Smoking before pregnancy and risk of gestational hypertension and preeclampsia

[Smoking cessation during pregnancy]

Smoking during pregnancy is associated with negative pregnancy and perinatal health outcomes. Physiological and societal particularities can modify the smoking behavior of pregnant women. Pregnancy is a teachable moment for smoking cessation. Increased nicotine clearance may lead to exacerbated tobacco withdrawal symptoms and desire to smoke, which need to be taken into account when helping pregnant smokers to quit. Although most pregnant smokers try to quit on their own, 12% of pregnant women in France reported smoking in 2021 during the 3rd trimester of pregnancy. Health care professionals should screen for tobacco consumption and assess the level of addiction. Management of smoking cessation can be multidisciplinary, including non-pharmacological support such as counselling, behavioral support, financial reward contingent on abstinence, and medication (nicotine replacement therapies). Assessment and limitation of secondhand smoke exposure (SHS) is needed because SHS can also have negative maternal and fetal consequences. Management of relapse during the postpartum period is also to be anticipated; in 2021, it concerned 22.4% of women who had stopped smoking during pregnancy. While electronic cigarette use is increasing overall and among pregnant women who smoke (5.4 before pregnancy, 1.3% during the 3rd trimester in 2021), well-conducted smoking cessation studies are necessary to assess its benefits and potential risks in this specific group of smokers.

Tobacco, nicotine, and cannabis use and exposure in an Australian Indigenous population during pregnancy: A protocol to measure parental and foetal exposure and outcomes

BACKGROUND

The Australian National Perinatal Data Collection collates all live and stillbirths from States and Territories in Australia. In that database, maternal cigarette smoking is noted twice (smoking <20 weeks gestation; smoking >20 weeks gestation). Cannabis use and other forms of nicotine use, for example vaping and nicotine replacement therapy, are nor reported. The 2021 report shows the rate of smoking for Australian Indigenous mothers was 42% compared with 11% for Australian non-Indigenous mothers. Evidence shows that Indigenous babies exposed to maternal smoking have a higher rate of adverse outcomes compared to non-Indigenous babies exposed to maternal smoking (S1 File).

OBJECTIVES

The reasons for the differences in health outcome between Indigenous and non-Indigenous pregnancies exposed to tobacco and nicotine is unknown but will be explored in this project through a number of activities. Firstly, the patterns of parental and household tobacco, nicotine and cannabis use and exposure will be mapped during pregnancy. Secondly, a range of biological samples will be collected to enable the first determination of Australian Indigenous people's nicotine and cannabis metabolism during pregnancy; this assessment will be informed by pharmacogenomic analysis. Thirdly, the pharmacokinetic and pharmacogenomic findings will be considered against maternal, placental, foetal and neonatal outcomes. Lastly, an assessment of population health literacy and risk perception related to tobacco, nicotine and cannabis products peri-pregnancy will be undertaken.

METHODS

This is a community-driven, co-designed, prospective, mixed-method observational study with regional Queensland parents expecting an Australian Indigenous baby and their close house-hold contacts during the peri-gestational period. The research utilises a multi-pronged and multi-disciplinary approach to explore interlinked objectives.

RESULTS

A sample of 80 mothers expecting an Australian Indigenous baby will be recruited. This sample size will allow estimation of at least 90% sensitivity and specificity for the screening tool which maps the patterns of tobacco and nicotine use and exposure versus urinary cotinine with 95% CI within ±7% of the point estimate. The sample size required for other aspects of the research is less (pharmacokinetic and genomic n = 50, and the placental aspects n = 40), however from all 80 mothers, all samples will be collected.

CONCLUSIONS

Results will be reported using the STROBE guidelines for observational studies.

FORWARD

We acknowledge the Traditional Custodians, the Butchulla people, of the lands and waters upon which this research is conducted. We acknowledge their continuing connections to country and pay our respects to Elders past, present and emerging. Notation: In this document, the terms Aboriginal and Torres Strait Islander and Indigenous are used interchangeably for Australia's First Nations People. No disrespect is intended, and we acknowledge the rich cultural diversity of the groups of peoples that are the Traditional Custodians of the land with which they identify and with whom they share a connection and ancestry.

County incidence and geospatial trends of early-onset hypertensive disorders of pregnancy in Kentucky, 2008-2017

BACKGROUND

Early-onset hypertensive disorders of pregnancy (eHDP) are associated with more severe maternal and infant outcomes than later-onset disease. However, little has been done to evaluate population-level trends. Therefore, in this paper, we seek to address this understudied area by describing the geospatial and temporal patterns of county-level incidence of eHDP and assessing county-level demographics that may be associated with an increased incidence of eHDP.

METHODS

Employing Kentucky certificates of live and stillbirth from 2008-2017, this ecological study detected county-level clusters of early-onset hypertensive disorders of pregnancy using SaTScan, calculated average annual percent change (AAPC) with a join point analysis, and identified county-level covariates (% of births to women ≥ 35 years of age, % with BMI ≥ 30 kg/m², % currently smoking, % married, and % experienced eHDP) with a fixed-effects negative binomial regression model for longitudinal data with an autoregressive (AR) correlation structure offset with the natural log of the number of births in each county and year.

RESULTS

County-level incidence of eHDP had a non-statistically significant increase of almost 3% (AAPC: 2.84, 95% CI: -4.26, 10.46), while maternal smoking decreased by almost 6% over the study period (AAPC:-5.8%, 95%CI: -7.5, -4.1), Risk factors for eHDP such as pre-pregnancy BMI ≥ 30 and proportion of births to women ≥ 35 years of age increased by 2.3% and 3.4% respectively (BMI AAPC:2.3, 95% CI: 0.94, 3.7; ≥ 35 years AAPC:3.4, 95% CI: 0.66, 6.3). After adjusting for race, county-level proportions of college attainment, and maternal smoking throughout pregnancy, counties with the highest proportion of births to women with BMI ≥ 30 kg/m² reported an eHDP incidence 20% higher than counties with a lower proportion of births to mothers with a BMI ≥ 30 kg/m² and a 20% increase in eHDP incidence (aRR = 1.20, 95% CI: 1.00, 1.44). We also observed that counties with the highest proportion vs. the lowest of mothers ≥ 35 years old (> 6.1%) had a 26% higher incidence of eHDP (RR = 1.26, 95%CI: 1.04, 1.50) compared to counties with the lowest incidence (< 2.5%). We further identified two county-level clusters of elevated eHDP rates. We also observed that counties with the highest vs. lowest proportion of mothers ≥ 34 years old (> 6.1% vs. < 2.5%) had a 26% increase in the incidence of eHDP (RR = 1.26, 95% CI: 1.04, 1.50). We further identified two county-level clusters of elevated incidence of eHDP.

CONCLUSIONS

This study identified two county-level clusters of eHDP, county-level covariates associated with eHDP, and that while increasing, the average rate of increase for eHDP was not statistically significant. This study also identified the reduction in maternal smoking over the study period and the concerning increase in rates of elevated pre-pregnancy BMI among mothers. Further work to explore the population-level trends in this understudied pregnancy complication is needed to identify community factors that may contribute to disease and inform prevention strategies.

Reevaluating the protective effect of smoking on preeclampsia risk through the lens of bias

Preeclampsia is a hypertensive disorder that is usually diagnosed after 20 weeks' gestation. Despite the deleterious effect of smoking on cardiovascular disease, it has been frequently reported that smoking has a protective effect on preeclampsia risk and biological explanations have been proposed. However, in this manuscript, we present multiple sources of bias that could explain this association. First, key concepts in epidemiology are reviewed: confounder, collider, and mediator. Then, we describe how eligibility criteria, losses of women potentially at risk, misclassification, or performing incorrect adjustments can create bias. We provide examples to show that strategies to control for confounders may fail when they are applied to variables that are not confounders. Finally, we outline potential approaches to manage this controversial effect. We conclude that there is probably no single epidemiological explanation for this counterintuitive association.

Identification of the Obstetric Factors Increasing Tendency to Smoking Cessation During Pregnancy

INTRODUCTION

Cigarette, one of the various forms of tobacco, is the most commonly used tobacco product in Turkey and in the world. Cigarette has several negative effects on general health and is a major problem in the pregnancy period. This study aims to identify pregnancy-related factors that affect the tendency to smoking cessation and their effect levels in pregnant women who continue to smoke during pregnancy.

METHOD

The sample of this descriptive and cross-sectional study was 430 pregnant women who smoked. Data were collected through an original interview form and face-to-face interviews. Data analysis was performed using chi-square, independent t test, and multiple logistic regression model in terms of demographic, obstetric, maternal, and fetal features.

RESULTS

The average number of cigarettes smoked before pregnancy was 13.28 ± 8.62, whereas the average number of cigarettes smoked during pregnancy was 6.60 ± 7.64. The tendency to decrease smoking increases 2.8 times ( OR = 2.825, 95% CI [1.631, 4.895]) with the number of pregnancies and approximately 2 times in case of a planned pregnancy ( OR = 1.946, 95% CI [1.076, 3.520]). The frequency of having prenatal visits showed a weak but significant relationship with the number of abortuses and the number of living children.

CONCLUSIONS

Developing a risk map in line with the findings of the study and considering the obstetric features of smoking women could enable to hypothesize about the types of behaviors in smoking in the following processes of pregnancy. With the precautions to be taken, the negative effects of smoking on maternal and fetal health could be prevented or minimized.

Racial disparity in gestational diabetes mellitus and the association with sleep-disordered breathing and smoking cigarettes: a cross-sectional study

BACKGROUND

Gestational diabetes mellitus (GDM) prevalence has risen in the U.S. and worldwide over the past decade. Minority groups, especially Asian and Hispanic women, are often disproportionately affected by GDM. Identifying modifiable risk factors such as sleep-disordered breathing and smoking and their interaction with race/ethnicity could play a pivotal role in preventing GDM.

METHODS

Data from the 2017-2018 National Health and Nutrition Examination Surveys (NHANES) were used to run a survey-weighted multivariable logistic regression assessing the association between sleep-disordered breathing and smoking with GDM among women aged 15-60 (n = 1326). The interaction term of the two predictors and race/ethnicity was introduced to the model to assess the interaction effect. The analyses were adjusted for age, marital status, education level, and BMI.

RESULTS

Approximately 13% of the participants reported having GDM. The lowest prevalence was observed among Non-Hispanic Blacks (7.8%) and the highest was among Other (15.5%). Sleep-disordered breathing was significantly associated with GDM (OR = 1.69, 95% CI 1.05, 2.73). No statistically significant association was observed between smoking and GDM (OR = 1.03, 95% CI 0.47, 2.27), and neither was the association between race/ethnicity and GDM. Furthermore, none of the interaction effects were statistically significant.

CONCLUSION

Preventive strategies targeting GDM should focus on improving modifiable risk factors, such as sleep-disordered breathing. It is important to screen women with sleep-disordered breathing and monitor their blood sugar before becoming pregnant to prevent the development of GDM. Future studies are recommended to understand the lower prevalence of GDM among Black women and the higher prevalence among "Other" race group which mostly includes Asian women.

A cross-sectional examination of the early-onset hypertensive disorders of pregnancy and industrial emissions of toxic metals using Kentucky birth records, 2008-2017

This cross-sectional study assessed geospatial patterns of early-onset hypertensive disorders of pregnancy (eHDP) in primiparous mothers and exposure to industrial emissions using geocoded residential information from Kentucky live (N = 210,804) and still (N = 1,247) birth records (2008-2017) and census block group estimates of aerosol concentrations of arsenic (As), cadmium (Cd), chromium (Cr), lead (Pb), mercury (Hg), selenium (Se), and zinc (Zi) from the Risk Screening Environmental Indicators (RSEI) model. A latent class analysis allowed for the identification of four district exposure classes-As, Cd, and Pb (12.6%); Se and Zi (21.4%); Pb and Cr (8%); and low or no exposures (57.9%). Women classified as having a high probability of exposure to both Pb and Cr had a statistically significantly greater prevalence of eHDP after adjusting for demographic factors (aPR = 1.22, 95% CI: 1.04, 1.44) relative to those with low or no exposure. Our findings contribute to the emerging literature on the association of metal exposures with pregnancy outcomes.

Modulation of preeclampsia by the cholinergic anti-inflammatory pathway: Therapeutic perspectives

The cholinergic anti-inflammatory pathway (CAP) is vital for the orchestration of the immune and inflammatory responses under normal and challenged conditions. Over the past two decades, peripheral and central circuits of CAP have been shown to be critically involved in dampening the inflammatory reaction in a wide array of inflammatory disorders. Additionally, emerging evidence supports a key role for CAP in the regulation of the female reproductive system during gestation as well as in the advent of serious pregnancy-related inflammatory insults such as preeclampsia (PE). Within this framework, the modulatory action of CAP encompasses the perinatal maternal and fetal adverse consequences that surface due to antenatal PE programming. Albeit, a considerable gap still exists in our knowledge of the precise cellular and molecular underpinnings of PE/CAP interaction, which hampered global efforts in safeguarding effective preventive or therapeutic measures against PE complications. Here, we summarize reports in the literature regarding the roles of peripheral and reflex cholinergic neuroinflammatory pathways of nicotinic acetylcholine receptors (nAChRs) in reprogramming PE complications in mothers and their progenies. The possible contributions of α7-nAChRs, cholinesterases, immune cells, adhesion molecules, angiogenesis, and endothelial dysfunction to the interaction have also been reviewed.

Central Australian Aboriginal women's pregnancy, labour and birth outcomes following maternal smokeless tobacco (pituri) use, cigarette use or no-tobacco use: a prospective cohort study

BACKGROUND

Outcomes related to maternal smoked tobacco (cigarette) use have been substantially examined over the past 50 years with resultant public health education targeted towards the reduction of use during pregnancy. However, worldwide the effects of maternal smokeless tobacco use have been less well explored and in Australia, there has been no examination of maternal outcomes in relation to the use of Australian Nicotiana spp. (tobacco plant) as a smokeless tobacco, colloquially known as pituri. The aim of this study is to describe the maternal outcomes of a group of central Australian Aboriginal women in relation to their self-reported tobacco use.

METHODS

Eligible participants were > 18 years of age, with a singleton pregnancy, > 28 weeks gestation, and who planned to birth at the Alice Springs Hospital (the major regional hospital for central Australia, in the Northern Territory, Australia). The sample consisted of 73 conveniently recruited women categorized by tobacco-use status as no-tobacco users (n = 31), pituri chewers (n = 19), and smokers (n = 23).

RESULTS

There were differences in the groups in relation to teenage pregnancies; 35% of no-tobacco users, compared with 5% of pituri users, and 13% of smokers were <  20 years of age. The chewers had a higher rate (48%) of combined pre-existing and pregnancy-related elevated glucose concentrations compared with smokers (22%) and no-tobacco users (16%).The pituri chewers had the lowest rate (14%) of clinically significant post-partum hemorrhage (> 1000 ml) compared with 22% of smokers and 36% of the no-tobacco users.

CONCLUSIONS

This is the first research to examine pituri use in pregnancy and the findings indicate possible associations with a range of adverse maternal outcomes. The use of smokeless tobacco needs to be considered in maternal healthcare assessment to inform antenatal, intrapartum and postpartum care planning.

IMPLICATIONS FOR PUBLIC HEALTH

Female smokeless tobacco use is a global phenomenon and is particularly prevalent in low and middle income countries and in Indigenous populations. The findings contribute to the developing knowledge around maternal smokeless tobacco use and maternal outcomes. Maternal screening for a broader range of tobacco and nicotine products is required.

NOTE TO READERS

In this research, the central Australian Aboriginal women chose the term 'Aboriginal' to refer to themselves, and 'Indigenous' to refer to the broader First Peoples. That choice has been maintained in the reporting of the research findings.

The association between smoking during pregnancy and hypertensive disorders of pregnancy: A systematic review and meta-analysis

BACKGROUND

Smoking is a major public health problem. However, its association with hypertensive disorders of pregnancy (HDP) is inconclusive.

OBJECTIVE

To find the association between smoking during pregnancy and HDP.

SEARCH STRATEGY

We searched PubMed, Ovid and Cochrane Library up to March, 2021, using terms including "smoking" and "HDP".

SELECTION CRITERIA

Observational studies that assessed the relationship between smoking during pregnancy and HDP were included.

DATA COLLECTION AND ANALYSIS

Odds ratios (OR) and 95% confidence intervals (CI), and other necessary data were extracted. Stata16.0 MP was used to analyze statistics.

MAIN RESULTS

A total of 13 studies were included. Meta-analysis revealed that smoking during pregnancy was a protective factor for HDP (OR 0.78, 95% CI 0.67-0.92), gestational hypertension (OR 0.74, 95% CI 0.69-0.79), and pre-eclampsia (OR 0.65, 95% CI 0.58-0.73). Subgroup analysis showed that smoking during pregnancy was a risk factor for HDP in Asia but a protective factor in Europe and North America. Neither quitting smoking before pregnancy nor during pregnancy had a statistically significant association with HDP.

CONCLUSION

This meta-analysis revealed that smoking during pregnancy might prevent HDP, gestational hypertension, and pre-eclampsia. Smoking during pregnancy was a risk factor for HDP in Asia but a protective factor in Europe and North America.

Comparison among research, home, and office blood pressure measurements for pregnant women: The TMM BirThree Cohort Study

Blood pressure (BP) measurements of pregnant women have been collected in offices and at home for previous research. However, it remains uncertain whether there is difference between research BP, defined as BP measured for the purpose of epidemiological research and BP measured at home or in an office. Therefore, the present study aimed to compare research BP with home and unstandardized office BP. Research, home, and office BP were measured among pregnant women who participated in the Tohoku Medical Megabank Project Birth and Three-Generation Cohort Study (TMM BirThree Cohort Study). Research BP was measured twice at our research center while the participant was seated and after resting for 1-2 minutes. Research, home, and office BP were compared and agreement among the values was assessed. Differences among research, home, and office BP values and possible factors affecting differences were analyzed. Among 656 pregnant women, the mean (± standard deviations) research systolic (S), diastolic (D) BP, home SBP, home DBP office SBP, and office DBP were 103.8 ± 8.5, 61.8 ± 7.3, 104.4 ± 9.2, 61.2 ± 6.8, 110.5 ± 10.8, and 63.8 ± 8.7mmHg, respectively. Research SBP value was lower than home value (P = .0072; difference between mean research and home BP: -0.61 ± 7.8 mmHg). Research SBP and DBP values were lower than office values (P < .0001 for both SBP and DBP; means ± standard deviations of differences between research and office BP: 6.7 ± 10.1 and 2.0 ± 8.5 mmHg for SBP and DBP, respectively). In conclusion, when research BP is measured under conditions controlled, research BP can give close values to home BP for pregnant women.

Smoking cessation in early-pregnancy, gestational weight gain and subsequent risks of pregnancy complications

OBJECTIVE

Smoking cessation is associated with weight gain. We first examined the associations of smoking cessation in early-pregnancy with gestational weight gain and subsequently evaluated the risks of pregnancy complications among women who quit smoking in early-pregnancy according to their gestational weight gain.

METHODS

In a population-based prospective cohort study among 7,389 women, we measured weight in each pregnancy period. Information on smoking and pregnancy complications was obtained from questionnaires and medical records.

RESULTS

As compared to continued smoking during pregnancy, smoking cessation in early-pregnancy was not associated with gestational weight gain. Smoking cessation in early-pregnancy was associated with decreased risks of delivering small-for-gestational-age infants (Odds Ratio (OR) 0.52 (95 % Confidence Interval (CI) 0.37, 0.75)), but with increased risks of pre-eclampsia (OR 2.07 (95 % CI 1.01, 4.27)) and delivering large-for-gestational-age infants (OR 2.11 (95 % CI 1.45, 3.09)). Among women who quit smoking in early-pregnancy with >12 kg weight gain, the risks of pre-eclampsia and delivering large-for-gestational-age infants were slightly increased.

CONCLUSION

As compared to continued smoking during pregnancy, smoking cessation in early-pregnancy is not associated with increased gestational weight gain. Among women who quit smoking in early-pregnancy, higher gestational weight gain does not strongly affect their risks of pregnancy complications.

[Consequences of Active Cigarette Smoking in Pregnancy - CNGOF-SFT Expert Report and Guidelines on the management of smoking during pregnancy]

OBJECTIVE

To synthesize knowledge on the consequences of active smoking in pregnancy.

METHODS

The MedLine database, the Cochrane Library and French and foreign guidelines from 1999 to 2019 have been consulted.

RESULTS

Active maternal smoking is associated with an increased risk of first trimester complications such as early miscarriage and ectopic pregnancy with a dose-effect relationship between smoking and those risks. Active cigarette smoking during pregnancy is associated with an increased risk of certain type of birth defects, placenta abruptio, placenta previa, stillbirth and cesarean delivery. Active maternal smoking is associated with a reduced risk of pre-eclampsia. Children born to mothers who smoke are more at risk of premature birth and low birth weight with a dose-effect relationship for those two risks.

CONCLUSION

Apart from preeclampsia which is reduced in case of active maternal smoking, perinatal morbidity is increased among women who smoke during their pregnancy.

The relationship between gestational active and passive smoking and early postpartum complications

Objective: The studies especially on the postpartum effects of passive exposure to cigarette smoke are limited, although there are studies investigating early and late postpartum effects of active smoking during pregnancy. This study aimed to investigate the relationship between gestational active and passive smoking and early postpartum complications.Methods: This study was conducted with 217 women in the early postpartum period (first 7 days after birth) in a research hospital, gynecology and obstetrics clinic. Data were collected using the questionnaire form prepared in accordance with the literature by the face-to-face interview method. They were evaluated in the SPSS 23.0 program, and descriptive statistics, logistic regression analysis in multivariate analyses and multiple linear regression analysis were in the analysis of data.Results: In the study, it was found that active smoking was associated with cardiac anomalies (OR = 0.18, 95% = CI 0.03-0.91; p = .039), developmental retardation (OR = 0.11, 95% CI = 0.02-0.56; p = .008), respiratory distress (OR = 0.12, 95% CI = 0.02-0.58; p = .008), low birth weight (OR = 0.22, 95% CI = 0.08-0.57; p = .003) and premature labor (OR = 0.30, 95% CI = 0.16-0.59; p = .000) while passive smoking was associated with premature labor (OR = 0.47, 95% CI = 0.25-0.89; p = .021). It was determined that passive smoking was associated with gestational hypertension (OR 0.30, 95% CI = 0.09-0.85; p = .025). Nevertheless, it was found that active smoking negatively affected the infant's birth weight (p = .000), length (p = .040), head circumference (p = .000) and breastfeeding (p = .005).Conclusion: Gestational active and passive smoking has significant negative effects on maternal and infant health in the early postpartum period.

First-trimester smoking cessation in pregnancy did not increase the risk of preeclampsia/eclampsia: A Murmansk County Birth Registry study

Background

Although prior studies have shown that smoking reduces preeclampsia/eclampsia risk, the consequence of giving up this habit during pregnancy should be assessed. The aims of the current study were threefold: (i) describe maternal characteristics of women with preeclampsia/eclampsia; (ii) examine a possible association between the number of cigarettes smoked daily during pregnancy and the development of this affliction; and (iii) determine if first-trimester discontinuation of smoking during pregnancy influences the risk.

Methods

A registry-based study was conducted using data from the Murmansk County Birth Registry (MCBR). It included women without pre-existing hypertension, who delivered a singleton infant during 2006–2011 and had attended the first antenatal visit before 12 week of gestation. We adjusted for potential confounders using logistic regression.

Results

The prevalence of preeclampsia/eclampsia was 8.3% (95%CI: 8.0–8.6). Preeclampsia/eclampsia associated with maternal age, education, marital status, parity, excessive weight gain and body mass index at the first antenatal visit. There was a dose-response relationship between the number of smoked cigarettes per day during pregnancy and the risk of preeclampsia/eclampsia (adjusted OR_{1-5 cig/day} = 0.69 with 95%CI: 0.56–0.87; OR_{6-10 cig/day} = 0.65 with 95%CI: 0.51–0.82; and OR_{≥11 cig/day} = 0.49 with 95%CI: 0.30–0.81). There was no difference in this risk among women who smoked before and during pregnancy and those who did so before but not during pregnancy (adjusted OR = 1.10 with 95%CI: 0.91–1.32).

Conclusions

Preeclampsia/eclampsia was associated with maternal age, education, marital status, parity, excessive weight gain, and body mass index at the first antenatal visit. There was a negative dose-response relationship between the number of smoked cigarettes per day during pregnancy and the odds of preeclampsia/eclampsia. However, women who gave up smoking during the first trimester of gestation had the same risk of preeclampsia/eclampsia as those who smoked while pregnant. Consequently, antenatal clinic specialists are advised to take these various observations into account when counselling women on smoking cessation during pregnancy.

Revisiting the discriminatory accuracy of traditional risk factors in preeclampsia screening

BACKGROUND

Preeclampsia (PE) is associated with a high risk of perinatal morbidity and mortality. However, there is no consensus in the definition of high-risk women.

AIM

To question current definition of high PE risk and propose a definition that considers individual heterogeneity to improves risk classification.

METHODS

A stratified analysis by parity was conducted using the Swedish Birth Register between 2002-2010 including 626.600 pregnancies. The discriminatory accuracy (DA) of traditional definitions of high-risk women was compared with a new definition based on 1) specific combinations of individual variables and 2) a centile cut-off of the probability of PE predicted by a multiple logistic regression model.

RESULTS

None of the classical risk-factors alone reached an acceptable DA. In multiparous, any combination of a risk-factor with previous PE or HBP reached a +LR>10. The combination of obesity and multiple pregnancy reached a good DA particularly in the presence of previous preeclampsia (positive likelihood ratio (LR+) = 26.5 or chronic hypertension (HBP) LR+ = 40.5. In primiparous, a LR+>15 was observed in multiple pregnancies with the simultaneous presence of obesity and diabetes mellitus or with HBP. Predicted probabilities above 97 centile in multiparous and 99 centile in primiparous provided high (LR+ = 12.5), and moderate (LR+ = 5.85), respectively. No one risk factor alone or in combination provided a LR- sufficiently low to rule-out the disease.

CONCLUSIONS

In preeclampsia prediction the combination of specific risk factors provided a better discriminatory accuracy than traditional single risk approach. Our results contribute to a more personalized risk estimation of preeclampsia.

Cigarette smoking during pregnancy and preeclampsia risk: a systematic review and meta-analysis of prospective studies

Although evidence from epidemiological studies evaluating the association between cigarette smoking during pregnancy and preeclampsia risk has been systematically reviewed, the findings have been out of date. To further clarify the relationship, we conducted this comprehensive meta-analysis of prospective studies. We searched PubMed and Web of Science up to August 2015 to identify prospective studies that evaluated the association between cigarette smoking during pregnancy and preeclampsia risk. Random-effects models were used to estimate summarized relative risk (RR) and 95% confidence intervals (CIs). Seventeen prospective studies involving 62,089 preeclampsia patients from a total of approximately 1.8 million subjects were included. Overall, there was a significant negative association between smoking during pregnancy and incidence of preeclampsia (RR = 0.67, 95% CI: 0.60–0.75), with significant heterogeneity (I² = 91.7%). Such an inverse association was also detected in strata of subgroup analyses according to study location, study sample size, parity of populations, singleton pregnancy, and adjustment for potential confounders including maternal age, diabetes mellitus, chronic hypertension, body mass index, and gender of infant. In summary, this meta-analysis suggests that smoking during pregnancy is inversely associated with incidence of preeclampsia. Further large scale multi-center prospective studies are warranted to validate our findings.

Maternal obesity increases oxidative stress in the newborn

OBJECTIVE

Obesity before pregnancy is associated with a greater risk for the offspring to develop obesity and diabetes in childhood and adulthood. The aim of the present study was to determine the association between maternal overweight or obesity before pregnancy and newborn oxidative stress (OS).

METHODS

Seventy-two mother-child pairs were divided according to the pre-gestational body mass index (BMI) of the mothers as follows: eutrophic (n = 21), overweight (n = 32), and obese (n = 19). Malondialdehyde (MDA) and nitric oxide (NO) were measured in the plasma of a blood sample from the newborn's umbilical cord.

RESULTS

The MDA levels of newborns increased with maternal BMI (P = 0.001), as did the levels of NO (P = 0.019). There was a direct correlation between MDA and NO levels in each of the three groups (eutrophic: R(2)  = 0.59, P < 0.001; overweight: R(2)  = 0.45, P < 0.001; and obese: R(2)  = 0.26, P = 0.024).

CONCLUSIONS

Maternal overweight and obesity before pregnancy are associated with increased OS in the offspring.

Maternal Smoking History Enhances the Expression of Placental Growth Factor in Invasive Trophoblasts at Early Gestation Despite Cessation of Smoking

Maternal smoking during early pregnancy is associated with a reduced risk for preeclampsia even after smoking cessation during pregnancy. Although the pathophysiology of preeclampsia has not been established, placental growth factor (PlGF) is believed to be a key factor. The aim of this study was to assess the effect of maternal smoking on the PlGF expression in invasive trophoblasts at early gestation. We collected villous tissues from women requesting surgical termination due to non-medical reasons at 7-8 weeks of gestation. The maternal smoking status was evaluated by measuring the serum cotinine level and patients were divided into two groups: active smokers and non-smokers. After separating invasive trophoblasts from villous tissues cultured initially under 2% O2 for 24 hours, the separated invasive trophoblasts were cultured under 2% or 8% O2 for 48 hours. The expression levels of the PlGF gene in villous tissue specimens and in invasive trophoblasts cultured after the conditions were quantified using qRT-PCR. The levels of PlGF protein in the medium were quantified using an ELISA. The gene expression level of PlGF in the villi in the active-smokers was significantly higher than that of the non-smokers. In comparison of the invasive trophoblasts under normoxia and oxygenated conditions, the ratio of PlGF gene expression and protein expression under oxygenation (2% O2+8% O2 / 2% O2+2% O2) in the active-smokers were both significantly higher than in the non-smokers. Maternal smoking history appears to stimulate PlGF expression in invasive trophoblasts under oxygenated conditions. This may be one of several causes leading to the protective effect of maternal smoking on preeclampsia.

Associations of anxiety disorders, depressive disorders and body weight with hypertension during pregnancy

The purpose of this study was to prospectively examine the relationships between maternal DSM-IV-TR anxiety disorders, depressive disorders, and body mass index (BMI) with arterial hypertension and blood pressure during pregnancy. In the Maternal Anxiety in Relation to Infant Development (MARI) study, N = 306 women were enrolled in early pregnancy and repeatedly assessed during peripartum period. DSM-IV-TR anxiety and depressive disorders prior to pregnancy, lifetime anxiety/depression liability, and BMI during early pregnancy were assessed with the Composite International Diagnostic Interview for Women (CIDI-V). Based on their prepregnancy status, all participants were assigned to one of the following initial diagnostic groups: no anxiety nor depressive disorder (no AD), pure depressive disorder (pure D), pure anxiety disorder (pure A), and comorbid anxiety and depressive disorder (comorbid AD). Blood pressure measurements were derived from medical records. Arterial hypertension during pregnancy was defined by at least two blood pressure values ≥140 mmHg systolic and/or ≥90 mmHg diastolic. N = 283 women with at least four documented blood pressure measurements during pregnancy were included in the analyses. In this sample, N = 47 women (16.6 %) were identified with arterial hypertension during pregnancy. Women with comorbid AD (reference group: no AD) had a significantly higher blood pressure after adjustment for age, parity, smoking, occupation, household income, and education (systolic: linear regression coefficient [β] = 3.0, 95 % confidence interval [CI] = 0.2-5.7; diastolic, β = 2.3, 95 % CI = 0.1-4.4). Anxiety liability was associated with an increased risk of hypertension (odds ratio [OR] = 1.1, 95 % CI = 1.0-1.3) and a higher systolic blood pressure (β = 0.4, 95 % CI = 0.0-0.7). The adjusted interaction model revealed a significant interaction between the diagnostic group pure A and BMI for hypertension (ORIT = 1.5, 95 % CI = 1.1-2.1). Especially, women with a lifetime history of comorbid anxiety and depression and obese pregnant women with a lifetime history of pure anxiety disorder should be informed about their heightened risk of hypertension, monitored with regular blood pressure measurements, and provided with strategies for prevention and early intervention such as changes in diet and physical activity.

Adequately diversified dietary intake and iron and folic acid supplementation during pregnancy is associated with reduced occurrence of symptoms suggestive of pre-eclampsia or eclampsia in Indian women

Background/Objective

Pre-eclampsia or Eclampsia (PE or E) accounts for 25% of cases of maternal mortality worldwide. There is some evidence of a link to dietary factors, but few studies have explored this association in developing countries, where the majority of the burden falls. We examined the association between adequately diversified dietary intake, iron and folic acid supplementation during pregnancy and symptoms suggestive of PE or E in Indian women.

Methods

Cross-sectional data from India’s third National Family Health Survey (NFHS-3, 2005-06) was used for this study. Self-reported symptoms suggestive of PE or E during pregnancy were obtained from 39,657 women aged 15-49 years who had had a live birth in the five years preceding the survey. Multivariable logistic regression analysis was used to estimate the association between adequately diversified dietary intake, iron and folic acid supplementation during pregnancy and symptoms suggestive of PE or E after adjusting for maternal, health and lifestyle factors, and socio-demographic characteristics of the mother.

Results

In their most recent pregnancy, 1.2% (n=456) of the study sample experienced symptoms suggestive of PE or E. Mothers who consumed an adequately diversified diet were 34% less likely (OR: 0.66; 95% CI: 0.51-0.87) to report PE or E symptoms than mothers with inadequately diversified dietary intake. The likelihood of reporting PE or E symptoms was also 36% lower (OR: 0.64; 95% CI: 0.47-0.88) among those mothers who consumed iron and folic acid supplementation for at least 90 days during their last pregnancy. As a sensitivity analysis, we stratified our models sequentially by education, wealth, antenatal care visits, birth interval, and parity. Our results remained largely unchanged: both adequately diversified dietary intake and iron and folic acid supplementation during pregnancy were associated with a reduced occurrence of PE or E symptoms.

Conclusion

Having a adequately diversified dietary intake and iron and folic acid supplementation in pregnancy was associated with a reduced occurrence of symptoms suggestive of PE or E in Indian women.

Opioid Abuse and Dependence during Pregnancy

Background:

The authors investigated nationwide trends in opioid abuse or dependence during pregnancy and assessed the impact on maternal and obstetrical outcomes in the United States.

Methods:

Hospitalizations for delivery were extracted from the Nationwide Inpatient Sample from 1998 to 2011. Temporal trends were assessed and logistic regression was used to examine the associations between maternal opioid abuse or dependence and obstetrical outcomes adjusting for relevant confounders.

Results:

The prevalence of opioid abuse or dependence during pregnancy increased from 0.17% (1998) to 0.39% (2011) for an increase of 127%. Deliveries associated with maternal opioid abuse or dependence compared with those without opioid abuse or dependence were associated with an increased odds of maternal death during hospitalization (adjusted odds ratio [aOR], 4.6; 95% CI, 1.8 to 12.1, crude incidence 0.03 vs. 0.006%), cardiac arrest (aOR, 3.6; 95% CI, 1.4 to 9.1; 0.04 vs. 0.01%), intrauterine growth restriction (aOR, 2.7; 95% CI, 2.4 to 2.9; 6.8 vs. 2.1%), placental abruption (aOR, 2.4; 95% CI, 2.1 to 2.6; 3.8 vs. 1.1%), length of stay more than 7 days (aOR, 2.2; 95% CI, 2.0 to 2.5; 3.0 vs. 1.2%), preterm labor (aOR, 2.1; 95% CI, 2.0 to 2.3; 17.3 vs. 7.4%), oligohydramnios (aOR, 1.7; 95% CI, 1.6 to 1.9; 4.5 vs. 2.8%), transfusion (aOR, 1.7; 95% CI, 1.5 to 1.9; 2.0 vs. 1.0%), stillbirth (aOR, 1.5; 95% CI, 1.3 to 1.8; 1.2 vs. 0.6%), premature rupture of membranes (aOR, 1.4; 95% CI, 1.3 to 1.6; 5.7 vs. 3.8%), and cesarean delivery (aOR, 1.2; 95% CI, 1.1 to 1.3; 36.3 vs. 33.1%).

Conclusions:

Opioid abuse or dependence during pregnancy is associated with considerable obstetrical morbidity and mortality, and its prevalence is dramatically increasing in the United States. Identifying preventive strategies and therapeutic interventions in pregnant women who abuse drugs are important priorities for clinicians and scientists.

Hypertension in pregnancy

Hypertensive disorders of pregnancy represent the second commonest cause of direct maternal death and complicate an estimated 5-10 % of pregnancies. Classification systems aim to separate hypertension similar to that seen outside pregnancy (chronic and gestational hypertension) from the potentially fatal pregnancy-specific conditions. Preeclampsia, HELLP syndrome, and eclampsia represent increasing severities of this disease spectrum. The American College of Obstetricians and Gynecologists' 2013 guidelines no longer require proteinuria as a diagnostic criterion, because of its variable appearance in the disease spectrum. The cause involves inadequate cytotrophoblastic invasion of the myometrium, resulting in placental hypoperfusion and diffuse maternal endothelial dysfunction. Changes in angiogenic and antiangiogentic peptide profiles precede the onset of clinical preeclampsia. Women with preeclampsia should be closely monitored and receive magnesium sulfate intravenously if severe features, HELLP syndrome, or eclampsia occur. Definitive therapy is delivery of the fetus. Hypertension in pregnancy increases future maternal risk of hypertension and cardiovascular disorders.

Plasma cotinine indicates an increased risk of preeclampsia in previous and passive smokers

OBJECTIVE

Self-reported tobacco smoking in pregnancy has been consistently associated with a decreased risk of developing preeclampsia, but the evidence has been limited and inconsistent for previous and passive smokers. Misclassifications and inaccuracies of self-reported tobacco exposure may disguise the true relationship. This study aimed to assess the association of gestational hypertension and preeclampsia with maternal smoking status as ascertained by plasma cotinine.

STUDY DESIGN

This was a prospective study of 605 pregnant women without chronic hypertension. Maternal smoking status at 24-26 weeks' gestation was defined by plasma cotinine: >3.0 ng/mL "current smokers," 0.20-3.00 ng/mL "previous and passive smokers," and <0.20 ng/mL "nonsmokers."

RESULTS

Compared to nonsmokers, the risk of developing preeclampsia did not change significantly for current smokers, but increased significantly (adjusted odds ratio, 6.06; 95% confidence interval, 2.32-15.85; P < .001) for previous and passive smokers. There were no significant differences in the risk of developing gestational hypertension only.

CONCLUSION

Previous and passive smoking may increase the risk of preeclampsia. Avoidance of exposure to environmental tobacco smoke in pregnancy may decrease the risk of preeclampsia.

Maternal active and passive smoking and hypertensive disorders of pregnancy: risk with trimester-specific exposures

BACKGROUND

The inverse association between prenatal smoking and preeclampsia is puzzling, given the increased risks of prematurity and low birthweight associated with both smoking and preeclampsia. We analyzed the Norwegian Mother and Child Birth Cohort (MoBa) to determine whether the associations varied by timing of prenatal smoking.

METHODS

We conducted an analysis of 74,439 singleton pregnancies with completed second- and third- trimester questionnaires. Active and passive smoke exposure by trimester were determined by maternal self-report, and covered the period of preconception through approximately 30 weeks' gestation. Adjusted odds ratios (ORs) and 95% confidence intervals (CIs) were calculated.

RESULTS

Rates of active smoking declined dramatically during pregnancy: for trimester 1, 23%; trimester 2, 9%; and trimester 3, 8%. Active smoking in the third trimester was associated with reduced odds of preeclampsia and gestational hypertension, with the strongest association among continuous smokers (for preeclampsia, OR= 0.57 [95% CI = 0.46-0.70]). Women who quit smoking before the third trimester had approximately the same risk of preeclampsia and gestational hypertension as nonsmokers. There was some evidence of dose-response, with the heaviest smokers (more than eight cigarettes per day) having the lowest risks of preeclampsia (0.48 [0.32-0.73]) and gestational hypertension (0.51 [0.28-0.95]). There was little evidence of an association with passive smoking exposure.

CONCLUSION

The association between smoking and preeclampsia varies substantially according to the timing and intensity of exposure. A better understanding of the biologic pathways that underlie these associations may provide important clues to the etiology of preeclampsia and the development of effective clinical interventions.

Hypertension in pregnancy

Hypertension in pregnancy is diagnosed on systolic blood pressure greater than or equal to 140 mm Hg and/or diastolic greater than or equal to 90 mm Hg. The classification systems separate chronic and gestational hypertension from preeclampsia. Significant uncertainty regarding optimal management is reflected in the differing major international society recommendations. Blood pressure treatment is designed to minimize maternal end-organ damage. Methyldopa, labetalol, hydralazine, and nifedipine are oral options; angiotensin-converting enzyme inhibitors and angiotensin receptor antagonists are contraindicated. Women with preeclampsia should be closely monitored and receive intravenous magnesium sulfate.

Coordinated DNA methylation and gene expression changes in smoker alveolar macrophages: specific effects on VEGF receptor 1 expression

Cigarette smoking is implicated in numerous diseases, including emphysema and lung cancer. The clinical expression of lung disease in smokers is not well explained by currently defined variations in gene expression or simple differences in smoking exposure. Alveolar macrophages play a critical role in the inflammation and remodeling of the lung parenchyma in smoking-related lung disease. Significant gene expression changes in alveolar macrophages from smokers have been identified. However, the mechanism for these changes remains unknown. One potential mechanism for smoking-altered gene expression is via changes in cytosine methylation in DNA regions proximal to gene-coding sequences. In this study, alveolar macrophage DNA from heavy smokers and never smokers was isolated and methylation status at 25,000 loci determined. We found differential methylation in genes from immune-system and inflammatory pathways. Analysis of matching gene expression data demonstrated a parallel enrichment for changes in immune-system and inflammatory pathways. A significant number of genes with smoking-altered mRNA expression had inverse changes in methylation status. One gene highlighted by this data was the FLT1, and further studies found particular up-regulation of a splice variant encoding a soluble inhibitory form of the receptor. In conclusion, chronic cigarette smoke exposure altered DNA methylation in specific gene promoter regions in human alveolar macrophages.

Interpregnancy change in smoking habits and risk of preeclampsia: a population-based study

BACKGROUND

Maternal smoking has been associated with decreased risk of preeclampsia; however, it is uncertain whether this association is causal. An argument for causality would be strengthened if changes in smoking status across consecutive pregnancies were related to the risk of preeclampsia.

METHODS

We used data from the National Swedish Birth Register to ascertain the associations between changes in smoking status during the first two successive pregnancies and risk of preeclampsia in the second pregnancy in 371,627 women between 1992 and 2006. Multivariable logistic regression models were used to estimate adjusted odds ratios (OR) and 95% confidence intervals (CI).

RESULTS

Compared to women who did not smoke in either pregnancy, the risk of preeclampsia was reduced in women who smoked in both pregnancies (adjusted OR = 0.54; 95% CI = 0.47, 0.63), in those who only smoked in second pregnancy (OR = 0.76; 95% CI = 0.58, 0.99) and, to a lesser extent, in women who smoked only in the first pregnancy (OR = 0.81; 95% CI = 0.70, 0.94). History of preeclampsia in the first pregnancy did not substantially modify these associations.

CONCLUSION

These data add support to a causal interpretation of the observed inverse association between smoking during pregnancy and risk of preeclampsia.

Angiogenic factors and preeclampsia

Preeclampsia, a hypertensive disorder peculiar to pregnancy, is a systemic syndrome that appears to originate in the placenta and is characterized by widespread maternal endothelial dysfunction. Until recently, the molecular pathogenesis of phenotypic preeclampsia was largely unknown, but recent observations support the hypothesis that altered expression of placental anti-angiogenic factors are responsible for the clinical manifestations of the disease. Soluble Flt1 and soluble endoglin, secreted by the placenta, are increased in the maternal circulation weeks before the onset of preeclampsia. These anti-angiogenic factors produce systemic endothelial dysfunction, resulting in hypertension, proteinuria, and the other systemic manifestations of preeclampsia. The molecular basis for placental dysregulation of these pathogenic factors remains unknown, and as of 2011 the role of angiogenic proteins in early placental vascular development was starting to be explored. The data linking angiogenic factors to preeclampsia have exciting clinical implications, and likely will transform the detection and treatment of preeclampsia.

Preeclampsia and the risk of large-for-gestational-age infants

OBJECTIVE

We sought to compare the risk of giving birth to large-for-gestational-age (LGA) infants in women with and without preeclampsia, after adjustment for obesity and glucose intolerance.

STUDY DESIGN

We conducted secondary analysis of a prospective database of pregnant women with and without preeclampsia who delivered infants from 1998 through 2006 at Massachusetts General Hospital (n = 17,465).

RESULTS

The risk of LGA was similar in women with and without preeclampsia (odds ratio, 0.81; 95% confidence interval, 0.59-1.14). After adjustment for body mass index, glucose intolerance, and other factors, the risk of LGA was significantly lower in women with preeclampsia compared to those without preeclampsia (odds ratio, 0.69; 95% confidence interval, 0.49-0.96). Stratified analysis in groups with a higher risk of LGA revealed that preeclampsia has a similar effect on the risk of LGA regardless of maternal obesity, glucose intolerance, parity, and race.

CONCLUSION

Preeclampsia appears to be characterized by reduced, and not increased, fetal growth.

Maternal smoking and blood pressure in different trimesters of pregnancy: the Generation R study

OBJECTIVE

Smoking during pregnancy is a risk factor for various adverse birth outcomes but lowers the risk of preeclampsia. Cardiovascular adaptations might underlie these associations. We examined the associations of smoking in different trimesters of pregnancy with repeatedly measured blood pressure and the risks of preeclampsia and pregnancy-induced hypertension in a low-risk population-based cohort of 7106 pregnant women.

METHODS

This study was embedded in a population-based prospective cohort study from early pregnancy onwards. Smoking and systolic and diastolic blood pressures were assessed by questionnaires and physical examinations in each trimester of pregnancy. Information about preeclampsia and pregnancy-induced hypertension was obtained from medical records.

RESULTS

Compared to nonsmoking women, both first-trimester-only and continued smoking were associated with a steeper increase for systolic blood pressure and a lowest mid-pregnancy level and steeper increase thereafter for diastolic blood pressure throughout pregnancy. We did not find any significant associations in risk of preeclampsia for first-trimester-only smoking (odds ratio of 1.28, 95% confidence interval 0.74, 2.21) and continued smoking (odds ratio of 0.83, 95% confidence interval 0.50, 1.36), respectively.

CONCLUSIONS

Our results suggest that both first-trimester-only and continued smoking are associated with persistent maternal cardiovascular adaptations during pregnancy. Strategies for prevention of smoking during pregnancy should be focused on the preconception period. The effects of early and late-pregnancy smoking on the risk of preeclampsia should be further explored. Our results should be carefully interpreted to the general population of pregnant women.

Nicotine and cotinine affect the release of vasoactive factors by trophoblast cells and human umbilical vein endothelial cells

OBJECTIVE

To examine nicotine (N) and cotinine (C) effects on trophoblast cells (TCs) and human umbilical vein endothelial cells (HUVEC) secretion of soluble fms-like tyrosine kinase (sFlt-1), soluble endoglin (sENG), placental growth factor (PlGF), transforming growth factor-beta (TGF-beta) and vascular endothelial growth factor (VEGF).

STUDY DESIGN

Human placentas and umbilical cords were collected from uncomplicated pregnancies at term from a total of 24 non-smoking women with a history of normal blood pressure. TCs and HUVEC were cultured for 24 h with C or N (from 10(-12) to 10(-7) M).

MAIN OUTCOME MEASURES

sFlt-1, sENG, PlGF, TGF-beta and VEGF release and messenger RNA (mRNA) expression were evaluated by ELISA and real-time polymerase chain reaction (PCR), respectively.

RESULTS

N and C reduced sFlt-1, sENG and PlGF release by TCs and TGF-beta release by HUVEC. Conversely, N and C increased PlGF secretion, while N alone increased sFlt-1 release by HUVEC. N and C were able to modulate VEGF mRNA expression in HUVEC.

CONCLUSIONS

Our results suggest that N and C affect the balance of some important vasoactive factors released by TCs and HUVEC. This might be one of the possible mechanism through which smoke reduces the risk of hypertensive disorders during pregnancy as well as contributes to the well known detrimental effects of smoking on fetal development.

The risk of adverse pregnancy outcomes is increased in preeclamptic women who smoke compared with nonpreeclamptic women who do not smoke

OBJECTIVE

Maternal smoking and preeclampsia independently increase the risk of adverse pregnancy outcomes; however, smoking decreases the risk of preeclampsia. We sought to estimate the risk of adverse pregnancy outcomes among preeclamptic women who smoke and hypothesized that this risk would be increased, compared with nonpreeclamptic women who smoke or preeclamptic women who do not smoke.

STUDY DESIGN

With the use of the Niday Perinatal Database and multiple logistic regressions, we estimated the risk of adverse pregnancy outcomes in nonpreeclamptic women who smoke, preeclamptic women who do not smoke, and preeclamptic women who smoke in relation to nonpreeclamptic women who do not smoke.

RESULTS

The incidence of adverse pregnancy outcomes was more than twice as high among preeclamptic women who smoke as among nonpreeclamptic women who do not smoke. The following data were observed: small-for-gestational-age infant (odds ratio [OR], 3.40; 95% CI, 2.27-4.89), preterm birth (OR, 5.77; 95% CI, 4.50-7.35), very preterm birth (OR, 5.44; 95% CI, 3.51-8.11), abruption (OR, 6.16; 95% CI, 3.05-11.01), Apgar <4 at 5 minutes (OR, 3.11; 95% CI, 1.48-5.72), and stillbirth (OR, 3.39; 95% CI, 1.33-6.99).

CONCLUSION

Smoking decreases the risk of preeclampsia, but smokers with preeclampsia have an increased risk for adverse pregnancy outcomes.

Tobacco Use During Pregnancy and Preeclampsia Risk

Preeclampsia is a leading cause of maternal and infant mortality and morbidity worldwide. Both Swedish snuff and cigarette smoke include nicotine, but combustion products accompany only smoking. The aims of this study were to compare the effects of Swedish snuff and cigarette smoking on preeclampsia risk and to estimate whether changes in tobacco habits during pregnancy affect the risk of developing term preeclampsia. We used information from the Swedish Birth Register on all singleton births in Sweden during the years 1999–2006 (n=612 712). Compared with nontobacco users, women who used snuff in early pregnancy had an adjusted odds ratio (OR) for preeclampsia of 1.11 (95% CI: 0.97 to 1.28). The corresponding ORs for light and heavy smokers were 0.66 (95% CI: 0.61 to 0.71) and 0.51 (95% CI: 0.44 to 0.58), respectively, with ORs lower for term than preterm preeclampsia. Compared with nontobacco users, women who smoked in early pregnancy but had quit smoking before late pregnancy (weeks 30 to 32) had an adjusted OR for term preeclampsia of 0.94 (95% CI: 0.83 to 1.08). The corresponding OR for women who did not use tobacco in early pregnancy but had started to smoke before late pregnancy was 0.65 (95% CI: 0.50 to 0.85). We conclude that tobacco combustion products rather than nicotine are the probable protective ingredients against preeclampsia in cigarette smoke. Because change of smoking habits during pregnancy influence risk, we further conclude that it is the smoking habits in the middle or late rather than in the beginning of pregnancy that seem to affect the risk of preeclampsia.

Pathogenesis of preeclampsia

Preeclampsia is a systemic syndrome that occurs in 3 to 5% of pregnant women and classically manifests as new-onset hypertension and proteinuria after 20 weeks of gestation. Preeclampsia is a leading cause of maternal and neonatal morbidity and mortality. The only known cure is delivery of the placenta. Recent discoveries, however, have led to important advances in understanding the pathogenesis of the condition. Placental antiangiogenic factors are upregulated and disrupt the maternal endothelium. This change in the normal angiogenic balance toward an antiangiogenic state can result in hypertension, proteinuria, glomerular endotheliosis, HELLP (hemolysis, elevated liver enzymes, and low platelets) syndrome, and cerebral edema-the clinical signs of preeclampsia and eclampsia. The regulation of these antiangiogenic factors in the placenta is unknown. The recent discoveries of upregulated antiangiogenic factors provide promise for future testing to predict and diagnose preeclampsia as well as therapeutic targets for amelioration of the clinical disease.

Preeclampsia: the role of angiogenic factors in its pathogenesis

Preeclampsia, a systemic syndrome of pregnancy clinically characterized by new onset of proteinuria and hypertension, is associated with significant morbidity and mortality to both mothers and fetuses. The pathogenesis of preeclampsia has been enigmatic; this review will focus on understanding the origins of this disorder. Preeclampsia originates in the placenta, starting with inadequate cytotrophoblast invasion and ending with widespread maternal endothelial dysfunction. Production of placental anti-angiogenic factors, specifically soluble fms-related tyrosine kinase 1 and soluble endoglin, have been shown to be upregulated in preeclampsia. These placental anti-angiogenic factors are released into the maternal circulation; their actions disrupt the maternal endothelium and result in hypertension, proteinuria, and the other systemic manifestations of preeclampsia. The molecular basis for placental dysregulation of these pathogenic factors remains unknown, remains unknown. Hypoxia is likely an important regulator. Other factors such as alterations in the renin-angiotensin-aldosterone axis, immune maladaption, excessive shedding of trophoblast debris, oxidative stress, and genetic factors likely contribute to the pathogenesis of the abnormal placentation. As of 2009, the only successful treatment for preeclampsia is delivery. No definitive preventive strategies have been identified. However, several of the recent observations related to phenotypic causality provide stimuli for the development of novel therapies.

Consequences of smoking and caffeine consumption during pregnancy in women with type 1 diabetes

OBJECTIVE

To test the hypothesis that, in women with type 1 diabetes, prenatal smoking and caffeine consumption during pregnancy are associated with an increased risk of adverse maternal and perinatal outcomes.

METHODS

A secondary analysis of data on pregnant women with type 1 diabetes from an interdisciplinary program of Diabetes in Pregnancy. Women were interviewed monthly, by a trained non-medical member of the research team, using a standardized questionnaire, to ascertain daily smoking habits and caffeine consumption.

RESULTS

Smoking and caffeine information were available on 191 pregnancies, 168 progressing beyond 20 weeks of gestation. Early pregnancy smoking (OR 3.3, 95% CI 1.2, 8.7) and caffeine consumption (OR 4.5, 95% CI 1.2, 16.8) were associated with increased risk of spontaneous abortion when controlling for age, years since diagnosis of diabetes, previous spontaneous abortion, nephropathy and retinopathy. Smoking throughout pregnancy was significantly associated with decreased birth weight and prolonged neonatal hospital stay. Smoking throughout pregnancy (OR 0.2, 95% 0.1, 1.0) and caffeine consumption after 20 weeks (OR 0.3, 95% CI 0.1, 1.0) were associated with reduced risk of pre-eclampsia.

CONCLUSIONS

Caffeine consumption during early pregnancy, regardless of glycemic control, increases the risk of spontaneous abortion. Smoking throughout pregnancy and caffeine consumption are associated with reduced risk of pre-eclampsia.

Cigarette smoking and risk of gestational diabetes: a systematic review of observational studies

BACKGROUND

Gestational diabetes is a prevalent disease associated with adverse outcomes of pregnancy. Smoking as been associated with glucose intolerance during pregnancy in some but not all studies. Therefore, we aimed to systematically review all epidemiological evidence to examine the association between cigarette smoking during pregnancy and risk of developing gestational diabetes mellitus.

METHODS

We conducted a systematic review of articles published up to 2007, using PubMed, Embase, LILACS e CINAHL to identify the articles. Because this review focuses on studies of smoking during pregnancy, we excluded studies evaluating smoking outside pregnancy. Two investigators independently abstracted information on participant's characteristics, assessment of exposure and outcome, and estimates for the association under study. We evaluated the studies for publication bias and performed heterogeneity analyses. We also assessed the effect of each study individually through sensitivity analysis.

RESULTS

We found and critically reviewed 32 studies, of which 12 met the criteria for inclusion in the review. Most of the studies provided only unadjusted measurements. Combining the results of the individual studies, we obtained a crude odds ratio of 1.03 (99% CI 0.85-1.25). Only 4 studies presented adjusted measurements of association, and no association was found when these alone were analyzed (OR 0.95; 99% CI 0.85-1.07). Subgroup analysis could not be done due to small sample size.

CONCLUSION

The number of studies is small, with major heterogeneity in research design and findings. Taken together, current data do not support an association between cigarette smoking during pregnancy and the risk of gestational diabetes.