Exposure to tobacco smoke and stillbirth: a national prospective cohort study in rural China

Predictive factors and adverse perinatal outcomes associated with maternal smoking status

To identify risk factors for smoking among pregnant women, and adverse perinatal outcomes among pregnant women. A case-control study of singleton full-term pregnant women who gave birth at a university hospital in Jordan in June 2020. Pregnant women were divided into three groups according to their smoking status, active, passive, and non-smokers. They were interviewed using a semi-structured questionnaire that included demographic data, current pregnancy history, and neonatal outcomes. Low-level maternal education, unemployment, secondary antenatal care, and having a smoking husband were identified as risk factors for smoke exposure among pregnant women. The risk for cesarean section was ninefold higher in nulliparous smoking women. Women with low family income, those who did not receive information about the hazards of smoking, unemployed passive smoking women, and multiparty raised the risk of neonatal intensive care unit admission among active smoking women. This risk increased in active and passive women with lower levels of education, and inactive smoking women with low family income by 25 times compared to women with a higher level of education. Smoking is associated with adverse perinatal outcomes. Appropriate preventive strategies should address modifiable risk factors for smoking during pregnancy.

Paternal Nicotine/Ethanol/Caffeine Mixed Exposure Induces Offspring Rat Dysplasia and Its Potential "GC-IGF1" Programming Mechanism

Clinical and animal studies suggest that paternal exposure to adverse environments (bad living habits and chronic stress, etc.) has profound impacts on offspring development; however, the mechanism of paternal disease has not been clarified. In this study, a meta-analysis was first performed to suggest that paternal exposure to nicotine, ethanol, or caffeine is a high-risk factor for adverse pregnancy outcomes. Next, we created a rat model of paternal nicotine/ethanol/caffeine mixed exposure (PME), whereby male Wistar rats were exposed to nicotine (0.1 mg/kg/d), ethanol (0.5 g/kg/d), and caffeine (7.5 mg/kg/d) for 8 weeks continuously, then mated with normal female rats to obtain a fetus (n = 12 for control group, n = 10 for PME group). Then, we analyzed the changes in paternal hypothalamic-pituitary-adrenal (HPA) axis activity, testicular function, pregnancy outcomes, fetal serum metabolic indicators, and multiple organ functions to explore the mechanism from the perspective of chronic stress. Our results demonstrated that PME led to enhanced paternal HPA axis activity, decreased sperm quality, and adverse pregnancy outcomes (stillbirth and absorption, decreased fetal weight and body length, and intrauterine growth retardation), abnormal fetal serum metabolic indicators (corticosterone, glucolipid metabolism, and sex hormones), and fetal multi-organ dysfunction (including hippocampus, adrenal, liver, ossification, and gonads). Furthermore, correlation analysis showed that the increased paternal corticosterone level was closely related to decreased sperm quality, adverse pregnancy outcomes, and abnormal offspring multi-organ function development. Among them, the decreased activity of the glucocorticoid-insulin-like growth factor 1 (GC-IGF1) axis may be the main mechanism of offspring development and multi-organ dysfunction caused by PME. This study explored the impact of common paternal lifestyle in daily life on offspring development, and proposed the GC-IGF1 programming mechanisms of paternal chronic stress-induced offspring dysplasia, which provides a novel insight for exploring the important role of paternal chronic stress in offspring development and guiding a healthy lifestyle for men.

Smoking and Its Consequences on Male and Female Reproductive Health

Smoking contributes to the death of around one in 10 adults worldwide. Specifically, cigarettes are known to contain around 4000 toxins and chemicals that are hazardous in nature. The negative effects of smoking on human health and interest in smoking-related diseases have a long history. Among these concerns are the harmful effects of smoking on reproductive health. Thirteen percent of female infertility is due to smoking. Female smoking can lead to gamete mutagenesis, early loss of reproductive function, and thus advance the time to menopause. It has been also associated with ectopic pregnancy and spontaneous abortion. Even when it comes to assisted reproductive technologies cycles, smokers require more cycles, almost double the number of cycles needed to conceive as non-smokers. Male smoking is shown to be correlated with poorer semen parameters and sperm DNA fragmentation. Not only active smokers but also passive smokers, when excessively exposed to smoking, can have reproductive problems comparable to those seen in smokers. In this book chapter, we will approach the effect of tobacco, especially tobacco smoking, on male and female reproductive health. This aims to take a preventive approach to infertility by discouraging smoking and helping to eliminate exposure to tobacco smoke in both women and men.

Active and Passive Maternal Smoking During Pregnancy and Birth Outcomes: A Study From a Developing Country

Background:

Smoking is one of the modifiable risk factors for adverse maternal and neonatal outcomes and is associated with low birth weight, preterm birth, respiratory, antepartum and intrapartum stillbirth, and perinatal death as well as long-term morbidity in offspring and sudden unexpected infant death. The rate of smoking in low- and middle-income countries is still relevantly high, and Jordan is no exception.

Objective:

To investigate the effect of active and passive smoking during pregnancy on adverse pregnancy outcomes.

Methods:

The case-control study was conducted in Jordan in June 2020. Healthy women with full-term singleton pregnancy (n = 180) were interviewed and stratified into three groups: Group I, active smokers; Group II, passive smokers; and Group III, nonsmokers. The study variables included demographic data, current pregnancy history, cotinine level of mothers and newborns, and perinatal outcomes. Statistical analysis was performed using the application package IBM SPSS 25. Various algorithms of statistical analysis were used depending on the type of distribution of feature and data quality. The threshold for statistical significance was set at p < 0.05.

Results:

Active smokers had significantly lower gestational age at delivery compared to passive and nonsmoking women (p = 0.038 and p = 0.003, respectively). Neonates from active smoking mothers had significantly lower birth weight compared to neonates from passive and nonsmoking women (p = 0.016 and p = 0.019, respectively), significantly lower head and chest circumferences compared to babies from passive smokers (p < 0.001 and p = 0.036, respectively), and significantly lower first-minute Apgar score compared to those from nonsmoking women (p = 0.023). The urine cotinine level was significantly higher in both active and passive smoking women (both p < 0.01), and it was significantly higher in newborns who had been exposed to smoking in utero despite maternal active or passive smoking status (both p < 0.001). There was a weak negative correlation between urine cotinine level and birth weight: r = –0.14 for maternal cotinine level and r = –0.15 for neonate cotinine level.

Conclusions:

The current study illustrated that smoking during pregnancy leads to offspring with reduced birth weight, birth length, and head and chest circumference; reduces delivery gestational age; and lowers the first-minute Apgar score. Our study findings highlight the need for further research issued to smoking effects on perinatal outcomes, the implementation of actions to develop cessation interventions in the preconception period, and an evaluation of useful interventions to enhance a smoking-free environment during pregnancy.

Secondhand Smoke Exposure of Expectant Mothers in China: Factoring in the Role of Culture in Data Collection

Cancer is the leading cause of death worldwide. Tobacco smoking, including secondhand smoking, causes cancer and is responsible for over 22% of global cancer deaths. The adverse impacts of secondhand smoke are more pronounced for expectant mothers, and can deteriorate both mothers’ and infants’ health and well-being. Research suggests that secondhand smoke significantly increases expectant mothers’ risk of miscarriage, cancer, and other chronic disease conditions, and exposes their unborn babies to an increased likelihood of having life-long poor health. In China, a pregnant woman’s family members, such as her husband, parents, or in-laws, are the most likely people to be smoking around her. Due to traditional Chinese cultural practices, even though some expectant mothers understand the harm of secondhand smoke, they may be reluctant to report their family members’ smoking behaviors. Resulting in severe underreporting, this compromises health experts’ ability to understand the severity of the issue. This paper proposes a novel approach to measure secondhand smoke exposure of pregnant women in the Chinese context. The proposed system could act as a stepping stone that inspires creative methods to help researchers more accurately measure secondhand smoking rates of expectant mothers in China. This, in turn, could help health experts better establish cancer control measures for expectant mothers and decrease their cancer risk.