Smoking and placenta previa: a meta-analysis

Female smoking does not affect live birth rate after frozen thawed blastocyst transfer cycle

PURPOSE

The development of vitrification and blastocyst culture have recently led to a rapidly growing number of single frozen thawed blastocyst transfer (FBT) cycles worldwide. Although the impact of female smoking on spontaneous fertility is well established, its effect on assisted reproductive technologies (ART) outcome is still controversial, and no study has specifically evaluated its effect on FBT cycles' outcome.

METHODS

This retrospective study was conducted in all consecutive FBT cycles conducted between 2012 and 2021 in a single University-based ART centre. Endometrial preparation was standard and based on hormonal replacement therapy. One or two blastocysts were transferred according to couple's history and embryo quality. Female smoking status was recorded for each cycle, and the association between female smoking status and Live Birth Rate (LBR) after FBT cycle was evaluated with univariate and multivariate analysis.

RESULTS

A total of 1537 FBT cycles performed in non-smoking women and 397 FBT cycles performed in smoking women were included in the analysis. No independent association between female smoking status and LBR in FBT cycles was found after logistic regression (OR=1.07 [0.79-1.45], p = 0.649).

CONCLUSION

Our study suggests that female smoking might not impair endometrial receptiveness in non-stimulated FBT cycles. Further studies should nevertheless consider assessing more precisely the current smoking exposure.

Factors and outcomes for placental anomalies: An umbrella review of systematic reviews and meta-analyses

Background

Placental anomalies, including placenta previa (PP), placenta accreta spectrum disorders (PAS), and vase previa (VP), are associated with several adverse foetal-neonatal and maternal complications. However, there is still a lack of robust evidence on the pathogenesis and adverse outcomes of the diseases. Through this umbrella review, we aimed to systematically review existing meta-analyses exploring the factors and outcomes for pregnancy women with placental anomalies.

Methods

We searched PubMed, Embase, Web of Science, and the Cochrane Library from inception to February 2023. We used AMSTAR 2 to assess the quality of the reviews and estimated the pooled risk and 95% confidence intervals (CIs) for each meta-analysis.

Results

We included 34 meta-analyses and extracted 55 factors (27 for PP, 22 for PAS, and 6 for VP) and 16 outcomes (12 for PP, and 4 for VP) to assess their credibility. Seven factors (maternal cocaine use (for PP), uterine leiomyoma (for PP), prior abortion (spontaneous) (PP), threatened miscarriage (PP), maternal obesity (PP), maternal smoking (PAS), male foetus (PAS)) had high epidemiological evidence. Twelve factors and six outcomes had moderate epidemiological evidence. Twenty-two factors and eight outcomes showed significant association, but with weak credibility.

Conclusions

We found varying levels of evidence for placental anomalies of different factors and outcomes in this umbrella review.

Registration

PROSPERO: CRD42022300160.

Placenta previa in in vitro fertilization and unassisted pregnancies-is there a difference in perinatal outcomes and placental histology?

INTRODUCTION

In-vitro-fertilization (IVF) is an independent risk factor for placenta previa (PP). Our aim was to study this link by comparing the clinical characteristics and placental histology of pregnancies complicated by PP in IVF versus unassisted pregnancies.

METHODS

A retrospective-cohort study of deliveries with PP between 2008 and 2021. Placental histology, obstetric and neonatal outcomes were compared between IVF and unassisted pregnancies. Included, were singleton deliveries complicated by PP at gestational weeks (GA) >24.

RESULTS

A total of 182 pregnancies were included - 23 IVF pregnancies (IVF group) and 159 unassisted pregnancies (Control group). The control group was characterized by higher gravidity (p = .007) and parity (p < .001) and a trend of more past cesarean deliveries, whereas the IVF group- by a higher rate of nulliparity (p < .001) and diabetes mellitus (p = .04). The control group was characterized by a higher rate of placental weight below the 10th percentile (47.8 versus 13.9%, p = .001) and by a trend of a lower overall placental weight. No differences were noted in maternal and fetal vascular lesions.

DISCUSSION

While PP in non-assisted pregnancies is probably associated with previous CDs, in IVF it is more "sporadic," and may complicate any index pregnancy. A lower placental weight was more prevalent in the control group, supporting the concept that pregnancies complicated by PP following IVF can be attributed to initial abnormal location of placentation, rather than an underlying pathological uterine segment of implantation. Nevertheless, IVF and unassisted pregnancies entail similar perinatal outcomes in cases of PP.

Interaction between smoking during pregnancy and gestational diabetes mellitus and the risk of cesarean delivery: evidence from the National Vital Statistics System 2019

OBJECTIVE

To explore the interaction between smoking during pregnancy (SDP) and gestational diabetes mellitus (GDM) on the risk of cesarean delivery.

METHODS

This retrospective cohort study utilized data from the National Vital Statistics System (NVSS) 2019. The NVSS database provides data on births and deaths as well as maternal characteristics in the United States. The duration of follow-up was 38.74 ± 2.12 weeks. The outcome was the method of delivery, including vaginal and cesarean delivery. The multivariate logistic regression model was adopted to assess the associations of SDP and GDM with the method of delivery. The interaction between SDP and GDM was examined via calculating the relative excess risk of interaction (RERI), the attributable proportion of interaction (API) and the synergy index (S). Subgroup analyses were conducted based on age, race, prepregnancy body mass index (BMI), and primiparity.

RESULTS

The study included 3352615 puerperae. Compared with women who did not smoke during pregnancy, those who smoked during pregnancy had a significantly higher risk of cesarean delivery [odds ratio (OR)=1.07, 95% confidence intervals (CI): 1.05-1.10, p < 0.001]; women with GDM had a significantly greater risk of cesarean delivery than those without (OR = 1.31, 95%CI: 1.30-1.33, p < 0.001). In contrast to women who did not smoke during pregnancy and did not have GDM, those who smoked during pregnancy and had GDM exhibited an increased risk of a cesarean section (OR = 1.47, 95%CI: 1.40-1.54, p < 0.001). RERI was 0.08 (95%CI: 0.01-0.15), API was 0.06 (95%CI: 0.01-0.10), and S was 1.21 (95%CI: 1.04-1.40) suggested that there was an interaction between SDP and GDM, and it was a synergistic effect. There was a synergism between SDP and GDM in women of non-advanced age (RERI = 0.07, 95%CI: 0.001-0.15; API = 0.05, 95%CI: 0.003-0.10; S = 1.17, 95%CI: 1.001-1.36), in white women (RERI = 0.08, 95%CI: 0.004-0.16; API = 0.05, 95%CI: 0.01-0.10; S = 1.19, 95%CI: 1.02-1.39), in women who were overweight before pregnancy (RERI = 0.13, 95%CI: 0.05-0.21; API = 0.08, 95%CI: 0.04-0.13; S = 1.33, 95%CI: 1.14-1.55), and in primiparae (RERI = 0.20, 95%CI: 0.08-0.31; API = 0.12, 95%CI: 0.06-0.19; S = 1.50, 95%CI: 1.23-1.84).

CONCLUSION

SDP and GDM were associated with an increased risk of cesarean delivery, and a synergistic effect existed between SDP and GDM on the risk of cesarean delivery, especially in women of non-advanced age, white women, women who were overweight before pregnancy, and primiparae.

Racial/Ethnic Disparities Impact the Real-World Effectiveness of a Multicomponent Maternal Smoking Cessation Program: Findings from the CTTP Cohort

INTRODUCTION

Smoking during pregnancy adversely affects perinatal outcomes for both women and infants. We conducted a retrospective cohort study of the state-funded Comprehensive Tobacco Treatment Program (CTTP) - the largest maternal tobacco cessation program in San Bernardino County, California - to determine the real-world program effectiveness and to identify variables that can potentially improve effectiveness.

METHODS

During 2012-2019, women who smoked during pregnancy were enrolled in CTTP's multicomponent behavioral smoking cessation program that implemented components of known efficacy (i.e., incentives, biomarker testing, feedback, and motivational interviewing).

RESULTS

We found that 40.1% achieved prolonged abstinence by achieving weekly, cotinine-verified, 7-day abstinence during 6 to 8 weeks of enrollment. Using intention-to-treat analyses, we computed that the self-reported point prevalence abstinence rate (PPA) at the six-month telephone follow-up was 36.7%. Cohort members achieving prolonged abstinence during the CTTP were five times more likely to achieve PPA six months after CTTP. Several non-Hispanic ethnicities (Black, Native American, White, or More than one ethnicity) in the cohort were two-fold less likely (relative to Hispanics) to achieve prolonged abstinence during CTTP or PPA at six months after CTTP. This disparity was further investigated in mediation analysis. Variables such as quitting during the first trimester and smoking fewer cigarettes at enrollment were also associated with achieving PPA at six months.

DISCUSSION

Racial/ethnic health disparities that have long been linked to a higher rate of maternal smoking persist even when the pregnant smoker enrolls in a smoking cessation program.

Adverse events of recreational cannabis use during pregnancy reported to the French Addictovigilance Network between 2011 and 2020

Cannabis is the main illicit psychoactive substance used by pregnant women in France. The aim of the present national survey was to describe adverse events (AEs) of recreational cannabis use during pregnancy reported to the French Addictovigilance Network (FAN). Spontaneous reports (SRs) of AEs related to recreational cannabis use during pregnancy were collected by the FAN between 01/01/2011 and 31/01/2021 (excluding cannabidiol and synthetic cannabinoids). Over the study period, 160 SRs involved cannabis use alone or in association with tobacco (59% of all SRs) which increased. Among the 175 maternal AEs, the most commons were psychiatric AEs experienced by 96 (64.9%) women, in particular cannabis use disorders (n = 89, 60.1%), dependence (n = 54, 36.5%) and abuse (n = 21, 14.2%). Among the 57 fetal AEs, the most common were heart rhythm disorders that affected 25 (16.9%) fetuses and intrauterine growth restriction (IUGR) (n = 20, 13.5%). Among the 140 neonatal AEs, the most common were IUGR experienced by 39 (26.3%) newborns and prematurity (n = 32, 21.6%). Twelve cases of congenital malformations were observed and 4 intrauterine/neonatal deaths. Furthermore, some of these AEs (n = 13) were unexpected. Cannabis use during pregnancy has problematic consequences for both mothers and infants who need close monitoring.

Maternal Smoking and the Risk of Placenta Accreta Spectrum: A Systematic Review and Meta-Analysis

Background

This is the first meta-analysis that assessed the association between maternal smoking and the risk of placenta accreta spectrum (PAS), so this study was aimed at investigating the association between maternal smoking and PAS based on observational studies. PAS is defined as a severe obstetric complication due to the abnormal invasion of the chorionic villi into the myometrium and uterine serosa.

Methods

We searched electronic bibliographic databases including PubMed, Web of Science, Scopus, Science Direct, and Google Scholar until January 2022. The results were reported using a random effect model. The chi-square test and the I² statistic were used to assess heterogeneity. Egger's and Begg's tests were used to examine the probability of publication bias. All statistical analyses were performed at a significance level of 0.05 using Stata software, version 11.

Results

Based on the random effect model, the estimated OR of the risk of PAS associated with smoking was 1.21 (95% CI: 1.02, 1.41; I² = 4.7%). Subgroup analysis was conducted based on study design, and the result showed that the association between smoking and PAS among cohort studies was significant 1.35 (95% CI: 1.15, 1.55; I² = 0.0%).

Conclusion

Our results suggested that maternal smoking is a risk factor for the PAS. There was no heterogeneity among studies that reported an association between smoking and the PAS. The Newcastle-Ottawa Scale (NOS) was used to measure study quality.

Pregnancy Outcomes Associated With Use of Tobacco and Marijuana

Tobacco and marijuana are the most common drugs of abuse among pregnant women. Cigarettes have been extensively studied and increase the risk of miscarriage, preterm birth, premature rupture of membranes, placental dysfunction, low birth rate, stillbirth, and infant mortality. There are sparse data on the specific effects of electronic cigarettes and smokeless tobacco in pregnancy. Literature on marijuana in pregnancy is limited by confounding, bias, and the retrospective nature of studies that do not capture contemporary trends in use. However, several studies suggest an association between marijuana and fetal growth restriction, low birth weight, and neurodevelopmental differences in offspring.

Prenatal detection of placenta previa and placenta accreta spectrum: Evaluation of the routine mid-pregnancy obstetric ultrasound screening between 2013 and 2017

OBJECTIVE

To examine the detection rate of placenta previa and placenta accreta spectrum (PAS) by routine mid-pregnancy obstetric ultrasound and to estimate risk factors and prevalence within this cohort.

METHODS

This was an observational cohort study with prospectively collected data. Women attending routine mid-pregnancy obstetric ultrasound at the Sahlgrenska University Hospital with a suspected cup-shaped placenta (cohort 1, n = 339) and women diagnosed with placenta previa or PAS (cohort 2, n = 227) were analyzed according to detection rate, risk factors, and prevalence.

RESULTS

The detection rates of placenta previa and PAS were 49% (98) and 25% (14), respectively. However, 216 (99%) women with placenta previa were diagnosed prenatally, as were 14 (50%) women with PAS. In vitro fertilization was identified as the strongest independent risk factor for placenta previa (odds ratio 6.96; 95% confidence interval 4.77-10.16, P < 0.001). Risk factors were present for all women with PAS. The prevalence of placenta previa was 44/10 000 deliveries, and for PAS, 5.6/10 000 deliveries.

CONCLUSION

The existing routine mid-pregnancy obstetric ultrasound screening showed low detection rate for placenta previa and PAS. Adding risk factors could improve the detection rate.

Clinical Analysis of Factors Influencing the Development of Placenta Praevia and Perinatal Outcomes in First-Time Pregnant Patients

Objective

To analyze the risk factors associated with the development of placenta praevia (PP) in first-time pregnant patients and to observe the perinatal clinical outcomes of patients.

Methods

The clinical data of 112 pregnant women with PP (PP group) and 224 pregnant women with normal placental position (general group) who delivered in our hospital from August 2016 to August 2021 were retrospectively analyzed. Baseline demographic data such as age, gestational week, uterine history, assisted reproductive technology use, pregnancy comorbidities, pre-pregnancy body mass index (BMI), smoking, alcohol consumption, placental position, educational level, work were collected from both groups, and logistic regression models were used to analyze the factors influencing the occurrence of PP in patients with first pregnancy. Perinatal outcomes such as implementation of hemostatic treatment (uterine balloon compression, arterial ligation, and B-Lynch suture), maternal postpartum related indicators (amount of postpartum bleeding, incidence of postpartum hemorrhage, blood transfusion rate, blood transfusion volume, and length of hospital stay), and neonatal condition (birth weight, Apgar score at 1 and 5 min after birth) were counted and compared between the two groups.

Results

Histories of endometriosis, use of assisted reproductive technology, and smoking or secondhand smoke inhalation were all high risk factors for PP in patients with first pregnancies, and the proportion of maternal and neonatal adverse outcomes was significantly higher in the PP group than in the general group (P < 0.05).

Conclusion

Histories of endometriosis, smoking (secondhand smoke), and use of assisted reproductive technologies are independent risk factors for PP in patients with first pregnancies, which can increase the risk of labor and death of the newborn.

Tobacco consumption from the 1st trimester of pregnancy to 7 months postpartum: Effects of previous tobacco consumption, and depression and anxiety symptoms

OBJECTIVE

Previous tobacco consumption, and depression and anxiety symptoms are major predictors of women's tobacco consumption during pregnancy and the postpartum period. However, the joint effect of these predictors is still unexplored. This study aimed to analyse the effects of previous tobacco consumption, and depression and anxiety symptoms on women's tobacco consumption status and quantity from the 1st trimester of pregnancy to 7 months postpartum.

METHOD

A sample of 803 Spanish women was assessed at the 1st and the 3rd trimester of pregnancy, and at 2 and 7 months postpartum. Previous tobacco consumption, and depression and anxiety symptoms were self-reported. Pregnancy and postpartum tobacco consumption were confirmed with biochemical tests.

RESULTS

Women with more previous tobacco consumption or more anxiety symptoms presented a steeper decrease in the number of cigarettes smoked per week from the 1st trimester of pregnancy to the childbirth, although smoking more cigarettes than women with less previous tobacco consumption or less anxiety symptoms. Women with more depression symptoms showed a higher tendency to relapse smoking during the first 2 months postpartum.

CONCLUSIONS

Previous tobacco consumption and anxiety symptoms were associated with higher smoking quantity during pregnancy, while depression symptoms were associated with consumption relapse during postpartum period.

Central Australian Aboriginal women's placental and neonatal outcomes following maternal smokeless tobacco, cigarette or no tobacco use

OBJECTIVE

To describe the placental characteristics and neonatal outcomes of Central Australian Aboriginal women based on maternal self-report of tobacco use.

METHODS

Placental and neonatal variables were collected from a prospective maternal cohort of 19 smokeless tobacco chewers, 23 smokers and 31 no-tobacco users.

RESULTS

Chewers had the lowest placental weight (460 g) while the no-tobacco group had the heaviest placental weight (565 g). Chewers and the no-tobacco group had placental areas of similar size (285 cm² and 288 cm² , respectively) while the placentas of smokers were at least 13 cm² smaller (272 cm² ). There were two stillbirths in the study and more than one-third (36%) of neonates (newborns) were admitted to the Special Care Nursery, with the chewers' neonates having a higher admission rate compared with smokers' neonates (44% vs. 23%). The cohort mean birthweight (3348 g) was not significantly different between the groups. When stratified for elevated maternal glucose, the chewers' neonates had the lowest mean birthweight (2906 g) compared to the neonates of the no-tobacco group (3242 g) and smokers (3398 g).

CONCLUSIONS

This research is the first to demonstrate that the maternal use of Australian Nicotiana spp. (pituri) as smokeless tobacco may negatively impact placental and neonatal outcomes. Implications for public health: Maternal smokeless tobacco use is a potential source of placental and foetal nicotine exposure. Maternal antenatal screening should be expanded to capture a broader range of tobacco and nicotine products, and appropriate cessation support is required.

The risk factors associated with placenta previa: An umbrella review

We evaluated in this umbrella review a systematic collection from meta-analyses conducted on risk factors associated with placenta previa. We searched PubMed, Scopus, and Web of Science until April 2021 assessing the risk factors associated with placenta previa. We calculated summary effect estimates odds ratio, relative risk, 95% CI, heterogeneity I², 95% prediction interval, small-study effects, excess significance biases, and sensitive analysis. The quality of the meta-analyses was evaluated with AMSTAR 2. We included nine studies in the present umbrella review. Seven risk factors including prior induced abortion (OR 1·36, 95% CI: 1·02, 1·69), prior spontaneous abortion (OR 1·77, 95% CI: 1·60, 1·94), male fetus (OR 1·2, 95% CI: 1·2, 1·3), smoking (OR 1·42, 95% CI 1·30, 1·54) (RR 1·27, 95% CI: 1·18, 1·35) advanced maternal age (OR 3·16, 95% CI: 2·79, 3·57), cesarean (OR 1·60, 95% CI: 1·44, 1·76) and ART (singleton pregnancy) (RR 3·71, 95% CI: 2·67, 5·16) were graded as highly suggestive evidence (class III). Endometriosis (OR 3·03, 95% CI: 1·50, 6·13) and maternal cocaine use (OR 2·9, 95% CI: 1·9, 4·3) were graded as risk factors with weak evidence (class IV). This study provides suggestive evidence about prior spontaneous abortion, prior induced abortion, male fetus, smoking, advanced maternal age, cesarean section, and assisted reproductive techniques (singleton pregnancy) as risk factors associated with placenta previa.

Effects of active and/or passive smoking during pregnancy and the postpartum period

INTRODUCTION

Tobacco smoking may cause adverse effects during pregnancy and postpartum. The aim of this study was to evaluate several repercussions of active and/or passive smoking by the mother at home, during pregnancy, at delivery, as well as for the newborn baby and breastfeeding, including the effect of quitting smoking in the first trimester of pregnancy.

METHODS

A prospective longitudinal study was carried out with a sample of 800 pregnant women. Four evaluations were made: first and third trimester of pregnancy, and 2 and 6/8 months postpartum. Sociodemographic, obstetric, health and tobacco consumption details were collected, with biochemical tests being performed to confirm the self-reported abstinence.

RESULTS

Being an active and passive smoker predicted suffering complications in pregnancy (OR 2.50; 95% CI; 1.42-4.35) and delivery (OR 3.10; 95% CI; 1.75-5.51), and also tended not to breastfeed (OR 2.44; 95% CI; 1.35-4.42). Being an active smoker predicted complications at childbirth (OR 5.58; 95% CI; 2.64-7.77), for the baby (OR 3.77; 95% CI; 1.53-9.36) and not breastfeeding at 2 (OR 25.73; 95% CI; 11.95-55.40), and 6/8 months postpartum (OR 6.61; 95% CI; 3.21-13.58). Being a passive smoker reduces the intend to breastfeed (OR 1.81; 95% CI; 1.11-2.95), and the practice of breastfeeding at 2 months postpartum (OR 1.94; 95% CI; 1.11-3.37). Women who quit smoking are less likely to suffer complications in pregnancy and childbirth, and are more likely to attend antenatal and breastfeeding classes, and to have babies with higher birth weight.

CONCLUSIONS

Active and passive tobacco consumption has significant implications during pregnancy and postpartum period. Smoking cessation at the beginning of pregnancy reverses much of these effects.

Decreased head circumference at birth associated with maternal tobacco smoke exposure during pregnancy on the Japanese prospective birth cohort study

Maternal tobacco smoke exposure during pregnancy impairs fetal body size, including head circumference (HC) at birth; however, the mechanism still remains unclear. This analysis using a large prospective cohort study evaluated the impact of maternal tobacco exposure on their offspring's HC and the relationship with placental weight ratio (PWR) and placental abnormalities. Parents-children pairs (n = 84,856) were included from the 104,065 records of the Japan Environmental and Children's Study. Maternal perinatal clinical and social information by self-administered questionnaires, offspring's body size, and placental information were collected. Data were analyzed with binominal logistic regression analysis and path analysis. Logistic regression showed significantly elevated adjusted odds ratio (aOR) (1.653, 95% CI 1.387-1.969) for the impact of maternal smoking during pregnancy on their offspring's smaller HC at birth. Maternal exposure to environmental tobacco smoke in the non-smoking group did not increase aOR for the smaller HC. Path analysis showed that maternal smoking during pregnancy decreased the offspring's HC directly, but not indirectly via PWR or placental abnormalities. The quitting smoking during pregnancy group did not increase aOR for the smaller HC than the non-smoking group, suggesting that quitting smoking may reduce their offspring's neurological impairment even after pregnancy.

Trends of maternal waterpipe, cigarettes, and dual tobacco smoking in Jordan. A decade of lost opportunities

Background

Maternal tobacco use is a global public health problem. In the literature, the focus was mainly on cigarette smoking, minimally on waterpipe use, and totally ignored dual use among pregnant women. We estimated the prevalence of current maternal tobacco use by tobacco product (cigarette, waterpipe, and dual use) over a period of ten years (2007 to 2017), and examined the socio-demographic patterning of maternal tobacco use.

Methods

A secondary analysis of Jordan DHS four data waves was conducted for women who reported to be pregnant at the time of the survey. Current cigarette and waterpipe tobacco use were investigated. Prevalence estimates for cigarette-only, waterpipe-only, and dual use, as well as for cigarette, regardless of waterpipe, and waterpipe, regardless of cigarette, were reported. The effect of independent variables on cigarette smoking, waterpipe use, and dual use was assessed. Logistic regression models assessed the adjusted effects of socio-demographic variables on cigarette smoking, waterpipe use, and on dual use. For each outcome variable, a time-adjusted and a time-unadjusted logistic models were conducted.

Results

Over the last decade, the prevalence estimates of current cigarette-only smoking slightly decreased. The prevalence estimates of current waterpipe-only use exceeded those for cigarette-only after 2007 and showed a steady overall increase. Current dual use showed a continuous rise especially after 2009. Gradual increase in cigarette smoking (4.1%, in 2007, and 5.7% in 2017) and in waterpipe use (2.5% to 6.4%) were detected. Education showed an inverse relationship with cigarette and waterpipe smoking. Household wealth demonstrated a positive association with cigarette and waterpipe smoking.

Conclusions

Tobacco use epidemic is expanding its roots among pregnant women in Jordan through not only waterpipe use but also dual cigarette–waterpipe smoking. Maternal and child services should consider tobacco counseling and cessation.

Maternal and neonatal outcomes in transverse and vertical skin incision for placenta previa : Skin incision for placenta previa

BACKGROUND

Placenta previa, a serious obstetric issue, should be managed by experienced teams. The safe and appropriate mode of delivery for placenta previa is by cesarean delivery. However, no studies were found comparing either maternal or neonatal outcomes for different skin incision in women with placenta previa. The aim of this study was to compare maternal and neonatal outcomes by skin incision types (transverse compared with vertical) in a large cohort of women with placenta previa who were undergoing cesarean delivery.

METHODS

This was a retrospective cohort study carried out between January 2014 and June 2019. All pregnant women with placenta previa had confirmed by ultrasonologist before delivery and obstetrician at delivery. The primary outcome was the estimated blood loss during the surgery and within the first 24 hours postoperatively. Mean (standard deviation), median (interquartile range) or frequency (percentage) was reported to variables. Appropriate parametric and nonparametric tests were used to analyses.

RESULTS

The study included 1098 complete records, 332 (30.24%) cases in the vertical skin incision group and 766 (69.76%) cases in the transverse skin incision group. Those with vertical incision showed a higher percentage of preterm delivery, anterior placenta, abnormally invasive placenta, and history of previous cesarean delivery, and a lower percentage of first pregnancy, in vitro fertilization, and emergency cesarean delivery. After controlling for confounding factors, higher incidence of post-partum hemorrhage (OR 5.47, 95% CI 3.84-7.79), maternal intensive care unit (OR 4.30, 95% CI 2.86-6.45), transfusion (OR 5.97, 95% CI 4.15-8.58), and 5-min APGAR< 7 (OR 9.03, 95% CI 1.83-44.49), a more estimated blood loss (β 601.85, 95%CI 458.78-744.91), and a longer length of hospital stay after delivery (β 0.54, 95%CI 0.23-0.86) were found in the vertical skin incision group.

CONCLUSIONS

Our data demonstrated that transverse skin incision group showed the better perinatal outcomes in women with placenta previa. Future collaborative studies are needed to be done by centers for placenta previa to have a better understanding of the characteristics and the outcomes of the disease in the choosing skin incision.

Tobacco dependence treatment for special populations: challenges and opportunities

Although smoking rates have declined in most of the countries in the world, there are population groups within these countries whose smoking rates remain significantly higher than the general population. These "forgotten groups" who have not been receiving the needed attention in tobacco control policies and tobacco cessation efforts include people with serious mental illness, substance use disorders, tuberculosis, people living with human immunodeficiency virus (HIV), lesbian-gay-bisexual-transgender-queer people, and pregnant women. A number of steps are needed at the national level in countries where these disparities exist, including modifications to national smoking cessation treatment guidelines that address the special needs of these populations, as well as targeted smoking cessation research, since these populations are often not included in clinical trials. Because of the higher smoking prevalence in these populations, as well as their lower smoking cessation treatment success rates than the general population, more resources are needed if we are to reduce health disparities in these vulnerable populations. Additionally, we believe that more effort should be focused on integrating smoking cessation treatment in the specialized care settings frequented by these subpopulations.

Immunohistochemical Expression of the Alpha Nicotinic Acetylcholine Receptor 7 in the Human Normal, Diabetic, and Preeclamptic Placenta and Products of Conception

Preeclampsia (PE) and gestational diabetes (GD) are complications in advanced pregnancy while miscarriage for early pregnancy. However, the etiological factors are not well understood. Smoking has been associated with these complications as well as the sudden intrauterine deaths, sudden infant death, miscarriages, and still births. However, the immunolocalization of alpha 7 nicotine acetylcholine receptor (α7-nAChR) is not studied. Materials and Methods: α7-nAChR subunit expression was evaluated in 10 paraffin-embedded placental tissues after delivery and 10 tissue samples of products of conception during first trimester by immunohistochemistry. Among the placental tissues, two samples were normal placental tissue, four from PE mother, and four from GD mother. The expression of α7-nAChR was compared between the two groups in general and within the subgroups of placenta as well. Protein expression was evaluated using the nuclear labeling index (%) of villi with positive cells stained, positive cells in the decidua, and intensity of staining in the outer villous trophoblast layer. Results: The expression of α7-nAChR protein was high in all the cases of placenta and products of conception (POCs). α7-nAChR expression showed no notable differences among different cases of miscarriages irrespective of the mother's age and gestational age at which the event occurred. However, there were some changes among the normal, PE, and GD placental groups in the linings of the blood vessels. Changes were restricted to the villi (as opposed to the decidua) lining cells, both cytotrophoblast and syncytiotrophoblast, and were specific to the α7 subunit. PE blood vessel lining was thicker and showed more expression of this receptor in endothelial cells and myofibroblasts in PE and GD groups. In POCs, the strong expression was observed in the decidua myocytes of maternal blood vessels and in syncytiotrophoblast and cytotrophoblast of chronic villi. Conclusion: Nicotine acetyl choline receptors are found to be expressed highly in the placental tissues and in products of conception. They may be associated with the sudden perinatal deaths and miscarriages or complications of pregnancy.

Effects of Tobacco Consumption and Anxiety or Depression during Pregnancy on Maternal and Neonatal Health

This study analyzed the possible interaction effects between tobacco consumption and anxiety or depression during pregnancy on maternal and neonatal health. We recruited a sample of 807 pregnant Spanish women from public healthcare services. Women completed a questionnaire on sociodemographic variables, health status and tobacco consumption (continuous, quitting or no consumption) in the first and third trimester of pregnancy and at 2 months postpartum, and self-reported measures of anxiety and depression in the first trimester. Abstinence of tobacco consumption was verified through biochemical measurements. Interaction effects between tobacco consumption and anxiety were found for delivery (p < 0.001), neonatal health complications (p = 0.026) and gestational age at birth (p = 0.029). Interaction effects between tobacco consumption and depression were found for pregnancy (p = 0.032), delivery complications (p < 0.001) and weeks of gestation at birth (p = 0.031). This study suggests that there are different kinds of interaction effects between tobacco consumption and anxiety or depression. Smokers with high anxiety presented more delivery complications compared to quitters and non-smokers with high anxiety. There is a cumulative effect of anxiety on the effects of tobacco consumption on maternal health. The results highlighted the beneficial impact of quitting smoking during pregnancy to reduce the risk of suffering anxiety, depression and health complications.

Early Life Exposure to Nicotine: Postnatal Metabolic, Neurobehavioral and Respiratory Outcomes and the Development of Childhood Cancers

Cigarette smoking during pregnancy is associated with numerous obstetrical, fetal, and developmental complications, as well as an increased risk of adverse health consequences in the adult offspring. Nicotine replacement therapy and electronic nicotine delivery systems (e-cigarettes) have been developed as a pharmacotherapy for smoking cessation and are considered safer alternatives for women to smoke during pregnancy. The safety of nicotine replacement therapy use during pregnancy has been evaluated in a limited number of short-term human trials, but there is currently no information on the long-term effects of developmental nicotine exposure in humans. However, animal studies suggest that nicotine alone may be a key chemical responsible for many of the long-term effects associated with maternal cigarette smoking on the offspring and increases the risk of adverse neurobehavioral outcomes, dysmetabolism, respiratory illness, and cancer. This review will examine the long-term effects of fetal and neonatal nicotine exposure on postnatal health.

[Effects of active and/or passive smoking during pregnancy and the postpartum period]

INTRODUCTION

Tobacco smoking may cause adverse effects during pregnancy and postpartum. The aim of this study was to evaluate several repercussions of active and/or passive smoking by the mother at home, during pregnancy, at delivery, as well as for the new born baby and breastfeeding, including the effect of quitting smoking in the first trimester of pregnancy.

METHODS

A prospective longitudinal study was carried out with a sample of 800 pregnant women. Four evaluations were made: first and third trimester of pregnancy, and 2 and 6/8 months postpartum. Sociodemographic, obstetric, health and tobacco consumption information was collected, with biochemical tests being performed to confirm the self-reported abstinence.

RESULTS

Being an active and passive smoker predicted suffering complications in pregnancy (OR 2.50; 95% CI; 1.42-4.35) and delivery (OR 3.10; 95% CI; 1.75-5.51), and also intend not to breastfeed (OR 2.44; 95% CI; 1.35-4.42). Being an active smoker predicted complications at childbirth (OR 5.58; 95% CI; 2.64-7.77), for the baby (OR 3.77; 95% CI; 1.53-9.36) and not breastfeeding at 2 (OR 25.73; 95% CI; 11.95-55.40), and 6/8 months postpartum (OR 6.61; 95% CI; 3.21-13.58). Being a passive smoker reduces the intention to breastfeed (OR 1.81; 95% CI; 1.11-2.95), and the practice of breastfeeding at 2 months postpartum (OR 1.94; 95% CI; 1.11-3.37). Women who quit smoking are less likely to suffer complications in pregnancy and childbirth, and are more likely to attend antenatal and breastfeeding classes, and to have babies with higher birth weight.

CONCLUSIONS

Active and passive tobacco consumption has significant implications during pregnancy and postpartum period. Smoking cessation at the beginning of pregnancy reverses much of these effects.

[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.

Exposure to Tobacco, Environmental Tobacco Smoke and Nicotine in Pregnancy: A Pragmatic Overview of Reviews of Maternal and Child Outcomes, Effectiveness of Interventions and Barriers and Facilitators to Quitting

The aim of this review of reviews was to collate the latest evidence from systematic reviews about the maternal and child health outcomes of being exposed to tobacco and nicotine during pregnancy; the effectiveness of interventions designed to reduce these exposures, and barriers to and facilitators of smoking cessation during pregnancy. Two databases were searched to obtain systematic reviews published from 2010 to 2019. Pertinent data from 76 articles were summarized using a narrative synthesis (PROSPERO reference: CRD42018085896). Exposure to smoke or tobacco in other forms during pregnancy is associated with an increased risk of obstetric complications and adverse health outcomes for children exposed in-utero. Counselling interventions are modestly effective, while incentive-based interventions appear to substantially increase smoking cessation. Nicotine replacement therapy is effective during pregnancy but the evidence is not conclusive. Predictors and barriers to smoking cessation in pregnancy are also discussed. Smoking during pregnancy poses substantial risk to mother's and child's health. Psychosocial interventions and nicotine replacement therapy (NRT) appear to be effective in helping pregnant women quit smoking. Barriers to smoking cessation must be identified and steps taken to eradicate them in order to reduce smoking among pregnant women. More research is needed on smoking cessation medications and e-cigarettes.

Development of placental abnormalities in location and anatomy

Low‐lying placentas, placenta previa and abnormally invasive placentas are the most frequently occurring placental abnormalities in location and anatomy. These conditions can have serious consequences for mother and fetus mainly due to excessive blood loss before, during or after delivery. The incidence of such abnormalities is increasing, but treatment options and preventive strategies are limited. Therefore, it is crucial to understand the etiology of placental abnormalities in location and anatomy. Placental formation already starts at implantation and therefore disorders during implantation may cause these abnormalities. Understanding of the normal placental structure and development is essential to comprehend the etiology of placental abnormalities in location and anatomy, to diagnose the affected women and to guide future research for treatment and preventive strategies. We reviewed the literature on the structure and development of the normal placenta and the placental development resulting in low‐lying placentas, placenta previa and abnormally invasive placentas.

Systematic review with meta-analysis: risk of adverse pregnancy-related outcomes in inflammatory bowel disease

BACKGROUND

The effect of inflammatory bowel disease (IBD) on pregnancy-related outcomes remains unknown.

AIM

To determine the risk of adverse maternal, placental and obstetric outcomes in IBD METHODS: We searched Medline, Embase and Cochrane library through May 2019 for studies reporting adverse maternal, placental and obstetric outcomes in patients with IBD. Odds ratios (OR) with 95% confidence intervals (CI) were calculated for these outcomes in patients with IBD compared to healthy controls.

RESULTS

Fifty-three studies were included (7917 IBD pregnancies and 3253 healthy control pregnancies). Caesarean delivery was more common in patients with IBD compared to healthy controls (OR 1.79, 95% CI, 1.16-2.77). This remained significant for UC (OR 1.80, 95% CI, 1.21-2.90) but not CD (OR 1.48, 95% CI, 0.94-2.34). Similarly, gestational diabetes occurred more commonly in IBD (OR 2.96, 95% CI, 1.47-5.98). The incidences of placental diseases were 2.0% (95% CI, 0.9%-3.1%) for pre-eclampsia, 3.3% (95% CI, 0%-7.2%) for placental abruption, 0.5% (95% CI, 0.2%-0.9%) for placenta previa and 0.3% (95% CI, 0%-0.5%) for chorioamnionitis. Patients with IBD were more likely to experience preterm prelabour rupture of membranes (OR 12.10, 95% CI, 2.15-67.98), but not early pregnancy loss (OR 1.63, 95% CI 0.49-5.43). Anti-tumour necrosis factor therapy was not associated with chorioamnionitis (OR 1.12, 95% CI, 0.16-7.67), early pregnancy loss (OR 1.49, 95% CI, 0.83-2.64) or placenta previa (OR 1.58, 95% CI, 0.30-8.47).

CONCLUSIONS

Gestational diabetes and preterm prelabour rupture of membranes occurs more commonly in patients with IBD, although the incidence of placental diseases remains low.

Nicotine Suppresses the Invasiveness of Human Trophoblasts by Downregulation of CXCL12 Expression through the Alpha-7 Subunit of the Nicotinic Acetylcholine Receptor

Smoke exposure during pregnancy has detrimental effects upon numerous fetal and neonatal outcomes. Nicotine (the main component of tobacco) has been suggested to affect placental development. During placental development, efficient invasion by trophoblasts is required for establishment of the fetus–maternal circulation. In this study we explored the regulation of trophoblast invasion by nicotine. An immortalized first trimester extravillous trophoblast cell line (HTR-8/SVneo cells) was used for all the experiments, which were treated by nicotine, methyllycaconitine, and C-X-C motif chemokine ligand 12 (CXCL12). Total RNA and protein were used to study the expressions of nicotinic acetylcholine receptors (nAChRs), and transwell assay was used to study invasiveness. Changes of RNA expression due to nicotine treatment were detected by RNA sequence. Level of CXCL12 mRNA was verified by quantitative PCR. We showed that HTR-8/SVneo expressed subunits α2–4, α7, α9, β1, and β2 of nAChRs. Nicotine downregulated CXCL12 expression and inhibited trophoblast invasion. Methyllycaconitine, as an antagonist of the α7 homopolymer, blocked the inhibitory effect of nicotine. CXCL12 could rescue the nicotine-induced inhibitory effect on invasion of HTR-8/SVneo cells. These results suggest that the α7 subunit of the nAChR has important roles in modulating trophoblast invasion through CXCL12.

Placental Implantation Disorders

Primary disorders of placental implantation have immediate consequences for the outcome of a pregnancy. These disorders have been known to clinical science for more than a century, but have been relatively rare. Recent epidemiologic obstetric data have indicated that the rise in their incidence over the last 2 decades has been iatrogenic in origin. In particular, the rising numbers of pregnancies resulting from in vitro fertilization (IVF) and the increased use of caesarean section for delivery have been associated with higher frequencies of previa implantation, accreta placentation, abnormal placental shapes, and velamentous cord insertion. These disorders often occur together.

Associations between metal concentrations in whole blood and placenta previa and placenta accreta: the Japan Environment and Children's Study (JECS)

Background

Placenta previa and placenta accreta associate with high morbidity and mortality for both mothers and fetus. Metal exposure may have relationships with placenta previa and placenta accreta. This study analyzed the associations between maternal metal (cadmium [Cd], lead [Pb], mercury [Hg], selenium [Se], and manganese [Mn]) concentrations and placenta previa and placenta accreta.

Methods

We recruited 17,414 women with singleton pregnancies. Data from a self-administered questionnaire regarding the first trimester and medical records after delivery were analyzed. Maternal blood samples were collected to measure metal concentrations. The subjects were classified into four quartiles (Q1, Q2, Q3, and Q4) according to metal concentrations.

Results

The odds ratio for placenta previa was significantly higher among subjects with Q4 Cd than those with Q1 Cd. The odds ratio for placenta previa was significantly higher for subjects with Q2 Pb than those with Q1 Pb.

Conclusion

Participants with placenta previa had higher Cd concentrations. However, this study was cross-sectional and lacked important information related to Cd concentration, such as detailed smoking habits and sources of Cd intake. In addition, the subjects in this study comprised ordinary pregnant Japanese women, and it was impossible to observe the relationship between a wide range of Cd exposure and placenta previa. Therefore, epidemiological and experimental studies are warranted to verify the relationship between Cd exposure and pregnancy abnormalities.

Electronic supplementary material

The online version of this article (10.1186/s12199-019-0795-7) contains supplementary material, which is available to authorized users.

Influence of Active Exposure to Tobacco Smoke on Nitric Oxide Status of Pregnant Women

Smoking tobacco can impair proper vascular endothelial functioning. This is exhibited through reduced nitric oxide synthesis as well as activity due to accompanying oxidative stress. We examined the relationship between nitric oxide and markers of oxidative stress/antioxidant defense in serum of smoking and non-smoking pregnant women. Subjects included 99 healthy pregnant women, who were tested for nitric oxide (NO), endothelial (eNOS) and inducible (iNOS) nitric oxide synthase, total oxidant capacity (TOC), and total antioxidant capacity (TAC). NO, eNOS, and TAC serum concentrations were significantly lower (p < 0.005), but iNOS (p < 0.05) and TOC (p < 0.001) were higher in smokers than in non-smokers. Multivariate regression analysis showed associations between NO concentration and eNOS, TAC, and smoking status in the whole group of patients. In the model estimated separately for smokers, the highest impact of eNOS (β = 0.375; p = 0.021) and cotinine (β = −0.323; p = 0.037) was indicated for NO concentration. In the model of non-smokers, eNOS (β = 0.291, p = 0.030) and TAC (β = 0.350; p = 0.015) were important for NO level. Smoking during pregnancy could exacerbate oxidative stress, impair the action of nitric oxide synthases, and adversely affect the balance of oxygen and nitrogen metabolism. Relationships between NO concentrations and TAC in the studied women’s blood can confirm the antioxidant nature of nitric oxide.

The uterine leiomyoma and placenta previa: a meta-analysis

Background: Some epidemiological studies have reported that uterine leiomyoma may increase the risk of placenta previa. To date, the meta-analysis has not been carried out for assessing the relationship between uterine leiomyoma and placenta previa. This meta-analysis was carried out to estimate the association between uterine leiomyoma and the risk of placenta previa. Methods: A systematic search was conducted out in major databases PubMed, Web of Science, and Scopus from the earliest possible year to June 2017. The heterogeneity across studies was explored by Q-test and I² statistic. The publication bias was assessed by Begg's and Egger's tests. The results were showed using odds ratio (OR) estimate with its 95% confidence intervals (CI) using a random-effects model. Results: The literature search included 1218 articles until to June 2017 with 255,886 women. Based on OR estimates obtained from case-control and cohort studies, there was significant association between uterine leiomyoma and placenta previa in studies adjusted (2.21; 95%CI: 1.48, 2.94). Conclusions: We showed based on reports in observational studies that uterine leiomyoma is a risk factor for placenta previa in studies adjusted.