Smoking for two- effects of tobacco consumption on placenta

Pregnancy in women with congenital heart disease: New insights into neonatal risk prediction

BACKGROUND

Advances in managing adult congenital heart disease (ACHD) have led to an increased number of women with CHD reaching childbearing age. This demographic shift underscores the need for improved understanding and prediction of complications during pregnancy in this specific ACHD population. Despite progress in maternal cardiac risk assessment, the prediction of neonatal outcomes for ACHD pregnancies remains underdeveloped. Therefore, the aims of this study are to assess neonatal outcomes in a CHD women population, to identify their predictive factors and to propose a new risk score for predicting neonatal complications.

METHODS

This registry study included all women born between 1975 and 1996 diagnosed with ACHD who underwent at least one cardiology consultation for ACHD in Cliniques Universitaires Saint-Luc. A multivariate analysis was performed to identify predictors of neonatal complications and these were incorporated into a new risk index. Its validity was assessed using bootstrap method. This score was then compared with scores adapted from the ZAHARA and CARPREG studies for offspring events prediction.

RESULTS

Analysis of 491 pregnancies revealed 31.4% of neonatal complications. Four significant predictors of adverse neonatal outcomes were identified: cardiac treatment during pregnancy (OR 14.8, 95%CI [3.4-66]), hypertensive disorders of pregnancy (OR 11.4, 95%CI [3.4-39.0]), smoking during pregnancy (OR 10.6, 95%CI [2.8-40.6]), and pre-pregnancy BMI <18.5 kg/m² (OR 6.5, 95%CI [2.5-16.5]). The risk model demonstrated an AUC of 0.70 (95%CI [0.65-0.75]), which remained stable after bootstrap validation. This model significantly outperformed the scores adapted from ZAHARA and CARPREG data. Based on the regression coefficients, a risk score was subsequently developed comprising five risk categories.

CONCLUSIONS

One third of ACHD pregnancies are complicated by poor neonatal outcome. These complications are determined by four independent factors relating to the cardiac and non-cardiac status of the patients, which have been incorporated into a risk score. Our study is one of the first to propose a predictive risk score of neonatal outcomes in ACHD pregancies, and paves the way for other validation and confirmation studies.

Frontiers in the Etiology and Treatment of Preterm Premature Rupture of Membrane: From Molecular Mechanisms to Innovative Therapeutic Strategies

Preterm premature rupture of membranes (pPROM) poses a significant threat to fetal viability and increases the risk for newborn morbidities. The perinatal period of preterm infants affected by pPROM is often characterized by higher rates of mortality and morbidity, with associated risks of cerebral palsy, developmental delays, compromised immune function, respiratory diseases, and sensory impairments. pPROM is believed to result from a variety of causes, including but not limited to microbially induced infections, stretching of fetal membranes, oxidative stress, inflammatory responses, and age-related changes in the fetal-placental interface. Maternal stress, nutritional deficiencies, and medically induced procedures such as fetoscopy are also considered potential contributing factors to pPROM. This comprehensive review explores the potential etiologies leading to pPROM, delves into the intricate molecular mechanisms through which these etiologies cause membrane ruptures, and provides a concise overview of diagnostic and treatment approaches for pPROM. Based on available therapeutic options, this review proposes and explores the possibilities of utilizing a novel composite hydrogel composed of amniotic membrane particles for repairing ruptured fetal membranes, thereby holding promise for its clinical application.

Construction of prediction model for fetal growth restriction during first trimester in an Asian population

OBJECTIVE

To construct a prediction model for fetal growth restriction (FGR) during the first trimester of pregnancy and evaluate its screening performance.

METHODS

This was a prospective cohort study of singleton pregnancies that underwent routine ultrasound screening at 11 to 13 + 6 weeks at the Affiliated Suzhou Hospital of Nanjing Medical University between January 2019 and April 2022. Basic clinical information, ultrasound indicators and serum biomarkers of pregnant women were collected. Fetal weight assessment was based on the fetal growth curve for the Southern Chinese population. FGR was diagnosed according to Delphi consensus criteria. Least absolute shrinkage and selection operator (lasso) regression was used to select variables for inclusion in the model. Discrimination, calibration and clinical effectiveness of the model were evaluated in training and validation cohorts.

RESULTS

A total of 1188 pregnant women were included, of whom 108 had FGR. Lasso regression identified seven predictive features, including history of maternal hypertension, maternal smoking or passive smoking, gravidity, uterine artery pulsatility index, ductus venosus pulsatility index and multiples of the median values of placental growth factor and soluble fms-like tyrosine kinase-1. The nomogram prediction model constructed from these seven variables accurately predicted FGR, and the area under the receiver-operating-characteristics curve in the validation cohort was 0.82 (95% CI, 0.74-0.90). The calibration curve and Hosmer-Lemeshow test demonstrated good calibration, and the clinical decision curve and clinical impact curve supported its practical value in a clinical setting.

CONCLUSION

The multi-index prediction model for FGR has good predictive value during the first trimester. © 2023 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Environmental tobacco smoke increased risk of gestational diabetes mellitus: A birth cohort study in Sichuan, China

INTRODUCTION

Studies on the relationship between environmental tobacco smoke (ETS) and gestational diabetes mellitus (GDM) are limited. In this study, we aimed to clarify the association between ETS at different trimesters of pregnancy and the risk of GDM among non-smoking pregnant women.

METHODS

A total of 16,893 non-smoking mothers from the Southwest Birth Cohort, China, were included in the final analyses. Exposure and outcome measures included self-reported ETS status at different trimesters of pregnancy and GDM diagnosis. Multivariable logistic regression models were constructed to estimate the association between ETS and GDM.

RESULTS

The prevalence of ETS exposure was 25.7%. Compared with no ETS, ever ETS had an increased risk of GDM, with an adjusted odds ratio (95% confidence intervals) of 1.21 (1.09, 1.33). The association remained consistent at different trimesters of pregnancy ETS exposure. In the last trimester and with continuous ETS exposure, the risk of GDM increased significantly with the increase in the duration of the exposure. The risk of GDM associated with ever ETS during pregnancy significantly increased in mothers over 30 years old and pre-pregnancy overweight (P for interaction <0.05).

CONCLUSIONS

ETS exposure at different trimesters of pregnancy was associated with an increased risk of GDM among non-smoking pregnant women. These findings emphasise the importance of preventing ETS exposure during pregnancy.

Morphological and clinical findings in placentas and newborns with a history of tobacco, alcohol, and other substance abuse during pregnancy

BACKGROUND

Exposure to toxins during pregnancy is the main modifiable behavior that affects the placenta and, consequently, the fetus. In particular, smoking is a recognized risk factor for negative outcomes. Our study pretended to examine gross and microscopic placental features in women who reported exposure to tobacco, alcohol, or other psychoactive substances.

METHODS

In this observational case-control study, we collected 706 placentas to assess precise substance exposure histological-interaction features of in the placenta. We examined gross and microscopic placental features, and then recorded maternal and newborn clinical conditions.

RESULTS

We found that 4.8% of mothers admitted to consumption of some type of (harmful) substance. The most common pre-existing maternal condition was obesity (20.3%); predominant complications included amniotic infection (32.3%), urinary tract infection (14.5%) and hypertensive disorders of pregnancy (14.5%). In newborns, we discovered positive associations as respiratory distress syndrome. Macroscopically, exposed mothers had heavier placentas, more true knots, and single umbilical artery; microscopically, they were more likely to exhibit fetal vascular malperfusion (FVM).

CONCLUSIONS

Until our present study, no research linked umbilical cord defects to toxic substance exposure; our study results do confirm association with adverse outcomes in neonates and alterations in the neuro-cardio-placental circuit through FVM.

IMPLICATIONS

The results are confirming the importance of this modifiable risk factor and how its presence may potentially affect the course of pregnancy, as well as the health of both mother and child.

Smoking during pregnancy and gestational diabetes mellitus: a systematic review and meta-analysis

PURPOSE

To investigate whether maternal cigarette smoking during pregnancy is a risk factor for developing GDM.

METHODS

MEDLINE, Scopus, CENTRAL and Google Scholar databases were searched from inception to December 2022 to identify eligible original articles. A systematic review and meta-analysis (weighted data, random-effects model) were performed. The primary outcome was the development of GDM in pregnant women. The results were expressed as odds ratios (OR) with 95% confidence interval (CI) (inverse variance method). Subgroup analysis was planned according to the maternal smoking status and GDM diagnostic criteria. Statistical heterogeneity was checked with the Chi-squared (Chi2) test and the I2 index was used to quantify it. The studies were evaluated for publication bias.

RESULTS

Thirty-five studies, including 23,849,696 pregnant women, met the inclusion criteria. The pooled OR of smoking during pregnancy compared with non-smoking (never smokers and former smokers) was 1.06 (95% CI 0.95-1.19), p = 0.30; I2 = 90%; Chi2 = 344; df=34; p < 0.001. Subgroup analysis was performed according to the two-step Carpenter-Coustan diagnostic criteria, due to the high heterogeneity among the other applied methods. The pooled OR for the Carpenter-Coustan subgroup was 1.19 (95% CI 0.95-1.49), p = 0.12; I2 = 63%; Chi2 = 27; df=10; p < 0.002. Further subgroup analysis according to maternal smoking status was not performed due to missing data.

CONCLUSION

There is no evidence to support an association between maternal cigarette smoking during pregnancy and the risk for GDM. Universally accepted diagnostic criteria for GDM must be adopted to reduce heterogeneity and clarify the association between smoking and GDM.

Maternal Smoking in the First Trimester and its Consequence on the Early Placenta

Smoking during pregnancy increases the risk of adverse pregnancy outcomes, such as stillbirth and fetal growth restriction. This suggests impaired placental function and restricted nutrient and oxygen supply. Studies investigating placental tissue at the end of pregnancy have revealed increased DNA damage as a potential underlying cause, which is driven by various toxic smoke ingredients and oxidative stress induced by reactive oxygen species (ROS). However, in the first trimester, the placenta develops and differentiates, and many pregnancy pathologies associated with reduced placental function originate here. Therefore, we determined DNA damage in a cohort of first-trimester placental samples of verified smokers and nonsmokers. In fact, we observed an 80% increase in DNA breaks (P < .001) and shortened telomeres by 5.8% (P = .04) in placentas exposed to maternal smoking. Surprisingly, there was a decrease in ROS-mediated DNA damage, ie, 8-oxo-guanidine modifications, in placentas of the smoking group (-41%; P = .021), which paralleled the reduced expression of base excision DNA repair machinery, which restores oxidative DNA damage. Moreover, we observed that the increase in placental oxidant defense machinery expression, which usually occurs at the end of the first trimester in a healthy pregnancy as a result of the full onset of uteroplacental blood flow, was absent in the smoking group. Therefore, in early pregnancy, maternal smoking causes placental DNA damage, contributing to placental malfunction and increased risk of stillbirth and fetal growth restriction in pregnant women. Additionally, reduced ROS-mediated DNA damage along with no increase in antioxidant enzymes suggests a delay in the establishment of physiological uteroplacental blood flow at the end of the first trimester, which may further add to a disturbed placental development and function as a result of smoking in pregnancy.

Associations of circulation levels of cytokines with birthweight, preterm birth, spontaneous miscarriages, and stillbirth: A Mendelian randomization analysis

Background: The association between immune imbalances and adverse pregnancy outcomes has been extensive investigated by observational studies, but remain unclear. Thus, this study aimed to establish the causality of the circulation levels of cytokines on adverse pregnancy outcomes, such as offspring's birthweight (BW), preterm birth (PTB), spontaneous miscarriage (SM), and stillbirth (SB). Methods: Two-sample Mendelian randomization (MR) analysis was employed to investigate potential causal relations between 41 cytokines and pregnancy outcomes on the basis of previously published GWAS datasets. Multivariable MR (MVMR) analysis was implemented to investigate the effect of the composition of cytokine networks on the pregnancy outcomes. Potential risk factors were further estimated to explore the potential mediators. Results: Genetic correlation analysis based on large GWAS data sources revealed that genetically predicted MIP1b (β = -0.027, S.E. = 0.010, p = 0.009) and MCSF (β = -0.024, S.E. = 0.011, p = 0.029) were associated with reduced offspring's BW, MCP1 (OR: 0.90, 95% CI: 0.83-0.97, p = 0.007) was associated with reduced SM risk, SCF (β = -0.014, S.E. = 0.005, p = 0.012) associated with decreased number of SB in MVMR. The univariable MR showed that GROa (OR: 0.92, 95% CI: 0.87-0.97, p = 0.004) was associated with decreased PTB risk. Except for the MCSF-BW association, all above associations surpassed the Bonferroni corrected threshold. The MVMR results revealed that MIF, SDF1a, MIP1b, MCSF and IP10 composed cytokine networks, associated with offspring's BW. Risk factors analysis indicated that the above causal associations might be mediated by smoking behaviors. Conclusion: These findings suggest the causal associations of several cytokines with adverse pregnancy outcomes, which were potentially mediated by smoking and obesity. Some of the results did not been corrected through multiple tests and larger samples verification is required in further studies.

Cigarette smoking during pregnancy and adverse perinatal outcomes: a cross-sectional study over 10 years

BACKGROUND

It has been shown that active exposure to tobacco is associated with adverse pregnancy outcomes including, but not limited to, intrauterine fetal death, reduced fetal weight, and higher risk of preterm birth. We want to investigate these effects in a high-income country.

METHODS

This cross-sectional study examined 20,843 pregnant women who delivered over 10 years at the Maternity Hospital of the Centre Hospitalier Universitaire Vaudois (CHUV) in Lausanne, Switzerland. The objective was to evaluate a dose-response relationship between daily cigarette use during pregnancy and possible adverse perinatal outcomes. The social and clinical characteristics as well as obstetric and neonatal outcomes were compared between the smoking and the non-smoking groups. Adjusted odds ratios (aOR) and trend analyses (p_trend) were calculated.

RESULTS

Nineteen thousand five hundred fifty-four pregnant women met the inclusion criteria and 2,714 (13.9%) of them were smokers. Even after adjusting for confounding factors, smoking during pregnancy was associated with preterm birth, birthweight < 2500 g, intrauterine growth restriction, neonatal respiratory and gastrointestinal diseases, transfer to the neonatal intensive care unit, and neonatal intensive care unit admissions > 7 days. Intrauterine death and neonatal infection were associated with heavy smoking (≥ 20 cigarettes/day). Smoking appeared to be a protective factor for pre-eclampsia and umbilical cord arterial pH below 7.1. A significant trend (p_trend < 0.05) was identified for preterm birth, intrauterine growth restriction, birthweight < 2500 g, umbilical cord arterial pH below 7.1, transfers to our neonatal intensive care unit, and neonatal intensive care unit admissions more than 7 days.

CONCLUSION

Cigarette smoking is associated with several adverse perinatal outcomes of pregnancy with a dose-dependent effect.

Polycyclic aromatic hydrocarbons (PAHs) may explain the paradoxical effects of cigarette use on preeclampsia (PE)

Tobacco smoking and use of snus (smokeless tobacco) are associated with adverse effects on pregnancy and neonatal outcomes. Nicotine is considered a key toxicant involved in effects caused by both smoking and snus, while pyrolysis products including polycyclic aromatic hydrocarbons (PAHs) in cigarette smoke represents the constituents most unequally divided between these two groups of tobacco products. The aim of this review was: i) to compare the impact, in terms of relative effect estimates, of cigarette smoking and use of Swedish snus on pregnancy outcomes using similar non-tobacco user controls, and ii) to examine whether exposure to PAHs from smoking could explain possible differences in impact on pregnancy outcomes. We systematically searched MEDLINE, Embase, PsycInfo, Web of Science and the Cochrane Database of Systematic Reviews up to October 2021 and identified studies reporting risks for adverse pregnancy and neonatal outcomes associated with snus use and with smoking relative to pregnant women with no use of tobacco. Both snus use and smoking were associated with increased risk of stillbirth, preterm birth, and oral cleft malformation, with comparable point estimates. These effects were likely due to comparable nicotine exposure. We also found striking differences. While both smoking and snus increased the risk of having small for gestational age (SGA) infants, risk from maternal smoking was markedly higher as was the reduction in birthweight. In contrast, the risk of preeclampsia (PE) was markedly lower in smokers than in controls, while snus use was associated with a slightly increased risk. We suggest that PAHs acting via AhR may explain the stronger effects of tobacco smoking on SGA and also to the apparent protective effect of cigarette smoking on PE. Possible mechanisms involved include: i) disrupted endocrine control of fetal development as well as placental development and function, and ii) stress adaption and immune suppression in placenta and mother.

Habitual Smoking and Perinatal Outcomes in Japan

Introduction: Smoking during pregnancy has been reported to increase the perinatal risk. We investigated the perinatal outcomes in Japanese pregnant women with habitual smoking at pre-pregnancy and during pregnancy who delivered at our institute in Japan.

Methods: We reviewed the obstetric records of 9280 Japanese women with singleton delivery at ≥22 weeks of gestation at our institute between 2014 and 2019. On admission for delivery, a routine face-to-face interview was conducted by our midwives to ask about smoking during pregnancy.

Results: Of the total 9280 pregnant Japanese women, 532 (5.7%) had smoked before pregnancy. Of these, 272 (51.5%) quitted smoking after being diagnosed with pregnancy, while 258 (49.5%) continued to smoke during pregnancy and were diagnosed with habitual smoking during pregnancy. There was no significant relation between habitual smoking at pre-pregnancy and the perinatal adverse outcomes. However, habitual smoking during pregnancy was associated with the adverse perinatal outcomes such as the increased incidence of placental abruption (adjusted odds ratio [OR] 2.38, p = 0.04) and light-for-gestational-age neonate (adjusted OR 1.72, p = 0.03) on multiple logistic regression analyses.

Conclusion: In this study, smoking was found to be associated with the adverse perinatal outcomes. The current results support the importance of smoking cessation during pregnancy.