15,833/215,254) in singleton births. After adjusting for maternal age, parity, and potential risk factors in univariate analysis, the high-risk factors for PTB at <32 weeks were placental abruption (aOR=41.52; 95% CI, 25.89-66.58), placenta previa (aOR=40.04; 95% CI, 32.00-50.09), chorioamnionitis (aOR=11.06; 95% CI, 8.738-14.02), and hypertension disorders in pregnancy (HDP) (aOR=3.564; 95% CI, 2.930-4.335). Intrahepatic cholestasis of pregnancy (ICP) was significantly associated with PTB at 34-36 weeks (aOR=5.763; 95% CI, 5.049-6.577), particularly with spontaneous PTB (aOR=10.04; 95% CI, 8.79-11.47). Gestational diabetes mellitus (GDM) was significantly associated with PTB at 34-36 weeks only (aOR=1.156; 95% CI, 1.054-1.267).

CONCLUSION

Placental abruption, placenta previa, chorioamnionitis, and HDP were more predictive of early PTB; GDM and ICP were more predictive of late PTB.