A quantitative study on the effects of maternal smoking on placental morphology and cadmium concentration

Low levels of nicotine and cotinine but not benzo[a]pyrene induce human trophoblast cell proliferation

E-cigarettes use constitutes a source of thirdhand nicotine exposure. The increasing use of electronic cigarettes in homes and public places increases the risk of exposure of pregnant women to thirdhand nicotine. The effects of exposure of pregnant women to very low levels of nicotine have not been studied in humans but detrimental in experimental animals. The objective of this study is to investigate the effect of nanomolar concentrations of nicotine and its metabolite cotinine on the proliferation of JEG-3, a human trophoblast cell line. We also studied the proliferative effect of nanomolar concentrations of benzo[a]pyrene (B[a]P), a polycyclic hydrocarbon in tobacco smoke, for comparison. We treated JEG-3 cells in culture with nanomolar concentrations of nicotine, cotinine, and B[a]P. Their effect on cell proliferation was determined, relative to untreated cells, by MTT assay. Western blotting was used to assess the mitogenic signaling pathways affected by nicotine and cotinine. In contrast to the inhibitory effects reported with higher concentrations, we showed that nanomolar concentrations of nicotine and cotinine resulted in significant JEG-3 cell proliferation and a rapid but transient increase in levels of phosphorylated ERK and AKT, but not STAT3. Biphasic, non-monotonic effect on cell growth is characteristic of endocrine disruptive chemicals like nicotine. The mitogenic effects of nicotine and cotinine potentially contribute to increased villous epithelial thickness, seen in placentas of some smoking mothers. This increases the diffusion distance for oxygen and nutrients between mother and fetus, contributing to intrauterine growth restriction in infants of smoking mothers.

Documento de consenso sobre tabaquismo y riesgo vascular

Consensus statement on smoking and vascular risk About 22% of the Spanish population are daily smokers. Men are more likely to smoke than women. In Spain, women between 15-25 years of age smoke as much or more than men. Every smoker should be assessed for: physical dependence on nicotine (Fagerström test), social and psychological dependence (Glover Nilsson test), level of motivation to quit (Richmond test), probability of therapy success (Henri-Mondor and Michael-Fiore tests), and stage of behavioral change development (Prochaska and DiClementi). Advice on smoking cessation is highly cost-effective and should always be provided. Smoking is an enhancer of cardiovascular risk because it acts as a pathogen agent in the development of arteriosclerosis and is associated with ischemic heart disease, stroke, and peripheral artery disease. Smoking increases the risk of chronic lung diseases (COPD) and is related to cancers of the lung, female genitalia, larynx, oropharynx, bladder, mouth, esophagus, liver and biliary tract, and stomach, among others. Combined oral contraceptives should be avoided in women smokers older than 35 years of age due to the risk of thromboembolism. In smoking cessation, the involvement of physicians, nurses, psychologists, etc. is important, and their multidisciplinary collaboration is needed. Effective pharmacological treatments for smoking cessation are available. Combined treatments are recommended when smoker's dependence is high. For individuals who are unable to quit smoking, a strategy based on tobacco damage management with a total switch to smokeless products could be a less dangerous alternative for their health than continuing to smoke.

Maternal Smoking During Pregnancy and Offspring's Risk for Bone Fracture in Childhood and Adolescence

Conditions during gestation, such as maternal smoking, may affect offspring's bone structure. This could increase the offspring's risk of bone fractures during childhood. In this study, we aimed to assess the association between prenatal exposure to maternal smoking and childhood bone fracture risk. We used a register-based birth cohort that included all children born in Finland between January 1987 and September 1990. After exclusions, the final study population consisted of 220,699 persons. Using a unique national identification number, we linked the cohort data to the fracture diagnosis in specialty care and covariate data using the Medical Birth Register (MBR), Statistics Finland and Care Register for Health Care (CRHC). The fractures were analyzed in three groups: all fractures, non-high-energy fractures, and high-energy fractures. The analyses were adjusted for sex, parity, child's year of birth, mother's age at childbirth, mother's and father's educational level, and mother's fracture status. We tested the association in three age groups: <1 year, 1-<5 years, and 5-<15 years using Cox and (recurrent fractures) Poisson regression. A total of 18,857 (8.5%) persons had at least one bone fracture diagnosis before the age of 15 years. In the age group 5-<15 years, maternal smoking during pregnancy was associated with higher fracture risk in all of the studied fracture groups: hazard ratio (HR) = 1.12 (95% confidence interval [CI] 1.06-1.17) in all fractures, 1.13 (95% CI 1.07-1.19) in non-high-energy, and 1.15 (95% CI 1.00-1.32) in high-energy fractures. There were no significant associations in other age groups in any of the fracture groups. No statistically significant association between maternal smoking during pregnancy and offspring's risk of recurrent fractures was found. In conclusion, 5- to 15-year-olds whose mothers have smoked during pregnancy have an increased risk of bone fractures treated in specialty care. © 2023 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).

Cadmium reduces growth of male fetuses by impairing development of the placental vasculature and reducing expression of nutrient transporters

In utero exposure to the toxic metal cadmium (Cd) alters fetoplacental growth in rodents and has been inversely associated with birth weight and infant size in some birth cohorts. Moreover, studies suggest that Cd may have differential effects on growth and development according to offspring sex. The purpose of the current study was to evaluate changes in male and female fetoplacental development following a single injection of saline (5 ml/kg ip) or cadmium chloride (CdCl2, 2.5, 5 mg/kg, ip) on gestational day (GD) 9. By GD18, no changes in fetal or placental weights were observed after treatment with 2.5 mg/kg CdCl2. By comparison, the weight and length of male fetuses and their placentas were reduced following treatment with 5 mg/kg CdCl2 whereas no change was observed in females. In addition, the area of maternal and fetal blood vessels as well as the expression of the glucose transporters, Glut1 and Glut3, and the endothelial marker, CD34, were reduced in the placentas of CdCl2-treated male offspring compared to females. Interestingly, the placentas of females accumulated 80% more Cd than males after CdCl2 (5 mg/kg) administration. Female placentas also had higher concentrations of zinc and the zinc transporter Znt1 compared to males which may explain the limited changes in fetal growth observed following CdCl2 treatment. Taken together, disruption of vasculature development and reduced expression of glucose transporters in the placenta provide potential mechanisms underlying reduced fetal growth in male offspring despite the greater accumulation of Cd in female placentas.

Killing two birds with one stone: Pregnancy is a sensitive window for endocrine effects on both the mother and the fetus

Pregnancy is a complex process requiring tremendous physiological changes in the mother in order to fulfill the needs of the growing fetus, and to give birth, expel the placenta and nurse the newborn. These physiological modifications are accompanied with psychological changes, as well as with variations in habits and behaviors. As a result, this period of life is considered as a sensitive window as impaired functional and physiological changes in the mother can have short- and long-term impacts on her health. In addition, dysregulation of the placenta and of mechanisms governing placentation have been linked to chronic diseases later-on in life for the fetus, in a concept known as the Developmental Origin of Health and Diseases (DOHaD). This concept stipulates that any change in the environment during the pre-conception and perinatal (in utero life and neonatal) period to puberty, can be "imprinted" in the organism, thereby impacting the health and risk of chronic diseases later in life. Pregnancy is a succession of events that is regulated, in large part, by hormones and growth factors. Therefore, small changes in hormonal balance can have important effects on both the mother and the developing fetus. An increasing number of studies demonstrate that exposure to endocrine disrupting compounds (EDCs) affect both the mother and the fetus giving rise to growing concerns surrounding these exposures. This review will give an overview of changes that happen during pregnancy with respect to the mother, the placenta, and the fetus, and of the current literature regarding the effects of EDCs during this specific sensitive window of exposure.

Increased expression of apoptotic markers in human full-term placenta after exposure to elevated environmental cadmium levels during pregnancy

Cadmium (Cd), a toxic heavy metal, produces various forms of environmental contaminations and health problems in human. In this study, we aimed to examine the localization of several apoptotic markers in human placentas from pregnant women who were environmentally exposed to Cd. Twelve pregnant women participated in this analysis and they were divided into 2 groups according to their living areas: high-Cd (H-Cd) and low-Cd (L-Cd) groups. After delivery, the placentas were immediately harvested, and the placental width, length, and weight were measured. The placental Cd concentration was determined by using ICP-MS. The expression of three apoptotic markers, cleaved caspase-3, cleaved lamin A/C, and TUNEL, was examined in immunohistochemistry. In results, the placental Cd concentration in the H-Cd group was higher than that in the L-Cd group. In contrast, a significant decrease in the BW (birth weight):PW (placenta weight) ratio representing the placental nutrient transport function was found in the H-Cd group, and an inverse correlation between placental Cd concentration and BW:PW ratio was demonstrated. Additionally, significant elevations in the expression of cleaved caspase-3, cleaved lamin A/C proteins, and TUNEL were shown in the H-Cd placenta. Moreover, positive correlations were found between the placental Cd concentration and the expression of cleaved caspase-3 and TUNEL. Collectively, our findings suggest that the exposure of pregnant women to environmental Cd might induce Cd to be transferred to the body and then accumulated in the placenta, resulting in disturbance of the placental function and eventual apoptosis.

Smoking for two- effects of tobacco consumption on placenta

Tobacco smoking is an important public health issue recognized by the world health organization as one of the most serious, preventable risk factors for developing a series of pregnancy pathologies. Maternal smoking is positively associated with intrauterine growth restriction (IUGR) and gestational diabetes (GDM), but negatively associated with preeclampsia (PE). In this review, we examine epidemiological, clinical and laboratory studies of smoking effects on immunoregulation during pregnancy, trophoblast function, and placental vasculature development and metabolism. We aim to identify effects of tobacco smoke components on specific placental compartments or cells, which may contribute to the understanding of the influences of maternal smoking on placenta function in normal and pathological pregnancies. Data corroborates that in any trimester, smoking is unsafe for pregnancy and that its detrimental effects outweigh questionable benefits. The effects of maternal smoking on the maternal immune regulation throughout pregnancy and the impact of different tobacco products on fetal growth have not yet been fully understood. Smoking cessation rather than treatment with replacement therapies is recommended for future mothers because also single components of tobacco and its smoke may have detrimental effects on placental function.

Praegnatio Perturbatio-Impact of Endocrine-Disrupting Chemicals

The burden of adverse pregnancy outcomes such as preterm birth and low birth weight is considerable across the world. Several risk factors for adverse pregnancy outcomes have been identified. One risk factor for adverse pregnancy outcomes receiving considerable attention in recent years is gestational exposure to endocrine-disrupting chemicals (EDCs). Humans are exposed to a multitude of environmental chemicals with known endocrine-disrupting properties, and evidence suggests exposure to these EDCs have the potential to disrupt the maternal-fetal environment culminating in adverse pregnancy and birth outcomes. This review addresses the impact of maternal and fetal exposure to environmental EDCs of natural and man-made chemicals in disrupting the maternal-fetal milieu in human leading to adverse pregnancy and birth outcomes-a risk factor for adult-onset noncommunicable diseases, the role lifestyle and environmental factors play in mitigating or amplifying the effects of EDCs, the underlying mechanisms and mediators involved, and the research directions on which to focus future investigations to help alleviate the adverse effects of EDC exposure.

Outcomes of pregnancies diagnosed with circumvallate placenta, and use of uterine artery pulsatility index and maternal serum alpha-fetoprotein for prediction of adverse outcomes

OBJECTIVES

To evaluate the outcomes, and predictive value of uterine artery pulsatility index (UtA-PI) and second-trimester maternal serum alpha-fetoprotein (MSAFP) for adverse obstetric outcomes in cases with morphologically confirmed circumvallate placenta by comparison with normal pregnancies.

STUDY DESIGN

This prospective study was conducted in a tertiary referral hospital between January 2017 and December 2019. During the study period, 77 patients with a circumvallate placenta and 77 patients without any placental or feto-maternal diseases or abnormalities were evaluated. The final diagnosis was made based on macroscopic examination of the placenta soon after birth. Demographic characteristics, MSAFP, obstetric complications, haemoglobin after delivery, gestational week of birth, fetal sex, 1- and 5-min Apgar scores, postnatal complications and type of delivery were retrieved from hospital records. Bilateral mean transabdominal UtA-PI and MSAFP were evaluated for the prediction of adverse outcomes. SPSS Version 21.0 for Windows was used for statistical analysis, and receiver operating characteristic (ROC) curves were used for the prediction model of adverse outcomes.

RESULTS

Smoking rate, MSAFP, preterm birth and intrauterine growth restriction (IUGR) were higher in the patients with a circumvallate placenta (p = 0.005, 0.00, 0.025 and 0.027, respectively). The cut-off value of MSAFP was 1.41 (0.60-3.32) and the cut-off value of UtA-PI was 1.2 using the ROC curves, and had sensitivity of 73.7 % and specificity of 71.9 %, and sensitivity of 73.7 % and specificity of 76.3 %, respectively (p < 0.05).

CONCLUSIONS

Circumvallate placenta was associated with a higher rate of IUGR, preterm birth and bleeding at the time of delivery. In patients with a circumvallate placenta, UtA-PI and MSAFP may be valuable as predictors of IUGR.

Evaluate the exposure of toxic metals via drinking water and smoking nonbranded cigarette in malnourished women by modified single/two-step cloud point extraction

Presently, the exposure of heavy metals (cadmium and lead) was determined in biological sample (serum) of women (pregnant and nonpregnant) who belong to low socioeconomic group (malnutrition). The cadmium (Cd) and lead (Pb) were determined in drinking water and locally produced cigarette (bidi), smoking by women of childbearing age. The preconcentration of heavy metals in serum, water, and tobacco of bidi were carried out by cloud point extraction at single and two-step methods before determination by atomic absorption spectrometry with flame mode. The Cd and Pb in the water- and acid-digested serum and tobacco samples were treated with a complexing reagent 1-(2-pyridylazo)-2-naphthol (PAN). The hydrophobic complex of Cd and Pb was entrapped in Triton X-114. For the first step, the entrapped analytes in Triton X-114 was diluted with alcoholic acid (0.2 mol/L of HNO₃) and subjected to FAAS, whereas for the second step of CPE, the surfactant-rich analyte was subjected to the second round of enrichment method. Lastly, the analyte was back-extracted in acidic solution (0.2 mol/L) and analyzed by FAAS. The all significant variable was optimized for optimal recovery of Cd and Pb. The recommended single/two-step cloud point extraction method was validated by simultaneously evaluated matrices matched certified reference materials of water, serum, and tobacco. The resulted data indicated that the groundwater samples contained elevated concentrations of Cd and Pb than recommended values for drinking water by WHO, while the contents of Cd and Pb were observed about two-fold higher in nonbranded cigarette (bidi) than branded cigarette. It was observed that there were about 3 to 4 times higher concentrations of both toxic metals in blood serum of smoker malnourished women group than in referent nonsmoker women. Graphical abstract.

The impact of periconceptional maternal lifestyle on clinical features and biomarkers of placental development and function: a systematic review

BACKGROUND

Worldwide, placenta-related complications contribute to adverse pregnancy outcomes, such as pre-eclampsia, fetal growth restriction and preterm birth, with implications for the future health of mothers and offspring. The placenta develops in the periconception period and forms the interface between mother and embryo/fetus. An unhealthy periconceptional maternal lifestyle, such as smoking, alcohol and under- and over-nutrition, can detrimentally influence placental development and function.

OBJECTIVE AND RATIONALE

The impact of maternal lifestyle on placental health is largely unknown. Therefore, we aim to summarize the evidence of the impact of periconceptional maternal lifestyle on clinical features and biomarkers of placental development and function throughout pregnancy.

SEARCH METHODS

A comprehensive search in Medline, Embase, Pubmed, The Cochrane Library Web of Science and Google Scholar was conducted. The search strategy included keywords related to the maternal lifestyle, smoking, alcohol, caffeine, nutrition (including folic acid supplement intake) and body weight. For placental markers throughout pregnancy, keywords related to ultrasound imaging, serum biomarkers and histological characteristics were used. We included randomized controlled trials and observational studies published between January 2000 and March 2017 and restricted the analysis to singleton pregnancies and maternal periconceptional lifestyle. Methodological quality was scored using the ErasmusAGE tool. A protocol of this systematic review has been registered in PROSPERO International prospective register of systematic reviews (PROSPERO 2016:CRD42016045596).

OUTCOMES

Of 2593 unique citations found, 82 studies were included. The median quality score was 5 (range: 0-10). The findings revealed that maternal smoking was associated with lower first-trimester placental vascularization flow indices, higher second- and third-trimester resistance of the uterine and umbilical arteries and lower resistance of the middle cerebral artery. Although a negative impact of smoking on placental weight was expected, this was less clear. Alcohol use was associated with a lower placental weight. One study described higher second- and third-trimester placental growth factor (PlGF) levels after periconceptional alcohol use. None of the studies looked at caffeine intake. Adequate nutrition in the first trimester, periconceptional folic acid supplement intake and strong adherence to a Mediterranean diet, were all associated with a lower resistance of the uterine and umbilical arteries in the second and third trimester. A low caloric intake resulted in a lower placental weight, length, breadth, thickness, area and volume. Higher maternal body weight was associated with a larger placenta measured by ultrasound in the second and third trimester of pregnancy or weighed at birth. In addition, higher maternal body weight was associated with decreased PlGF-levels.

WIDER IMPLICATIONS

Evidence of the impact of periconceptional maternal lifestyle on placental health was demonstrated. However, due to poorly defined lifestyle exposures and time windows of investigation, unstandardized measurements of placenta-related outcomes and small sample sizes of the included studies, a cautious interpretation of the effect estimates is indicated. We suggest that future research should focus more on physiological consequences of unhealthy lifestyle during the critical periconception window. Moreover, we foresee that new evidence will support the development of lifestyle interventions to improve the health of mothers and their offspring from the earliest moment in life.

Maternal smoking during pregnancy and fractures in offspring: national register based sibling comparison study

OBJECTIVE

To study the impact of maternal smoking during pregnancy on fractures in offspring during different developmental stages of life.

DESIGN

National register based birth cohort study with a sibling comparison design.

SETTING

Sweden.

PARTICIPANTS

1 680 307 people born in Sweden between 1983 and 2000 to women who smoked (n=377 367, 22.5%) and did not smoke (n=1 302 940) in early pregnancy. Follow-up was until 31 December 2014.

MAIN OUTCOME MEASURE

Fractures by attained age up to 32 years.

RESULTS

During a median follow-up of 21.1 years, 377 970 fractures were observed (the overall incidence rate for fracture standardised by calendar year of birth was 11.8 per 1000 person years). The association between maternal smoking during pregnancy and risk of fracture in offspring differed by attained age. Maternal smoking was associated with a higher rate of fractures in offspring before 1 year of age in the entire cohort (birth year standardised fracture rates in those exposed and unexposed to maternal smoking were 1.59 and 1.28 per 1000 person years, respectively). After adjustment for potential confounders the hazard ratio for maternal smoking compared with no smoking was 1.27 (95% confidence interval 1.12 to 1.45). This association followed a dose dependent pattern (compared with no smoking, hazard ratios for 1-9 cigarettes/day and ≥10 cigarettes/day were 1.20 (95% confidence interval 1.03 to 1.39) and 1.41 (1.18 to 1.69), respectively) and persisted in within-sibship comparisons although with wider confidence intervals (compared with no smoking, 1.58 (1.01 to 2.46)). Maternal smoking during pregnancy was also associated with an increased fracture incidence in offspring from age 5 to 32 years in whole cohort analyses, but these associations did not follow a dose dependent gradient. In within-sibship analyses, which controls for confounding by measured and unmeasured shared familial factors, corresponding point estimates were all close to null. Maternal smoking was not associated with risk of fracture in offspring between the ages of 1 and 5 years in any of the models.

CONCLUSION

Prenatal exposure to maternal smoking is associated with an increased rate of fracture during the first year of life but does not seem to have a long lasting biological influence on fractures later in childhood and up to early adulthood.

Effects of maternal smoking on human placental vascularization: A systematic review

The abnormal development of placental vascularization leads to placental insufficiency, which further reduces the nutrient and trace exchange between maternal circulation and fetal circulation. These changes cause maternal and fetal complications. The objective of our systematic review was to explore the effects of maternal smoking on placental vascularization. The eligibility criteria were: articles with experimental, quasi-experimental or observational design, performed on human subjects, that study the association, correlation or causation between maternal smoking and changes in placental vascular network. A total of 33 full-text papers were assessed for eligibility, resulting in 12 original articles that were included in the systematic review. Doppler studies confirm reductions in blood flow velocity waveforms and increase in RI in the uterine, umbilical and fetal middle cerebral arteries. These findings are confirmed by morphometric measurements of fetal capillaries in villi that were shown to be smaller in smoke exposure groups.

Drp1 and RB interaction to mediate mitochondria-dependent necroptosis induced by cadmium in hepatocytes

Mitochondrial quality control (MQC) is implicated in cell death induced by heavy metal pollutants. Dynamin-related protein 1 (Drp1) regulates mitochondrial fission, which is an important part of MQC. Retinoblastoma (RB) protein can regulate MQC in a transcription-independent manner. Necroptosis plays a critical role in hepatic pathologies such as inflammatory, infectious, and xenobiotics-induced injury and diseases. We aimed to explore the role and mechanism of Drp1 interaction with RB in hepatocyte's necroptosis caused by cadmium (Cd). CdCl₂ was employed to expose to Institute of Cancer Research (ICR) mice and human hepatic L02 cells. CdCl₂ exposure induced necroptosis and hepatic injury both in vivo and in vitro. Moreover, Drp1 and RB protein were up-regulated and translocated to mitochondria in CdCl₂-exposed hepatocytes. Inhibition of Drp1 with siRNA (siDNM1L) or inhibitors not only suppressed the RB expression and its mitochondrial translocation, but also alleviated MQC disorder, necroptosis, and hepatotoxicity caused by CdCl₂. Moreover, blocking Drp1 with metformin rescued necroptosis and hepatic injury triggered by CdCl₂. RB was proved to directly interact with Drp1 at mitochondria to form a complex which then bound to receptor interaction protein kinase (RIPK3) and enhanced the formation of necrosome after CdCl₂ exposure. In summary, we found a new molecular mechanism of regulated cell death that Drp1 interacted with RB and promoted them mitochondrial translocation to mediate necroptosis and hepatic injury in hepatocytes induced by Cd-exposure. The mitochondrial Drp1-RB axis would be a novel target for the protection cells from xenobiotics triggering hepatic injury and diseases involved in necroptosis.

Effects of gestational diabetes mellitus on stereological parameters and extravillous trophoblast cells of placenta compared to the control group

The quantitative changes of extravillous trophoblast cells (EVTs) in placenta of gestational diabetes mellitus (GDM) patients were investigated compared to healthy controls using stereological methods. The volumetric parameters of the placenta and EVTs were estimated using Cavalieri's principle and Physical Disector stereological methods. The placental volume and weight in the GDM group increased compared to the control group (p < .05). The difference in the total volume of intervillous space and blood vessels of the placenta between GDM and control groups was statistically significant (p < .05). In addition, there was a significant difference in the volume density of blood vessels and syncytiotrophoblast between the GDM group and the control group (p < .05). The total volume of the EVTs, nucleus and cytoplasm diameter, volume of the nucleus and cytoplasm, nucleus to cytoplasm ratio (N/C) of EVTs and the total number of EVTs per unit volume of the placenta in the GDM group showed a significant increase compared to the controls (p < .05). Impact statement What is already known on this subject? It is reported that extravillous trophoblast cells (EVTs) played an important role in pregnancy complications. There are limited studies on the quantitative changes of EVTs in the placental bed of GDM patients. What do the results of this study add? The results showed that volumetric parameters and number of EVTs were significantly altered in GDM placentas. These changes can be associated with disturbances in trophoblastic invasion in GDM pregnancies and may affect the development and survival of the embryo. What are the implications of these findings for clinical practice and/or further research? In the present study, there is a new insight to placenta structure that probably could be useful to understanding possible mechanisms of pregnancy complications and the achievement of new therapeutic strategies. Further investigation on the molecular biology of these cells in pregnancy complications will be needed to clarify this hypothesis.

Placenta structural changes in heavy smoking mothers: a stereological aspect

OBJECTIVE

Smoking during pregnancy is able to alter the structure and function of the placenta. In the present study, quantitative changes of the placenta in smoking mothers were investigated compared to healthy controls by Cavalieri's point counting method.

METHODS

Twenty placentas from heavy smoking mothers and non-smoker controls (n = 10 in each group) were selected. Systematic uniform random sampling (SURS) was used for sample selection and tissue sectioning. Quantitative parameters of the placenta in the selected sections were estimated after Masson's trichrome staining. Differences between the two groups were determined by the Mann Whitney U test and the significance level was set at p < .05.

RESULTS

Results showed that there was a significant difference in the placental weight, total volume of placenta, intervillous space, fibrin and syncytiotrophoblast between the heavy smoker group and the control group (p < .05). The differences in the volume density of fibrin and blood vessels between the smoker and control groups were statistically significant (p < .05).

CONCLUSIONS

Our findings suggested that quantitative parameters of the placenta significantly changed in placentas from the smoker group compared to controls. These changes can probably be associated with pregnancy complications in smoking mothers and may affect the development and survival of the fetus and even its future life.

Exposure of cadmium via smoking and drinking water on zinc levels of biological samples of malnutrition pregnant women: A prospective cohort study

In present study, the interaction of a toxic (cadmium) and essential element (zinc) was determined in scalp hair of pregnant and non-pregnant women resident in a rural area of Thraparkar, Pakistan, where malnutrition is prevalent. In the malnourished group (pregnant and nonpregnant women), deficiency of the essential element (zinc) due to malnutrition and exposure of toxic metal (cadmium) via non-branded cigarette smoking and drinking groundwater were carried out. For comparative purposes, scalp hair samples were also collected from pregnant and non-pregnant women, residing in Hyderabad city, consuming municipal treated drinking water and smoking branded cigarette, termed as the reference group. The domestic treated and ground water, as well as the branded and non-branding cigarettes were analysed for cadmium (Cd). Whereas Zinc (Zn) and Cd were determined in scalp hair samples of malnutrioned and reference women. The groundwater indicated 5 to 12 fold higher levels of Cd than the WHO recommended value in drinking water. Whereas the content of Cd in locally made non-branded cigarettes was found to be two fold higher than branded cigarettes. These data indicate that the malnourished pregnant and non-pregnant smokers women group had three to four times higher levels of Cd in their scalp hair samples than those values obtained for reference non smokers. Whereas, the content of Zn in scalp hair samples of the reference women was ∼20% higher than the malnourished group.

Placenta - Worth Trying? Human Maternal Placentophagia: Possible Benefit and Potential Risks

The use of placenta preparations as an individual puerperal remedy can be traced back to historical, traditional practices in Western and Asian medicine. To evaluate the ingestion of processed placenta as a puerperal remedy, the potential risks (trace elements, microorganisms) and possible benefit (hormones in the placental tissue) of such a practice are discussed in this article based on a literature review.

Quantitative changes of extravillous trophoblast cells in heavy smoker mothers compared with healthy controls

Maternal smoking during pregnancy can induce structural and functional changes in the placenta. Placentas from heavy smoker (>20 cigarettes per day) mothers and non-smoker healthy controls (n=10 in each group) were enrolled in the present case-control study. Sample selection and sectioning were performed by systematic uniform random sampling (SURS). Selected sections were stained using Masson's trichrome to estimate quantitative parameters of placental extravillous trophoblast cells (EVTs) and the number of EVTs. Differences between groups were evaluated using the Mann-Whitney U-test, with significance set at P<0.05. There was a significant difference in placental weight and the total volume of the placenta between the heavy smoker and control groups (P<0.05). The total volume of EVTs, nucleus diameter, cytoplasm diameter, the volume of the nucleus and cytoplasm and the nucleus to cytoplasm ratio of EVTs were significantly greater in the heavy smoker compared with control group (P<0.05 for all). In placentas from heavy smokers, the total number of EVTs per unit volume of placental bed were significantly greater than in the control group (P<0.05 for both). In conclusion, the findings suggest that maternal smoking could affect fetal health by changing the quantitative parameters of the placenta, and likely the invasive properties of EVTs.

Gestation-Specific Changes in the Anatomy and Physiology of Healthy Pregnant Women: An Extended Repository of Model Parameters for Physiologically Based Pharmacokinetic Modeling in Pregnancy

BACKGROUND

In the past years, several repositories for anatomical and physiological parameters required for physiologically based pharmacokinetic modeling in pregnant women have been published. While providing a good basis, some important aspects can be further detailed. For example, they did not account for the variability associated with parameters or were lacking key parameters necessary for developing more detailed mechanistic pregnancy physiologically based pharmacokinetic models, such as the composition of pregnancy-specific tissues.

OBJECTIVES

The aim of this meta-analysis was to provide an updated and extended database of anatomical and physiological parameters in healthy pregnant women that also accounts for changes in the variability of a parameter throughout gestation and for the composition of pregnancy-specific tissues.

METHODS

A systematic literature search was carried out to collect study data on pregnancy-related changes of anatomical and physiological parameters. For each parameter, a set of mathematical functions was fitted to the data and to the standard deviation observed among the data. The best performing functions were selected based on numerical and visual diagnostics as well as based on physiological plausibility.

RESULTS

The literature search yielded 473 studies, 302 of which met the criteria to be further analyzed and compiled in a database. In total, the database encompassed 7729 data. Although the availability of quantitative data for some parameters remained limited, mathematical functions could be generated for many important parameters. Gaps were filled based on qualitative knowledge and based on physiologically plausible assumptions.

CONCLUSION

The presented results facilitate the integration of pregnancy-dependent changes in anatomy and physiology into mechanistic population physiologically based pharmacokinetic models. Such models can ultimately provide a valuable tool to investigate the pharmacokinetics during pregnancy in silico and support informed decision making regarding optimal dosing regimens in this vulnerable special population.

Unravelling the Role of Metallothionein on Development, Reproduction and Detoxification in the Wall Lizard Podarcis sicula

Metallothioneins (MTs) are an evolutionary conserved multigene family of proteins whose role was initially identified in binding essential metals. The physiological role of MT, however, has been revealed to be more complex than expected, since not only are MTs able to bind to toxic heavy metals, but many isoforms have shown specialized and alternative functions. Within this uncertainty, the information available on MTs in non-mammalian vertebrates, particularly in neglected tetrapods such as the reptiles, is even more scant. In this review, we provide a summary of the current understanding on metallothionein presence and function in the oviparous lizard Podarcis sicula, highlighting the results obtained by studying MT gene expression in most representative adult and embryonic tissues. The results demonstrate that in adults, cadmium induces MT transcription in a dose- and tissue-specific manner. Thus, the MT mRNAs appear, at least in some cases, to be an unsuitable tool for detecting environmental ion contamination. In early embryos, maternal RNAs sustain developmental needs for MT protein until organogenesis is well on its way. At this time, transcription starts, but again in a tissue- and organ-specific manner, suggesting an involvement in alternative roles. In conclusion, the spatiotemporal distribution of transcripts in adults and embryos definitively confirms that MT has deserved the title of elusive protein.

A synergistic negative effect of gestational smoke-exposure and small litter size on rat placental efficiency, vascularisation and angiogenic factors mRNA expression

Smoking increases the risk of pregnancy complications such as spontaneous abortion and low birth weight (LBW). By cigarette smoke exposure (gestational day, GD3-17), normal-litter-size pregnancy with low birth weight (NP-LBW) and small-litter-size pregnancy with normal birth weight (SP-NBW) in rats were induced. The placental weight in SP-NBW was twice the weight of the normal in contrast with the smaller placenta in NP-LBW. Compared with the normal, placental efficiency (expressed as fetus-to-placenta weight ratio) and placental vascularisation were significantly decreased in smoke exposed placentas with more obvious decrease in SP-NBW. For NP-LBW, decreased placental vascularisation was due to decreased labyrinth vascularisation which was caused by both decreased number density and diameter of fetal capillary. For SP-NBW, decreased placental vascularisation was due to reduced proportion of labyrinth in placenta and decreased labyrinth vascularisation which was caused by decreased fetal capillary number density. Real time RT-PCR analysis showed a tendency for decreased placental mRNA level of vascular endothelial growth factor (VEGF), angiopoietin-1 (Ang1) and tyrosine kinase receptor-2 (Tie2) in NP-LBW(P<0.1), and the tendency became obvious in SP-NBW(P<0.05). A tendency for decreased placental mRNA level of fms-like tyrosine kinase-1(Flt1) and angiopoietin-2 (Ang2) was also observed in SP-LBW(P<0.1). Our data demonstrated the synergistic negative effect of gestational smoke-exposure and small litter size on placental efficiency, placental vascularisation and placental angiogenic growth factor mRNA expression in rat.

Smoking, HIV, and risk of pregnancy loss

OBJECTIVE

Cigarette smoking during pregnancy increases risks of poor pregnancy outcomes including miscarriage and stillbirth (pregnancy loss), but the effect of smoking on pregnancy loss among HIV-infected women has not been explored. Here, investigated the impact of smoking on risk of pregnancy loss among HIV-positive and HIV-negative women, and estimated the potential impact of realistic smoking cessation interventions on risk of pregnancy loss among HIV-positive women.

DESIGN

We analyzed pregnancy outcomes in HIV-positive and HIV-negative participants in the Women's Interagency HIV Study between 1994 and 2014.

METHODS

We estimated effects of current smoking at or immediately before pregnancy on pregnancy loss; we controlled for confounding using regression approaches, and estimated potential impact of realistic smoking cessation interventions using a semiparametric g-formula approach.

RESULTS

Analysis examined 1033 pregnancies among 659 women. The effect of smoking on pregnancy loss differed dramatically by HIV status: adjusted for confounding, the risk difference comparing current smokers to current nonsmokers was 19.2% (95% confidence limit 10.9-27.5%) in HIV-positive women and 9.7% (95% confidence limit 0.0-19.4%) in HIV-negative women. These results were robust to sensitivity analyses. We estimated that we would need to offer a realistic smoking cessation intervention to 36 women to prevent one pregnancy loss.

CONCLUSION

Smoking is a highly prevalent exposure with important consequences for pregnancy in HIV-positive pregnant women in the United States, even in the presence of potent highly active antiretroviral therapy. This evidence supports greater efforts to promote smoking cessation interventions among HIV-positive women, especially those who desire to become pregnant.

Increasing CACNA1C expression in placenta containing high Cd level: an implication of Cd toxicity

Cadmium (Cd) has known to produce many adverse effects on organs including placenta. Many essential transporters are involved in Cd transport pathways such as DMT-1, ZIP as well as L-VDCC. Fourteen pregnant women participated and were divided into two groups: high and low Cd-exposed (H-Cd, L-Cd) groups on the basis of their residential areas, Cd concentrations in the blood (B-Cd), urine (U-Cd), and placenta (P-Cd). The results showed that the B-Cd and U-Cd were significantly increased in H-Cd group (p < 0.05). Interestingly, the P-Cd in H-Cd group was elevated (p < 0.05) and positively related to their B-Cd and U-Cd values (p < 0.05). However, the mean cord blood Cd (C-Cd) concentration in H-Cd group was not significantly increased about 2.5-fold when comparing to L-Cd group. To determine the Cd accumulation in placental tissues, metallothionein-1A (MT-1A) and metallothionein-2A (MT-2A) expressions were used as biomarkers. The results revealed that mean MT-1A and MT-2A mRNAs and MT-1/2 proteins were up-regulated in H-Cd group (p < 0.05). In addition, the Ca channel alpha 1C (CACNA1C) mRNA and protein expressions were noticeably elevated in H-Cd group (p < 0.05). From these findings, we suggested that CACNA1C might be implicated in Cd transport in human placenta.

Maternal characteristics of pregnancies with intrauterine fetal demise

OBJECTIVE

To identify maternal characteristics independently associated with pregnancies resulting in intrauterine fetal demise (IUFD).

STUDY DESIGN

This was a population-based cohort study of all births taking place at the McGill University Health Centre in Montreal, Canada, between 2001 and 2007, using the McGill University Obstetrics and Neonatal Database. Maternal characteristics were compared between pregnancies that resulted in IUFD and control pregnancies resulting in live newborns. A logistic regression analysis was constructed to identify parameters independently associated with IUFD.

RESULTS

We identified 20,744 births during the study period, 87 of which were complicated by IUFD. Mothers with IUFD were more likely to be younger, with less formal education, higher rates of smoking during pregnancy, and more fetal anomalies (42.5% vs. 7.5%, P<0.001). After exclusion of pregnancies with congenital and/or chromosomal abnormalities, less formal education (7 vs. 13.6 school years, P<0.001) and smoking during pregnancy (24% vs. 7.7%, P<0.001) remained significantly more common in pregnancies resulting in IUFD. In the multivariable regression analysis both smoking and number of maternal school years were independently associated with IUFD pregnancies (OR 2.22 for smoking, P=0.007 and OR 0.865 for number of school years, P<0.001).

CONCLUSION

Lower levels of education and smoking during pregnancy are independent predictors of IUFD.

The effects of maternal smoking on pregnancy outcome and placental histopathology lesions

OBJECTIVE

To study the effects of maternal smoking on pregnancy outcome and placental histopathology findings.

MATERIALS & METHODS

Maternal and labor characteristics and pathological reports were compared between term placentas of complicated and uncomplicated pregnancies of: heavy smokers (>10 cigarettes per day, H-smokers), moderate smokers (<10 cigarettes per day, M-smokers) and non-smokers (controls, N-smokers).

RESULTS

Birth-weights were lower in the H-smokers and M-smokers as compared to the N-smokers (p<0.001), with a higher rate of small for gestational age (SGA): 18.2%, 19.2% and 11.4%, respectively (p=0.01). Deliveries among smokers were characterized by higher rates of abnormal fetal heart rate tracings during labor as compared to non-smokers (p=0.01). Rates of placental maternal and fetal stromal-vascular supply lesions was similar between the groups.

CONCLUSIONS

Maternal smoking is associated with higher rates of SGA. Tobacco's potential influence is probably through the disruption of normal placental epigenetic patterns, not expressed in placental histopathology lesions.

Physical, behavioral, and cognitive effects of prenatal tobacco and postnatal secondhand smoke exposure

The purpose of this review is to examine the rapidly expanding literature regarding the effects of prenatal tobacco and postnatal secondhand smoke (SHS) exposure on child health and development. Mechanisms of SHS exposure are reviewed, including critical periods during which exposure to tobacco products appears to be particularly harmful to the developing fetus and child. The biological, biochemical, and neurologic effects of the small fraction of identified components of SHS are described. Research describing these adverse effects of both in utero and childhood exposure is reviewed, including findings from both animal models and humans. The following adverse physical outcomes are discussed: sudden infant death syndrome, low birth weight, decreased head circumference, respiratory infections, otitis media, asthma, childhood cancer, hearing loss, dental caries, and the metabolic syndrome. In addition, the association between the following adverse cognitive and behavioral outcomes and such exposures is described: conduct disorder, attention-deficit/hyperactivity disorder, poor academic achievement, and cognitive impairment. The evidence supporting the adverse effects of SHS exposure is extensive yet rapidly expanding due to improving technology and increased awareness of this profound public health problem. The growing use of alternative tobacco products, such as hookahs (a.k.a. waterpipes), and the scant literature on possible effects from prenatal and secondhand smoke exposure from these products are also discussed. A review of the current knowledge of this important subject has implications for future research as well as public policy and clinical practice.

Parental smoking during pregnancy and offspring cardio-metabolic risk factors at ages 17 and 32

OBJECTIVE

To examine the association of maternal and/or paternal smoking during pregnancy with offspring cardio-metabolic risk (CMR) factors at adolescence and early adulthood, taking into account socio-demographic, medical and lifestyle characteristics of parents and offspring, as well as offspring common genetic variation.

METHODS

We used a population-based cohort of all 17 003 births in Jerusalem during 1974-76, with available archival data on parental and birth characteristics. Measurements at age 17 were assessed at military induction examinations for 11 530 offspring. 1440 offspring from the original 1974-1976 birth cohort were sampled using a stratified sampling approach, and were interviewed and examined at age 32. Parental smoking during pregnancy (i.e. maternal, paternal and any parent) was primarily defined dichotomously (any number of cigarettes smoked daily by mother or father during pregnancy vs. non-smokers). Additionally, smoking was assessed by quantity of cigarettes smoked daily. Linear regression models were used to evaluate the associations of parental smoking during pregnancy with various offspring CMR factors, after controlling for potential confounders and for genetic variation in candidate genes.

RESULTS

Prevalence of exposure to parental smoking in-utero (i.e. smoking of any parent) was 53.2% and 48.4% among the 17 years old and 32 years old samples, respectively. At age 17, smoking of at least one parent during pregnancy was significantly associated with weight (B = 1.39), height (B = 0.59), BMI (B = 0.32) and pulse rate (B = -0.78) (p-values < 0.001). At age 32, parental smoking, adjusted for covariates, was associated with 2.22 kg higher mean offspring weight, 0.95 cm higher mean offspring height, 0.57 kg/m(2) higher BMI, and 1.46 cm higher waist-circumference (p-values ≤ 0.02). Similar results, reflecting a dose response, were observed when maternal and paternal smokings were assessed by number of cigarettes smoked daily.

CONCLUSIONS

This prospective study demonstrates a potential long-term adverse effect of parental smoking during pregnancy on offspring health and calls for increasing efforts to promote smoking cessation of both parents before pregnancy.

Obstetric conditions and the placental weight ratio

INTRODUCTION

To elucidate how obstetric conditions are associated with atypical placental weight ratios (PWR)s in infants born: (a) ≥37 weeks gestation; (b) at ≥33 but <37 weeks gestation; and (c) <33 weeks gestation.

METHODS

The study included all in-hospital singleton births in London, Ontario between June 1, 2006 and March 31, 2011. PWR was assessed as <10th or >90th percentile by gestational age-specific local population standards. Multivariable analysis was carried out using multinomial logistic regression with blockwise variable entry in order of temporality.

RESULTS

Baseline factors and maternal obstetric conditions associated with PWR <10th percentile were: increasing maternal height, overweight and obese body mass indexes (BMI), large for gestational age infants, smoking, and gestational diabetes. Obstetric factors associated with PWR >90th percentile were: underweight, overweight and obese BMIs, smoking, preeclampsia, placenta previa, and placental abruption. In particular, indicators of hypoxia and altered placental function were generally associated with elevated PWR at all gestations.

DISCUSSION

An association between obstetric conditions associated with fetal hypoxia and PWR ≥90th percentile was illustrated.

CONCLUSIONS

The multivariable findings suggest that the PWR is similarly increased regardless of the etiology of the hypoxia.

Optimising sample collection for placental research

Biobanks provide an important repository of samples for research purposes. However, for those samples to reflect the in vivo state, and for experimental reliability and reproducibility, careful attention to collection, processing and storage is essential. This is particularly true for the placenta, which is potentially subjected to stressful conditions during delivery, and sample collection may be delayed owing to routine postpartum inspection by clinical staff. In addition, standardisation of the collection procedure enables samples to be shared among research groups, allowing larger datasets to be established. Here, we provide an evidence-based and experts' review of the factors surrounding collection that may influence data obtained from the human placenta. We outline particular requirements for specific techniques, and propose a protocol for optimal sample collection. We recognise that the relevance of these factors, and of the sample types collected to a particular study will depend on the research questions being addressed. We therefore anticipate that researchers will select from the protocol to meet their needs and resources available. Wherever possible, we encourage researchers to extend their collection to include additional samples that can be shared on an international collaborative basis, with appropriate informed consent, to raise the quality, as well as quantity, of placental research.

Mercury, cadmium, and lead levels in human placenta: a systematic review

BACKGROUND

Placental tissue may furnish information on the exposure of both mother and fetus. Mercury (Hg), cadmium (Cd), and lead (Pb) are toxicants of interest in pregnancy because they are associated with alterations in child development.

OBJECTIVES

The aim of this study was to summarize the available information regarding total Hg, Cd, and Pb levels in human placenta and possible related factors.

METHODS

We performed a systematic search of PubMed/MEDLINE, EMBASE, Lilacs, OSH, and Web of Science for original papers on total Hg, Cd, or Pb levels in human placenta that were published in English or Spanish (1976-2011). Data on study design, population characteristics, collection and analysis of placenta specimens, and main results were extracted using a standardized form.

RESULTS

We found a total of 79 papers (73 different studies). Hg, Cd, and Pb levels were reported in 24, 46, and 46 studies, respectively. Most studies included small convenience samples of healthy pregnant women. Studies were heterogeneous regarding populations selected, processing of specimens, and presentation of results. Hg concentrations > 50 ng/g were found in China (Shanghai), Japan, and the Faroe Islands. Cd levels ranged from 1.2 ng/g to 53 ng/g and were highest in the United States, Japan, and Eastern Europe. Pb showed the greatest variability, with levels ranging from 1.18 ng/g in China (Shanghai) to 500 ng/g in a polluted area of Poland.

CONCLUSION

The use of the placenta as a biomarker to assess heavy metals exposure is not properly developed because of heterogeneity among the studies. International standardized protocols are needed to enhance comparability and increase the usefulness of this promising tissue in biomonitoring studies.

Mammalian metallothioneins: properties and functions

Metallothioneins (MT) are a family of ubiquitous proteins, whose role is still discussed in numerous papers, but their affinity to some metal ions is undisputable. These cysteine-rich proteins are connected with antioxidant activity and protective effects on biomolecules against free radicals, especially reactive oxygen species. In this review, the connection between zinc(II) ions, reactive oxygen species, heavy metal ions and metallothioneins is demonstrated with respect to effect of these proteins on cell proliferation and a possible negative role in resistance to heavy metal-based and non-heavy metal-based drugs.

The effect of smoking on early chorionic villous vascularisation

The aim of the study was to investigate whether first trimester chorionic villous vascularisation is different in women who smoked cigarettes before and during pregnancy in comparison with women who did not smoke. Placentas of smoking (>10 cigarettes/day, n = 13) and non-smoking women (n = 13), scheduled for a legal termination of a viable first trimester pregnancy for social indications, were retrieved. Placental tissues of 3-5 mm³ were whole mount CD31 immunofluorescence stained. Images of the CD31 immunofluorescence and contour of the villi were captured using an Optical Projection Tomography scanner. An immersive BARCO virtual reality system was used to create an enlarged interactive 3-dimensional hologram of the reconstructed images. Automatic volume measurements were performed using a flexible and robust segmentation algorithm that is based on a region-growing approach in combination with a neighbourhood variation threshold. The villous volume, vascular volume and vascular density were measured for the total chorionic villous tree as well as for its central and peripheral parts. No differences in maternal age and gestational age were found between non-smoking and smoking women. No differences were found in the total, central and peripheral villous tree volume and vascular volume. The central (13.4% vs. 9.5%, p=0.03) and peripheral (8.4% vs. 6.4%, p=0.02) villous tree vascular densities were increased in the smoking women as compared with the non-smoking women. In conclusion, chorionic villous vascularisation is already altered in first trimester of pregnancy in women who smoked cigarettes before and during pregnancy.

Cadmium associated with inhaled cadmium oxide nanoparticles impacts fetal and neonatal development and growth

One industrially important metal oxide nanoparticle (NP) is cadmium oxide (CdO). A study was performed using timed-pregnant CD-1 mice to determine if Cd associated with inhaled CdO NP could reach the placenta and adversely affect the developing fetus and/or neonate. Pregnant mice were exposed by inhalation either every other day to 100 μg of freshly generated CdO/m(3) (exposure 1) or daily to 230 μg CdO/m(3) (exposure 2). In each exposure, mice were exposed to CdO NP or carrier gas (control) for 2.5 h from 4.5 days post coitus (dpc) through 16.5 dpc. At 17.5 dpc, fetuses and placentas from both exposures 1 and 2 were collected, measured, and weighed. A subgroup from the second exposure was allowed to give birth, and neonates were weighed daily until weaning. Cadmium in the uterus and placenta, as well as in other maternal organs, was elevated in NP-treated mice, but was undetectable in fetuses at 17.5 dpc. Daily inhalation of 230 μg CdO NP/m(3) decreased the incidence of pregnancy (i.e., no evidence of implantation) by 23%, delayed maternal weight gain, altered placental weight, and decreased fetal length, as well as delayed neonatal growth. This study demonstrates that inhalation of CdO NP during pregnancy adversely affects reproductive fecundity and alters fetal and postnatal growth of the developing offspring.

Cadmium-induced teratogenicity in lizard embryos: correlation with metallothionein gene expression

Cadmium teratogenic effects and metallothionein expression were studied in tissues of lizard embryos at different stages of development. Incubation of eggs in cadmium contaminated soil had no effect on embryo survival, but strongly affected cranial morphogenesis. Cytological analyses demonstrated abnormalities in the development of proencephalic vesicles, mesencephalon and eyes. No defects were observed in somite or limb development. Northern blot analysis demonstrated that MT expression was much stronger in embryos developed in cadmium contaminated soil. In situ hybridization showed an early induction of MT gene expression in developing liver and gut, whereas in brain and eyes the spatial and temporal localization of MT transcripts did not change. A possible correlation between inability to induce MT expression and abnormalities observed in the head region of lizard developing embryos is suggested.

Metals in human placenta: focus on the effects of cadmium on steroid hormones and leptin

Cadmium and other metallic ions can act as metalloestrogens and endocrine disruptors of reproductive tissues and fetal development in mammals, including humans. The detrimental effects occur with respect to the synthesis of both steroid and polypeptide hormones in the placenta. Leptin is produced by the trophoblast and may regulate fetal organogenesis and development. In human term placentas, concentrations of toxic metals and their effects on steroidogenesis were assessed in healthy parturients (109 non-smokers and 99 smokers) in relation to tobacco smoking. Trace elements (cadmium, lead, iron, zinc and copper) were analyzed in placentas using atomic absorption spectroscopy, and steroid hormones (progesterone and estradiol) were assayed in placental samples by an enzyme-immunometric method. Cadmium concentrations were doubled in placentas of smokers as compared with non-smokers, and placental lead and zinc concentrations increased significantly. Placental concentrations of iron, copper, progesterone and estradiol did not differ. In addition, human trophoblast cells were co-cultured with 0, 5, 10 or 20 microm CdCl(2) for 96 h and leptin mRNA assessed by quantitative polymerase chain reaction. Leptin mRNA declined dose-responsively as a result of CdCl(2) exposure. Collectively, the results confirm that human placental tissue offers a unique opportunity to biomonitor cadmium exposure in both the maternal and the internal fetal environments. In addition, the results strongly suggest that cadmium may cause a decline in placental leptin synthesis, as we have previously shown for placental progesterone production. This may constitute further evidence of the endocrine-disrupting effects of cadmium, as a constituent of tobacco smoke, on reproduction in women.

Cadmium intoxication of pregnant rats and fetuses: interactions of copper supplementation

BACKGROUND AND AIMS

Cadmium (Cd) is an industrial and environmental pollutant that was shown to be involved in the development of some diseases. Due to high amounts of Cd in cigarettes, smokers and passive smokers are exposed to high amount of Cd. We aimed to determine whether Copper (Cu) supplementation would have a protective effect against Cd intoxication in pregnant rats and their fetuses.

METHODS

Experiments were performed on 27 adult female Wistar albino rats divided into three experimental groups. CdCl(2), CdCl(2) plus CuSO(4) and only drinking water was given to different groups for 21 days. We measured cadmium (Cd), malondialdehyde (MDA), reduced glutathione (GSH), myeloperoxidase (MPO), superoxide dismutase (SOD) and catalase (CAT) levels in dams' liver, dams' kidney, fetus liver, fetus kidney, and placenta of rats.

RESULTS

In all tissues of Cd and Cd + Cu-treated groups, Cd levels were found to be increased significantly when compared to control group. MDA levels and MPO activities were significantly increased whereas GSH levels, activities of SOD and CAT were decreased in Cd groups when compared to control group. Cu supplementation significantly prevented the increment in MDA levels and brought MPO activities back to control levels or below. Cd-induced reductions in GSH levels and SOD activities were also prevented by Cu supplementation. An increase of CAT activity after Cu supplementation was enough to revert to the control levels in some tissues.

CONCLUSIONS

Our findings suggest that Cu supplementation may have a protective effect against the Cd-induced oxidative stress in liver, kidney and placental tissues of pregnant rats and fetuses.

Effect of maternal asthma, inhaled glucocorticoids and cigarette use during pregnancy on the newborn insulin-like growth factor axis

BACKGROUND

Fetal growth varies in a sex-specific manner in response to maternal asthma during pregnancy, but the mechanisms are unclear.

OBJECTIVE

We examined the influence of maternal asthma severity and associated exposures, inhaled glucocorticoid treatment, maternal cigarette use, and fetal sex on fetal growth and placental function during pregnancy and on the newborn insulin-like growth factor (IGF) axis. STUDY SUBJECTS AND DESIGN: Fetal growth was assessed in a prospective cohort of asthmatic and non-asthmatic women (n=145). At delivery, umbilical vein plasma was collected from male (n=61, controls n=16 and asthmatic n=45) or female (n=84, controls n=22 and asthmatic n=62) fetuses. Cord plasma insulin-like growth factor (IGF) binding protein (BP)-1, IGFBP-3, IGF-1 and IGF-2 were measured by radioimmunoassay and ELISA.

RESULTS

Cord plasma IGF-1 was the main component of the neonatal IGF axis altered by asthma and cigarette use. IGF-1 was increased in the presence of mild asthma and a male fetus and decreased in the presence of a female fetus and maternal asthma with cigarette use. IGFBP-3 was also decreased in the female fetuses of pregnancies complicated by asthma and cigarette use. Inhaled glucocorticoid use for the treatment of asthma did not affect the IGF axis. The strongest overall predictor of female birth weight after accounting for asthma severity, inhaled glucocorticoid treatment and cigarette use was IGF-1. For males, the strongest predictor of birth weight was IGFBP-3.

CONCLUSION

The data suggest male and female fetuses institute different strategies in response to adverse pregnancy conditions such as asthma and cigarette use.

Genetic regulatory networks of nephrogenesis: deregulation of WT1 splicing by benzo(a)pyrene

Recent studies have identified AHR as a master regulator of Wilms' tumor suppressor gene (WT1) signaling in the developing kidney. Activation of AHR signaling by environmental chemical is associated with proteasome-mediated degradation of AHR protein, disruption of WT1 alternative splicing, and marked alterations in the regulation of genetic programs of developmental progression in the developing kidney. The complexity of genetic regulatory networks of nephrogenesis controlled by AHR-WT1 interactions will be discussed here with particular emphasis given to the biological and medical consequences that may result from deficits in nephrogenesis that compromise reserve capacity and renal function later in life. Understanding the impact of early-life environmental exposures to chemicals that disrupt AHR signaling can help minimize negative health consequences to pregnant women and their offspring.

Effects of cadmium on the expression of placental lactogens and Pit-1 genes in the rat placental trophoblast cells

Cadmium is an endocrine disrupter (ED) with detrimental effects on mammalian reproduction. The placenta is a primary target for cadmium toxicity during pregnancy. Very little of this metal crosses the placenta to the fetus, and consequently it accumulates in high concentrations in the placenta. Cadmium affects on steroid synthesis and has estrogen- and androgen-like activities. In this study, we investigated the toxic effects of cadmium on placental trophoblast cells as well as the mRNA levels of placental lactogens (PLs), which are under the control of estrogen and play a pivotal role during pregnancy. Pregnant F344 Fisher rats were injected subcutaneously with 0, 0.2, and 2.0mg/kg BW/day of cadmium (CdCl(2)) dissolved in saline from days 11 to 19 of pregnancy and were sacrificed on day 20. The mRNA levels of the PL-Iv and -II genes and Pit-1alpha and beta isotype genes, the trans-acting factor of PLs, were analyzed by Northern blot hybridization and reverse transcription-polymerase chain reaction, respectively. The frequency of the placental trophoblast cells was observed histochemically. Developmental data and apoptotic chromosomal DNA fragmentation of placental cells were also observed. The mRNA levels of PL-Iv and -II were reduced in a dose-dependent manner by cadmium. The mRNA levels of the Pit-1alpha and beta isotype genes were also reduced by cadmium. In the uterus-conjugated region of the placental junctional zone, the frequency rates of trophoblast cells were lower in the cadmium-treated groups than in the control group. High-dose cadmium exposure (2.0mg) induced not only the reduction of trophoblast cell frequency but also apoptotic chromosomal DNA fragmentation in the junctional zone of the placenta. Developmental metrics such as placental and fetal weights and a number of live fetuses, decreased, while a numbers of resorptions, dead fetuses, and post-implantation losses increased significantly (p<0.05) in the cadmium-treated groups compared to the control. These data suggested that cadmium inhibits the expression of PL genes and reduces the number of trophoblast cells in the rat placenta via an estrogen-like activity, leading to significant toxic effects on placental growth and physiological function in rats.

Gender, smoking during pregnancy and gestational age influence cord leptin concentrations in newborn infants

BACKGROUND

Low birth weight (BW), small head circumference, reduced length, increased preterm births and neuro-endocrine dysfunctions are among known consequences of smoking during pregnancy. Few studies have linked leptin to clinical features of growth restriction associated with maternal smoking and explored interaction with other determinants of size at birth, such as gender.

METHODS

Cord serum leptin concentrations were measured in 1215 term infants born to Caucasian mothers at completion of uneventful pregnancy. Serum concentrations were related to BW, gestational length, gender and maternal smoking and interaction with other determinants of size at birth evaluated.

RESULTS

Smoking was more frequent in younger (P<0.001) and shorter mothers (P=0.03) from lower socio-economic groups (SEGPs) (P<0.001). Infants born to smokers were lighter (190 g less), shorter and with smaller head circumference. Cord serum leptin concentrations were higher in girls (9.8 s.d. 7.6 ng/ml) than in boys (7.05 s.d. 5.8 ng/ml) (P<0.001). Boys were heavier (BW 3.52 s.d. 0.49 kg) than girls (3.39 s.d. 0.44 kg) (P<0.001), but girls had greater skinfold thickness measurements (sub-scapular and quadriceps skinfold thicknesses 5.5 s.d. 1.6 mm and 7.6 s.d. 1.9 mm respectively; boys 5.3 s.d. 1.6 vs 7.24+/-1.90 mm, P<0.001 respectively). Multivariate analyses showed gender (P<0.001), BW SDS (P<0.001), gestational length (P<0.001) and maternal smoking (P<0.042) as factors that influenced umbilical cord serum leptin concentrations in newborns.

CONCLUSION

Maternal smoking restrains foetal growth through placental vascular effects, and likely also via associated effects on leptin metabolism. More studies are needed to determine the influence that maternal smoking may have on placental syncytiotrophoblast and foetal adipose tissue.

Fetal growth restriction triggered by polycyclic aromatic hydrocarbons is associated with altered placental vasculature and AhR-dependent changes in cell death

Maternal cigarette smoking is considered an important risk factor associated with fetal intrauterine growth restriction (IUGR). Polycyclic aromatic hydrocarbons (PAHs) are well-known constituents of cigarette smoke, and the effects of acute exposure to these chemicals at different gestational stages have been well established in a variety of laboratory animals. In addition, many PAHs are known ligands of the aryl hydrocarbon receptor (AhR), a cellular xenobiotic sensor responsible for activating the metabolic machinery. In this study, we have applied a chronic, low-dose regimen of PAH exposure to C57Bl/6 female mice before conception. This treatment caused IUGR in day 15.5 post coitum (d15.5) fetuses and yielded abnormalities in the placental vasculature, resulting in significantly reduced arterial surface area and volume of the fetal arterial vasculature of the placenta. However, examination of the small vasculature within the placental labyrinth of PAH-exposed dams revealed extensive branching and enlargement of these vessels, indicating a possible compensatory mechanism. These alterations in vascularization were accompanied by reduced placental cell death rates, increased expression levels of antiapoptotic Xiap, and decreased expression of proapoptotic Bax, cleaved poly(ADP-ribose) polymerase-1, and active caspase-3. AhR-deficient fetuses were rescued from PAH-induced growth restriction and exhibited no changes in the labyrinthine cell death rate. The results of this investigation suggest that chronic exposure to PAHs is a contributing factor to the development of IUGR in human smokers and that the AhR pathway is involved.

Morphological and biological effects of maternal exposure to tobacco smoke on the feto-placental unit

Active and passive maternal smoking has a damaging effect in every trimester of human pregnancy. Cigarette smoke contains scores of toxins which exert a direct effect on the placental and fetal cell proliferation and differentiation and can explain the increased risk of miscarriage, fetal growth restriction (FGR) stillbirth, preterm birth and placental abruption reported by epidemiological studies. In the placenta, smoking is associated from early in pregnancy, with a thickening of the trophoblastic basement membrane, an increase in collagen content of the villous mesenchyme and a decrease in vascularisation. These anatomical changes are associated with changes in placental enzymatic and synthetic functions. In particular, nicotine depresses active amino-acid (AA) uptake by human placental villi and trophoblast invasion and cadmium decreases the expression and activity of 11 beta-hydroxysteroid dehydrogenase type 2 which is causally linked to FGR. Maternal smoking also dysregulates trophoblast expression of molecules that govern cellular responses to oxygen tension. In the fetus, smoking is associated with a reduction of weight, fat mass and most anthropometric parameters and as in the placenta with alterations in protein metabolism and enzyme activity. These alterations are the results of a direct toxic effect on the fetal cells or an indirect effect through damage to, and/or functional disturbances of the placenta. In particular, smoking interferes strongly with the fetal brain and pancreas biological parameters and induces chromosomal instability, which is associated with an increase in the risk of cancer, especially childhood malignancies.

The influence of maternal cigarette smoking on placental pathology in pregnancies complicated by abruption

OBJECTIVE

The purpose of this study was to evaluate the effect of maternal cigarette smoking on placental histology in women with abruption.

STUDY DESIGN

Data were derived from the New Jersey-Placental Abruption Study (NJ-PAS)--an ongoing, case-control study, conducted since August 2002 in 2 large hospitals in NJ. Abruption cases were identified based on a clinical diagnosis. Histologic evaluations were performed by 2 perinatal pathologists who were blinded to the abruption status. Maternal smoking during pregnancy was determined based on patient's self-report. Among abruption cases, histologic findings were compared between smokers and nonsmokers, and the association expressed as odds ratio (OR) with 95% confidence interval (CI). All analyses were adjusted for potential confounders.

RESULTS

A total of 189 abruption cases were available for analysis, of which 10.6% (n = 20) were smokers. Intervillous thrombus was more common in women who smoked (20%) than in nonsmokers (3.0%) (OR, 17.5; 95% CI, 3.1-99.4). However, placental infarcts were seen less frequently among smokers than nonsmokers (10.0% vs 32.5%; OR, 0.2; 95% CI, 0.1-0.8).

CONCLUSION

These findings suggest that different pathologic mechanisms may be responsible for the histologic findings between smokers and nonsmokers diagnosed with placental abruption.

The effects of air pollution and smoking on placental cadmium, zinc concentration and metallothionein expression

This study is designed to determine the placental zinc (Zn) and cadmium (Cd) levels in mothers who were smokers, mothers who were thought to be exposed to air pollution, and mothers who were non-smokers and to investigate the relationship between the expression of placental metallothionein (MT) binding these metals and blood progesterone level. Placental Zn and Cd levels were measured by atomic absorption spectrometry. Presence of placental MT was determined immunohistochemically. Placental changes were examined by light microscope after H&E and PAS staining. Immunohistochemical MT staining of syncytiotrophoblastic and villous interstitial cells were scored as positive or negative. Among the 92 mothers included in the study, 33 were smokers (Group I), 29 had been exposed to air pollution (Group II) and 30 were non-smoker rural residents who had never been exposed to air pollution (Group III). Mean off-spring birth weight of 3198.62+/-380.01 g and mean placenta weight of 561.38+/-111.55 g of Group II were lower when compared with those of other two groups. In Group I, mean placental Cd and Zn were 0.063+/-0.022 microg/g and 39.84+/-15.5 microg/g, respectively, being higher than in other groups. In Group II, mean placental Cd and Zn levels were higher than those of Group III. Blood progesterone levels of subjects in Group I (121 ng/ml) were the lowest of all groups. While the mean count of villi was the highest in Group III; the highest mean count of syncytial knots was in Group II. Thickening of vasculo-syncytial membrane was most prominent in Group I. Similarly, MT staining was positive and very dense in 72.7% (24/33) of cases in Group I (p<or=0.05). MT staining was positive in 69.0% (29/20) and denser in Group II cases compared to 36% (11/30) in Group III (p<or=0.05). This study showed that smoking increased Cd levels in placenta and accompanied an increase in placental MT expression immunohistochemically. The effects of exposure to air pollution are equally harmful as smoking related effects.

Sex-specific differences in birth weight due to maternal smoking during pregnancy

INTRODUCTION

We investigated the sex-specific risk of maternal smoking during pregnancy on the birth weight and the proportion of small-for-gestational-age (SGA) newborns in 888,632 (49.9%) of 1,815,318 singleton births (ca. 80% of all singleton births in Germany from 1995 to 1997) in whom data on maternal cigarette consumption were available.

RESULTS AND DISCUSSION

Newborns below the 10th percentile for weight and duration of pregnancy were classified SGA. Maternal smoking during pregnancy lowers the mean birth weight and increases the risk of SGA newborns. The negative effect depends on the daily number of cigarettes consumed, and is greater in girls than in boys. In non-smokers, 9.8% of the newborns were SGA, with a sex-ratio of females:males=1, but this percentage increased with increasing number of cigarettes consumed (p<0.001), as did the sex-ratio, i.e. the negative effect of smoking on growth was greater in girls than in boys. In mild smokers (1-5 cigarettes/day), the risk of giving birth to an SGA girl was 1.7275-fold (95% CI: 1.7266-1.7284) above normal, but was 1.7143-fold (95% CI: 1.7137-1.7150) in boys. More than 21 cigarettes/day increased the risk of SGA 3.15-fold for a boy, but 3.51-fold for a girl (p<0.001).

CONCLUSION

In conclusion, particularly in heavy smokers, the negative effect of maternal smoking during pregnancy on the mean birth weight and risk of SGA is significantly greater in newborn girls than in newborn boys.

Allometric studies on growth and development of the human placenta: growth of tissue compartments and diffusive conductances in relation to placental volume and fetal mass

Correlations between placental size and fetal mass during gestation fail to account for changes in composition that accompany placental growth and maturation. This study uses stereological data on the sizes of different tissue compartments in human placentas from 10 weeks of gestation to term and relates them to placental volume and to fetal mass by means of allometric analysis. In addition, tissue dimensions are used to calculate a physiological transport measure (diffusive conductance) for the villous membrane. Histological sections randomly sampled from placentas and analysed stereologically provided estimates of structural quantities (volumes, exchange surface areas, lengths, numbers of nuclei, diffusion distances). These data were combined with a physicochemical quantity (Krogh's diffusion coefficient) in order to estimate oxygen diffusive conductances for the villous membrane and its two components (trophoblast and stroma). Allometric relationships between these quantities and placental volume or fetal mass were obtained by linear regression analyses after log-transformation. Placental tissues had different growth trajectories: most grew more rapidly than placental volume and all grew more slowly than fetal mass. Diffusion distances were inversely related to placental and fetal size. Differential growth impacted on diffusive conductances, which, again, did not improve commensurately with placental volume but did match exactly growth of the fetus. Findings show that successful integration between supply and demand can be achieved by differential tissue growth. Allometric analysis of results from recent studies on the murine placenta suggest further that diffusive conductances may also be matched to fetal mass during gestation and to fetal mass at term across species.

Stereological methods to assess tissue response for tissue-engineered scaffolds

The stereological approach can provide an objective unbiased assessment of structural change in biological systems. In this review, we elucidate the basic principles of stereology and their implementation in the analysis of tissue response to tissue-engineering scaffolds. A brief outline of tissue response parameters that can be estimated using stereological approach is included. The focus is on frequently quantified parameters in tissue response, such as host tissue infiltration, inflammatory cell numbers, angiogenesis, fibrous tissue thickness, areas of calcification, and/or necrosis, among others. Special consideration is given to sampling techniques and how these techniques can influence the reliability of the obtained results as well as minimizing potential sources of bias. These basic principles are illustrated with practical examples, where measurements are performed and estimations calculated using conventional stereological techniques. As the next generation of biomaterials continue to be developed, it is essential that researchers develop a rigorous and unbiased method of performance quantification.