Smoking cessation in the first trimester reduces most obstetric risks, but not the risks of major congenital anomalies and admission to neonatal care: a population-based cohort study of 1 164 953 singleton pregnancies in Finland

Maternal cigarette smoking before or during pregnancy increases the risk of severe neonatal morbidity after delivery: a nationwide population-based retrospective cohort study

BACKGROUND

The association of maternal cigarette smoking during pregnancy with severe neonatal morbidity (SNM) is still inconclusive. We aimed to examine the associations of the timing and the intensity of maternal cigarette smoking with infant SNM in the USA.

METHODS

We used birth certificate data of 12 150 535 women aged 18-49 years who had live singleton births from the 2016-2019 US National Vital Statistics System. Women self-reported the daily number of cigarettes they consumed before pregnancy and in each trimester of pregnancy. Composite SNM was defined as one or more of the following complications: assisted ventilation immediately following delivery, assisted ventilation for >6 hours, neonatal intensive care unit admission, surfactant replacement therapy, suspected neonatal sepsis, and seizure.

RESULTS

Maternal cigarette smoking either before pregnancy or during any trimester of pregnancy significantly increased the risk of infant SNM, even at a very low intensity (ie, 1-2 cigarettes per day). For example, compared with women who did not smoke before pregnancy, the adjusted odds ratios and 95% confidence intervals (OR, 95% CI) of composite SNM in the newborn from women who smoked 1-2, 3-5, 6-9, 10-19, and ≥20 cigarettes per day before pregnancy were 1.16 (1.13 to 1.19), 1.22 (1.20 to 1.24), 1.26 (1.23 to 1.29), 1.27 (1.25 to 1.28), and 1.31 (1.30 to 1.33), respectively. Furthermore, smokers who stopped smoking during pregnancy still had a higher risk of composite SNM than never smokers before and throughout pregnancy.

CONCLUSIONS

Maternal cigarette smoking before or during pregnancy increased the risk of infant SNM, even at a low dose of 1-2 cigarettes/day. Interventions should emphasise the detrimental effects of even light smoking before and during pregnancy.

Maternal smoking cessation in the first trimester still poses an increased risk of attention-deficit/hyperactivity disorder and learning disability in offspring

Background

Studies have found maternal smoking during pregnancy was linked to attention-deficit/hyperactivity disorder (ADHD) risk. It is unclear if maternal smoking cessation during pregnancy lowers ADHD and learning disability (LD) risk in offspring. This study aimed to explore the associations between maternal smoking cessation during pregnancy and ADHD and LD risk in offspring.

Methods

Data from the National Health and Nutrition Examination Survey 1999-2004 (8,068 participants) were used. Logistic regression was used to analyze the associations between maternal smoking and smoking cessation during pregnancy and ADHD and LD risk in offspring.

Results

Compared to non-smokers' offspring, maternal smoking during pregnancy increased the risk of ADHD (odds ratios [OR] = 2.07, 95% confidence interval [CI]: 1.67-2.56) and LD (OR = 1.93, 95% CI: 1.61-2.31) in offspring, even if mothers quit smoking later (ORADHD = 1.91, 95%CIADHD: 1.38-2.65, ORLD = 1.65, 95%CILD: 1.24-2.19). Further analysis of the timing of initiation of smoking cessation during pregnancy revealed that, compared to non-smokers' offspring, maternal quitting smoking in the first trimester still posed an increased risk of ADHD (OR = 1.72, 95% CI: 1.41-2.61) and LD (OR = 1.52, 95% CI: 1.06-2.17) in offspring. Maternal quitting smoking in the second or third trimester also had a significantly increased risk of ADHD (OR = 2.13, 95% CI: 1.26-3.61) and LD (OR = 1.82, 95% CI: 1.16-2.87) in offspring. Furthermore, maternal smoking but never quitting during pregnancy had the highest risk of ADHD (OR = 2.17, 95% CI: 1.69-2.79) and LD (OR = 2.10, 95% CI: 1.70-2.58) in offspring. Interestingly, a trend toward a gradual increase in the risk-adjusted OR for ADHD and LD risk was observed among the three groups: maternal quitting smoking in the first trimester, maternal quitting smoking in the second or third trimester, and maternal smoking but never quitting.

Conclusion

Maternal smoking cessation in the first trimester still poses an increased risk of ADHD and LD in offspring. Furthermore, it seems that the later the mothers quit smoking during pregnancy, the higher the risk of ADHD and LD in their offspring. Therefore, early intervention of maternal smoking in preconception and prenatal care is vital for offspring neurodevelopment.

Association between maternal cigarette smoking cessation and risk of preterm birth in Western New York

BACKGROUND

Although many studies suggested the benefit of smoking cessation among pregnant women in reducing the risk of preterm birth (PTB), the timing of the effect of the cessation remains inconclusive.

OBJECTIVES

To examine the association of trimester-specific smoking cessation behaviours with PTB risk.

METHODS

We included 199,453 live births in Western New York between 2004 and 2018. Based on self-reported cigarette smoking during preconception and in each trimester, we created six mutually exclusive groups: non-smokers, quitters in each trimester, those who smoked throughout pregnancy, and inconsistent smokers. Risk ratios (RRs) and 95% confidence intervals (CIs) were estimated using Poisson regression to examine the association between smoking cessation and PTB. Effect modification by illegal drug use, maternal age, race and ethnicity and pre-pregnancy body mass index (BMI) was investigated multiplicatively by ratio of relative risk and additively by relative excess risk due to interaction (RERI).

RESULTS

Overall, 6.7% of women had a PTB; 14.1% smoked throughout pregnancy and 3.4%, 1.8% and 0.8% reported quitting smoking during the first, second and third trimesters, respectively. Compared to non-smokers, third-trimester cessation (RR 1.20, 95% CI 1.01, 1.43) and smoking throughout pregnancy (RR 1.27, 95% CI 1.21, 1.33) were associated with a higher PTB risk, while quitting smoking during the first or second trimester, or inconsistent smoking was not associated with PTB. A positive additive interaction was identified for maternal age and late smoking cessation or smoking throughout pregnancy on PTB risk (RERI 0.17, 95% CI 0.00, 0.36), and a negative interaction was observed for pre-pregnancy BMI ≥30 kg/m2 (ratio of relative risk 0.70, 95% CI 0.63, 0.78; RERI -0.42, 95% CI -0.56, -0.30).

CONCLUSION

Compared to non-smokers, smoking throughout pregnancy and third-trimester smoking cessation are associated with an increased risk of PTB, while quitting before the third trimester may not increase PTB risk.

Are reduced fetal movements "merely" a maternal perception or truly a reflection of umbilical cord complications? A clinical trial

OBJECTIVE

To characterize obstetric outcomes and the association with umbilical cord (UC) complications among women complaining of reduced fetal movements (RFMs).

METHODS

This retrospective cohort compared women with a perception of RFMs within 2 weeks prior to delivery with women who reported no changes in fetal movements in terms of maternal characteristics and neonatal outcomes. A primary outcome of UC complications at delivery was defined. Multivariable regression analysis was performed to identify independent associations with RFMs and UC complications.

RESULTS

In all, 46 103 women were included, 2591 (5.6%) of whom reported RFMs and 43 512 (94.4%) in the control group. Compared with controls, the RFM group was more likely to be nulliparous (42.6% vs 32.2%, P < 0.001), smokers (6.4% vs 5.4%, P = 0.029), or obese (body mass index >30) (16.4% vs 11.6%, P < 0.001). They were also more likely to have an anterior placenta (56.2% vs 51.8%, P < 0.001) and poly/oligohydramnios (0.7% vs 0.4%, P = 0.015 and 3.6% vs 2.1%, P < 0.001, respectively). Induction of labor was more common in the RFM group (33.9% vs 19.7%, P < 0.001), as well as meconium (16.8% vs 15.0%, P = 0.026) and vacuum extractions (10.1% vs 8.0%, P < 0.001). Higher rates of stillbirth and the severe composite neonatal outcome were observed in the RFM group (1.5% vs 0.2%, P < 0.001 and 0.6% vs 0.3%, P = 0.010, respectively). The RFM group was characterized by higher rates of triple nuchal cord (P = 0.015), UC around body or neck (32.2% vs 29.6%, P = 0.010), and true knot (2.3% vs 1.4%, P = 0.002). Multivariable logistic regression found RFMs to be independently associated with triple nuchal cord and with a true cord knot. A sub-analysis including only cases of stillbirth (n = 127) revealed even higher rates of UC complications: 7% of all stillbirths presented with a true cord knot (20% true knots were found in stillbirths preceded by RFMs vs 6.1% in stillbirth cases without RFMs). Additionally, 33.8% of all stillbirths presented with nuchal cord (40% preceded by RFMs vs 33.3% without RFMs).

CONCLUSIONS

RFMs are associated with increased risk of UC complications observed at delivery, as well as increased risk of stillbirth and neonatal adverse outcomes.

Maternal smoking during pregnancy links to childhood blood pressure through birth weight and body mass index: NHANES 1999-2018

Maternal smoking during pregnancy (MSDP) is associated with lower birth weight, childhood obesity, and elevated blood pressure (BP) in offspring. We aimed to examine whether birth weight and body mass index (BMI) mediate the effect of MSDP on BP in children. The study included 14,713 children aged 8 to 15 years from the National Health and Nutrition Examination Surveys from 1999 to 2018. General third-variable models were used to examine the mediating effects of birth weight and BMI on the association of MSDP with BP. A total of 1928 (13.1%) children were exposed to MSDP. MSDP was associated with reduced birth weight (p < 0.001), increased BMI (p < 0.001), and elevated systolic BP (p = 0.005). MSDP was not associated with systolic BP after adjustment for birth weight and BMI z-score (p = 0.875), with 95.0% of the effect of MSDP on BP mediated by birth weight (39.1%) and BMI (55.9%). In conclusion, lower birth weight and increased obesity measures mediate the adverse effects of MSDP on BP in children. These findings provide novel mechanistic insight into the adverse effect of MSDP on BP in children and have implications for preventing hypertension in later life.

Are Babies Born Preterm High-Risk Asthma Candidates?

Among preterm infants, the risk of developing asthma is a matter of debate. This review discusses the state of the art of poorly understood prematurity-associated asthma. Impaired pulmonary function is common in children born prematurely. Preterm infants are prone to developing viral respiratory tract infections, bronchiolitis in the first year of life, and recurrent viral wheezing in preschool age. All of these conditions may precede asthma development. We also discuss the role of both atopic sensitization and intestinal microbiome and, consequently, immune maturation. Diet and pollution have been considered to better understand how prematurity could be associated with asthma. Understanding the effect of factors involved in asthma onset may pave the way to improve the prediction of this asthma phenotype.

Active or passive maternal smoking increases the risk of low birth weight or preterm delivery: Benefits of cessation and tobacco control policies

In France, maternal smoking, active or passive, remains one of the highest in Europe. At the same time, there is an increase in the number of low birth weight (<2500 g) and premature (<37 weeks of amenorrhea) newborns. The objective of this narrative review is to examine the impact of active or passive maternal smoking on birth weight or prematurity rates, and to consider the benefits of policies to stop or control smoking. This is a narrative review that analyzes and discusses the major articles published over the past 20 years regarding the role of active or passive maternal smoking on the risk of low birth weight or preterm delivery. Articles were selected using the following keywords: maternal smoking, low birth weight, preterm birth, smoking cessation, passive smoking, exhaled carbon monoxide, tobacco control policies. Active smoking is associated, in a dose-response relationship, with increased risks of low birth weight and preterm delivery. Passive smoking, mainly related to the presence of a smoking spouse, increases the risk of low birth weight and preterm birth. Our review confirmed also the benefits of smoking cessation, even in the third trimester, in reducing the risk of small for gestation age or fetal growth restriction and preterm birth. Several studies of tobacco control policies have been shown to be effective in significantly reducing maternal smoking. There is sufficient evidence to infer a causal link between active or passive maternal smoking and low birth weight or preterm delivery. This causal link is compelling and sufficient to justify intensifying efforts to promote rapid progress in tobacco control policies, with the vision of a tobacco-free generation, and smoking cessation with best practices during preconception or pregnancy.

Perinatal mortality in Ireland: inequalities by socio-economic group and country of birth

BACKGROUND

While perinatal mortality rates have decreased in Ireland in recent years, it is not known if this reduction was shared equally among all groups. The aim of this study is to examine inequalities in perinatal mortality by country of birth and socio-economic group in Ireland between 2004 and 2019.

METHODS

Data for the analysis was obtained from the National Perinatal Reporting System dataset, which includes all births (including stillbirths) in Ireland. The rate and risk ratios for perinatal death were calculated for mothers' socio-economic group and country of birth for two time periods (2004-11 and 2012-19). Adjustment was made for mothers' age, marital status, parity and country of birth/socio-economic group. A total of 995 154 births and 5710 perinatal deaths were included in the analysis.

RESULTS

With the exception of African born mothers, the perinatal mortality rate decreased for all groups over time; however, inequalities persisted. Relative to Irish born mothers, the risk for African born mothers increased from 1.63 to 2.00 over time. Adjusting for other variables including socio-economic status reduced but did not eliminate this elevated relative risk. Mothers who were classified as unemployed or engaged in home duties had a higher risk of a perinatal death relative to higher professional mothers, with the relative risk remaining relatively constant over time.

CONCLUSIONS

Reducing inequalities in health is a key objective of the Irish government. Further research is required to identify why perinatal mortality continues to be higher in some groups so that targeted action can be implemented.

Timing of Maternal Smoking Cessation and Newborn Weight, Height, and Head Circumference

OBJECTIVE

To examine the relationship between timing of smoking cessation during pregnancy and anthropometric indices of newborns.

METHODS

Mothers and neonates enrolled in the JECS (Japan Environment and Children's Study), a nationwide birth cohort study, were examined. Patients with full-term neonates were included in the analysis, and 73,025 mother-neonate pairs with complete data were identified. The mothers were classified into six groups according to smoking status during pregnancy (nonsmokers [Q1, n=44,198]; ex-smokers who quit before pregnancy [Q2, n=16,461]; ex-smokers who quit in the first trimester [Q3, n=8,948]; ex-smokers who quit in the second trimester [Q4, n=498]; ex-smokers who quit in the third trimester [Q5, n=651]; and smokers who smoked throughout pregnancy [Q6, n=2,269)]). Data on smoking were based on questionnaires administered in the first, second, or third trimester and 1 month after delivery. The primary outcomes were birth weight, height, and head circumference.

RESULTS

Compared with nonsmokers (Q1), no adverse outcomes were observed for ex-smokers who quit before pregnancy (Q2). The mean adjusted weights of male and female neonates were 135 g and 125 g lower, respectively, in Q6 participants than in Q1 participants. Comparing Q1 and Q6 participants, height was 0.6 cm and 0.7 cm smaller for male and female neonates, respectively. Head circumference in neonates of Q6 participants was 0.3 cm and 0.3 cm smaller for male and female neonates, respectively, than that in Q1 participants. Across all three measures, smoking cessation in the first and second trimester reduced the differential in outcomes between nonsmokers and individuals who smoked throughout pregnancy.

CONCLUSION

Smoking during pregnancy is associated with reduced newborn birth weight, height, and head circumference. Earlier smoking cessation during pregnancy reduces the adverse effects of smoking on fetal growth.

A Qualitative Study to Explore the Determinants of Risky Sexual Behaviors and Pregnancy among Female Adolescents in Sabah, Malaysia

This investigation was performed in Kota Kinabalu, Sabah state, where the highest number of pregnancies is recorded. The purpose of this study was to determine variables associated with hazardous sexual activity and adolescent pregnancy in Sabah, Malaysia. The findings indicate that familial variables, peer interactions, self-esteem, psychiatric concerns, economic considerations, and sex knowledge all play a significant role in hazardous sexual conduct and adolescent pregnancy in Sabah, Malaysia. Information obtained from this study will help the Malaysian government and other officials to design and establish proper interventions that will help alleviate the challenge of high prevalence of teenage pregnancy. It is suggested that sex education be included in the high school curriculum, along with physical and health education in Sabah, Malaysia.

Maternal smoking status during pregnancy and low birth weight in offspring: systematic review and meta-analysis of 55 cohort studies published from 1986 to 2020

BACKGROUND

Maternal smoking during pregnancy may be associated with low birth weight (LBW) in offspring and global risk estimates have not been summarized previously. We aimed to systematically explore evidence regarding maternal smoking and the LBW risk in offspring globally and examine possible causes of heterogeneity across relevant studies.

METHODS

Comprehensive search of PubMed, Ovid Embase, Ovid Medline (R), and Web of science from inception until October 2021 was carried out. A random-effects meta-analysis was used to estimate the pooled odds ratio (OR) and corresponding 95% confidence interval (CI). Restricted cubic spline analysis with three knots was used to further examine the dose-response relationship.

RESULTS

Literature searches yielded 4940 articles, of which 53 met inclusion criteria (comprising 55 independent studies). Maternal smoking during pregnancy was significantly associated with the risk of LBW in offspring (OR = 1.89, 95% CI = 1.80-1.98). Furthermore, an obvious dose-response relationship between the amount of cigarettes daily smoked in pregnancy and the risk of LBW in offspring was observed. The results of subgroup analyses indicated that the risk of maternal smoking on LBW was larger in more recently conducted studies (P = 0.020) and longer period of active smoking during pregnancy (P = 0.002). No evidence of publication bias was found.

CONCLUSIONS

In summary, maternal smoking in pregnancy was significantly associated with a higher risk of LBW in offspring on a global scale. The risk of maternal smoking on infant LBW seems to be increasing over time, and was higher with longer smoking duration throughout pregnancy and more cigarettes smoked daily.

Are infant mortality rates increasing in England? The effect of extreme prematurity and early neonatal deaths

BACKGROUND

Infant mortality has been rising in England since 2014. We examined potential drivers of these trends.

METHODS

We used aggregate data on all live births, stillbirths and linked infant deaths in England in 2006-2016 from the Office for National Statistics. We compared trends in infant mortality rates overall, excluding births at <24 weeks of gestation, by quintile of SES and gestational age.

RESULTS

Infant mortality decreased from 4.78 deaths/1000 live births in 2006 to 3.54/1000 in 2014 (annual decrease of 0.15/1000) and increased to 3.67/1000 in 2016 (annual increase of 0.07/1000). This rise was driven by increases in deaths at 0-6 days of life. After excluding infants born at <24 weeks of gestation, infant mortality continued to decrease after 2014. The risk of infant death was 94% higher in the most versus least deprived SES quintile, which reduced to a 55% higher risk after adjusting for gestational age.

CONCLUSIONS

The observed increase in infant mortality rates since 2014 is wholly explained by an increasing number of deaths at 0-6 days of age among babies born at <24 weeks of gestation. Policies focused on improving maternal health to reduce preterm birth could substantially reduce the socio-economic gap in infant survival.

Behavioral and Enhanced Perinatal Intervention (B-EPIC): A randomized trial targeting tobacco use among opioid dependent pregnant women

BACKGROUND

Opioid use during pregnancy is a significant public health issue. The standard of care for treating opioid use disorder during pregnancy includes medications for opioid disorder (MOUD). However, tobacco use often goes unaddressed among pregnant women on MOUD. In 2018, our team received a National Institute on Drug Abuse (NIDA) funded R34 to conduct a three year-randomized trial to test the feasibility of a novel tobacco intervention for pregnant women receiving MOUD.

AIMS

The aims of this study are: (1) to determine the impact of the B-EPIC intervention on maternal tobacco use and stage of change; (2) to determine the impact of B-EPIC on tobacco-related maternal and infant health outcomes including gestational age at birth, birthweight, NAS diagnosis and severity, and number of ear and respiratory infections during the first six months; (3) to compare healthcare utilization and costs incurred by pregnant patients that receive the B-EPIC intervention versus TAU.

METHODS

We plan to enroll 100 pregnant women on MOUD for this randomized controlled trial (B-EPIC intervention n = 50 and treatment as usual n = 50). A major strength of this study is its wide range of health and economic outcomes assessed on mother, neonate and the infant.

CONCLUSIONS

Despite the very high rates of smoking among pregnant women with OUD, there are few tobacco treatment interventions that have been tailored for this high - risk population. The overall goal of this study is to move towards a tobacco treatment standard for pregnant women receiving treatment for OUD.

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.

The Effects of Different Smoking Patterns in Pregnancy on Perinatal Outcomes in the Southampton Women's Survey

Maternal smoking during pregnancy has established associations with poor perinatal outcomes. Among continuing pregnant smokers, harm-reduction strategies have been suggested, including temporary cessation of smoking during pregnancy, also known as partial quitting. Support for this strategy, however, remains limited. Six hundred and ninety-seven women in the Southampton Women's Survey who smoked at their last menstrual period were categorised into sustained quitters, partial quitters (quit in either the first or third trimester but not both) or sustained smokers (continued to smoke throughout pregnancy). In regression models, compared with infants born to sustained smokers, infants born to sustained quitters and partial quitters were heavier at birth by β = 0.64 standard deviations (SD) (WHO z-score) (95% CI: 0.47-0.80) and 0.48 SD (WHO z-score) (95% CI: 0.24-0.72) respectively, adjusted for confounders, with similar patterns seen for other anthropometric measures (head circumference and crown-heel length). Sustained quitters had longer gestations by β = 3.5 days (95% CI: 1.8-5.2) compared with sustained smokers, but no difference was seen for partial quitters. While sustained quitting remains the most desired outcome for pregnant smokers, partial quitting should be explored as a strategy to reduce some of the harmful effects of smoking on offspring in those who cannot achieve sustained quitting.

Associations between maternal age and socioeconomic status with smoking during the second and third trimesters of pregnancy: a register-based study of 932 671 women in Finland from 2000 to 2015

OBJECTIVES

This study aimed to explore the association between maternal age and smoking during the second and third trimesters of pregnancy across socioeconomic groups and to evaluate the interacting effect of maternal age and socioeconomic status on smoking with a view to informing public health interventions.

DESIGN

This is a register-based study.

SETTINGS

Data from the Finnish Medical Birth Register were cross-linked with background data from Statistics Finland.

PARTICIPANTS

The information of 932 671 pregnant women who gave birth in Finland from 2000 to 2015.

MAIN OUTCOME MEASURES

Maternal smoking during the second and third trimesters of pregnancy by occupation and maternal age.

RESULTS

The proportion of women who smoked during the second and third trimesters of pregnancy was 10.5%. Using women 30-34 years as the reference group, adjusted ORs (aOR) and 95% CIs for smoking were 6.02 (5.81 to 6.24) in women below 20 years and 2.77 (2.71 to 2.84) in women 20 to 24 years. The prevalence of smoking across socioeconomic groups compared with upper-level employees increased, peaking for women in manual occupations (aOR 3.39, 95% CI 3.25 to 3.52) and unemployed women (aOR 4.49, 95% CI 4.30 to 4.68). Significant interactions on the additive scale with the relative excess risk due to interaction >2 were found for unemployed women aged 25-29 years and for teenage mothers and mothers aged 20-24 years across all socioeconomic groups, but not for self-employed women.

CONCLUSIONS

Smoking during the second and third trimesters of pregnancy was most common among teenage mothers across all socioeconomic groups. The association between maternal age and smoking differed by socioeconomic status for young mothers. Interventions should address a wider range of maternal risk factors among young mothers with low socioeconomic status and simultaneously target a broader number of women who smoke during the pregnancy.

Changes in parental smoking during pregnancy and risks of adverse birth outcomes and childhood overweight in Europe and North America: An individual participant data meta-analysis of 229,000 singleton births

BACKGROUND

Fetal smoke exposure is a common and key avoidable risk factor for birth complications and seems to influence later risk of overweight. It is unclear whether this increased risk is also present if mothers smoke during the first trimester only or reduce the number of cigarettes during pregnancy, or when only fathers smoke. We aimed to assess the associations of parental smoking during pregnancy, specifically of quitting or reducing smoking and maternal and paternal smoking combined, with preterm birth, small size for gestational age, and childhood overweight.

METHODS AND FINDINGS

We performed an individual participant data meta-analysis among 229,158 families from 28 pregnancy/birth cohorts from Europe and North America. All 28 cohorts had information on maternal smoking, and 16 also had information on paternal smoking. In total, 22 cohorts were population-based, with birth years ranging from 1991 to 2015. The mothers' median age was 30.0 years, and most mothers were medium or highly educated. We used multilevel binary logistic regression models adjusted for maternal and paternal sociodemographic and lifestyle-related characteristics. Compared with nonsmoking mothers, maternal first trimester smoking only was not associated with adverse birth outcomes but was associated with a higher risk of childhood overweight (odds ratio [OR] 1.17 [95% CI 1.02-1.35], P value = 0.030). Children from mothers who continued smoking during pregnancy had higher risks of preterm birth (OR 1.08 [95% CI 1.02-1.15], P value = 0.012), small size for gestational age (OR 2.15 [95% CI 2.07-2.23], P value < 0.001), and childhood overweight (OR 1.42 [95% CI 1.35-1.48], P value < 0.001). Mothers who reduced the number of cigarettes between the first and third trimester, without quitting, still had a higher risk of small size for gestational age. However, the corresponding risk estimates were smaller than for women who continued the same amount of cigarettes throughout pregnancy (OR 1.89 [95% CI 1.52-2.34] instead of OR 2.20 [95% CI 2.02-2.42] when reducing from 5-9 to ≤4 cigarettes/day; OR 2.79 [95% CI 2.39-3.25] and OR 1.93 [95% CI 1.46-2.57] instead of OR 2.95 [95% CI 2.75-3.15] when reducing from ≥10 to 5-9 and ≤4 cigarettes/day, respectively [P values < 0.001]). Reducing the number of cigarettes during pregnancy did not affect the risks of preterm birth and childhood overweight. Among nonsmoking mothers, paternal smoking was associated with childhood overweight (OR 1.21 [95% CI 1.16-1.27], P value < 0.001) but not with adverse birth outcomes. Limitations of this study include the self-report of parental smoking information and the possibility of residual confounding. As this study only included participants from Europe and North America, results need to be carefully interpreted regarding other populations.

CONCLUSIONS

We observed that as compared to nonsmoking during pregnancy, quitting smoking in the first trimester is associated with the same risk of preterm birth and small size for gestational age, but with a higher risk of childhood overweight. Reducing the number of cigarettes, without quitting, has limited beneficial effects. Paternal smoking seems to be associated, independently of maternal smoking, with the risk of childhood overweight. Population strategies should focus on parental smoking prevention before or at the start, rather than during, pregnancy.

Effects of maternal smoking on body size and proportions at birth: a register-based cohort study of 1.4 million births

OBJECTIVES

The aim of our work was to analyse the effect of maternal smoking on body size and body proportions of newborns when the mother had smoked only during the first trimester, in comparison with continued smoking after the first trimester. Furthermore, we have evaluated how growth restriction associated with maternal smoking contributes to changes in body proportions.

DESIGN

Register-based cohort study SETTING: Maternal Exposure (MATEX) cohort identified from the Finnish Medical Birth Register.

PARTICIPANTS

Singleton births without congenital anomalies and missing data (1.38 million) from 1 January 1991 to 31 December 2016.

METHODS

Logistic regression was used to quantify the effect of maternal smoking, stratified by the maternal smoking status.

OUTCOME MEASURES

Body proportions indicated by low brain-to-body ratio (defined as <10th percentile); high ponderal index and high head-to-length ratio (defined as >90th percentile); small body size for gestational age at birth (defined as weight, length or head circumference <10th percentile) and preterm birth (<37 weeks) and low birth weight (2500 g).

RESULTS

Continued smoking after the first trimester was associated with high ponderal index (OR 1.26, 95% CI 1.23 to 1.28), low brain-to-body ratio (1.11, 1.07-1.15) and high head-to-length ratio (1.22, 1.19-1.26), corresponding with absolute risks of 22%, 10% and 19%, respectively). The effects were slightly lower when smoking had been quit during the first trimester. Similar effects were seen for the body size variables and low birth weight. Preterm birth was not associated with smoking only during first trimester.

CONCLUSIONS

Maternal smoking, independent of smoking duration during pregnancy, was associated with abnormal body proportions resulting from larger reduction of length and head circumference in comparison to weight. The effects of having quit smoking during the first trimester and having continued smoking after the first trimester were similar, suggesting the importance of early pregnancy as a sensitive exposure window.

Chained Risk Assessment for Life-Long Disease Burden of Early Exposures - Demonstration of Concept Using Prenatal Maternal Smoking

Traditional risk factors and environmental exposures only explain less than half of the disease burden. The developmental origin of the health and disease (DOHaD) concept proposes that prenatal and early postnatal exposures increase disease susceptibility throughout life. The aim of this work is to demonstrate the application of the DOHaD concept in a chained risk assessment and to provide an estimate of later in life burden of disease related to maternal smoking. We conducted three systematic literature searches for meta-analysis and reviewed the literature reporting meta-analyses of long-term health outcomes associated with maternal smoking and intermediate risk factors (preterm birth, low birth weight, childhood overweight). In the chained model the three selected risk factors explained an additional 2% (34,000 DALY) of the total non-communicable disease burden (1.4 million DALY) in 2017. Being overweight in childhood was the most important risk factor (28,000 DALY). Maternal smoking was directly associated with 170 DALY and indirectly via the three intermediate risk factors 1000 DALY (1200 DALY in total). The results confirm the potential to explain a previously unattributed part of the non-communicable diseases by the DOHAD concept. It is likely that relevant outcomes are missing, resulting in an underestimation of disease burden.

Origins of disparities in preventable child mortality in England and Sweden: a birth cohort study

OBJECTIVE

To compare mortality in children aged <5 years from two causes amenable to healthcare prevention in England and Sweden: respiratory tract infection (RTI) and sudden unexpected death in infancy (SUDI).

DESIGN

Birth cohort study using linked administrative health databases from England and Sweden.

SETTING AND PARTICIPANTS

Singleton live births between 2003 and 2012 in England and Sweden, followed up from age 31 days until the fifth birthday, death or 31 December 2013.

MAIN OUTCOME MEASURES

The main outcome measures were HR for RTI-related mortality at 31-364 days and at 1-4 years and SUDI mortality at 31-364 days in England versus Sweden estimated using Cox proportional hazards models. We calculated unadjusted HRs and HRs adjusted for birth characteristics (gestational age, birth weight, sex and congenital anomalies) and socioeconomic factors (maternal age and socioeconomic status).

RESULTS

The English cohort comprised 3 928 483 births, 768 RTI-related deaths at 31-364 days, 691 RTI-related deaths at 1-4 years and 1166 SUDIs; the corresponding figures for the Swedish cohort were 1 012 682, 131, 118 and 189. At 31-364 days, unadjusted HR for RTI-related death in England versus Sweden was 1.52 (95% CI 1.26 to 1.82). After adjusting for birth characteristics, the HR reduced to 1.16 (95% CI 0.96 to 1.40) and for socioeconomic factors to 1.11 (95% CI 0.92 to 1.34). At 1-4 years, unadjusted HR was 1.58 (95% CI 1.30 to 1.92) and decreased to 1.32 (95% CI 1.09 to 1.61) after adjusting for birth characteristics and to 1.30 (95% CI 1.07 to 1.59) after further adjustment for socioeconomic factors. For SUDI, the respective HRs were 1.59 (95% CI 1.36 to 1.85) in the unadjusted model, and 1.40 (95% CI 1.20 to 1.63) after accounting for birth characteristics and 1.19 (95% CI 1.02 to 1.39) in the fully adjusted model.

CONCLUSION

Interventions that improve maternal health before and during pregnancy to reduce the prevalence of adverse birth characteristics and address poverty could reduce child mortality due to RTIs and SUDIs in England.

Risk factors for reduced fetal movements in pregnancy: A systematic review and meta-analysis

Maternal perception of reduced fetal movements (RFM) is an important clinical marker to identify women at higher risk of adverse perinatal outcomes. Preventing and reducing stillbirths can only be achieved through better detection and management of women with RFM, however the characteristics of women who present with RFM in pregnancy vary. A systematic review was conducted to explore the risk factors associated with reduced fetal movements (RFM) in pregnancy. PubMed, EMBASE, CINAHL, Maternity and Infant Care, PsycINFO and Science Citation Index were searched, from their inception date, for studies published up to 16^th May 2019. Non-randomised observational studies reporting risk factors in pregnant women presenting with a primary complaint of RFM during pregnancy were included. The quality of the included studies was assessed with the Quality in Prognosis Studies (QUIPS) tool. Meta-analyses were performed using RevMan 5.3 software for each identified risk factor where two or more studies reported on the same risk factor. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were followed. Twenty-seven studies reporting on risk factors for RFM during pregnancy were included. Women presenting with RFM during pregnancy are more likely to be Caucasian, smokers, and have an anterior placenta, oligohydramnios and polyhydramnios. No difference was found in parity or the mean age of women presenting with RFM and women who did not present with RFM. Previous caesarean section, postdates >42 weeks', and other medical conditions, including diabetes and hypertensive disorders were not predictive for RFM during pregnancy. Modifiable and non-modifiable risk factors associated with RFM in pregnancy were identified. These results can be used to raise awareness of factors associated with RFM, and prompt women to attend their maternity care provider should concerns arise.

Smoking cessation during pregnancy: a population-based study

OBJECTIVE

To measure the prevalence of smoking cessation during pregnancy and to identify factors associated with its occurrence.

METHODS

The present survey included all puerperal women living in the municipality of Rio Grande, RS, whose birth occurred between January 1 and December 31, 2013. A single standardized questionnaire was applied, in the hospital, within 48 hours of delivery. Multivariate analysis was performed using Poisson regression with robust variance.

RESULTS

The prevalence of smoking cessation among the 598 parturients studied was 24.9% (95%CI 21.5-28.6). After adjusting for confounding factors, mothers aged 13 to 19 years (PR = 1.76; 95%CI 1.13-2.74), who had higher family income (PR = 1.83; 95%CI, 1.23-2.72), higher educational level (PR = 2.79; 95%CI 1.27-6.15), higher number of prenatal appointments (PR = 1.84; 95%CI 1.11-3.05), and who did not smoke in the previous pregnancy (PR = 2.93; 95% CI, 1.95-4.41) presented a higher prevalence ratio of smoking cessation.

CONCLUSIONS

Although pregnancy is a window of opportunity for smoking cessation, the rate of cessation was low. The prevalence of cessation was higher among mothers with lower risk of complications, suggesting the need for interventions prioritizing pregnant women of lower socioeconomic levels.

A pilot study of the Tobacco Treatment Guidelines for High-Risk Groups (TOB-G) for pregnant and postpartum women

INTRODUCTION

Maternal smoking constitutes a significant risk to the fetus and is associated with multiple adverse pregnancy outcomes. Despite this, an estimated 6-19% of women in Europe smoke during pregnancy. We conducted a pilot study to examine the feasibility and effectiveness of the clinical practice recommendations of the 2017 Tobacco Cessation Guidelines for High-Risk Groups (TOB-G) for pregnant and postpartum women in an outpatient obstetrics setting.

METHODS

The guideline recommendations were tested on a sample of 67 pregnant women recruited from obstetrics outpatient visits. Pregnant women who smoked received three behavioural counselling sessions through a combination of face-toface and telephone consultations by a midwife trained in the TOBG tobacco treatment recommendations. Smoking status was assessed at 1 month and at 6 months follow-up via self-report.

RESULTS

Seventy-one per cent of pregnant smokers screened agreed to participate in the counselling intervention. Pregnant women participants (mean age, M=31.73 years, SD±6.09) smoked for an average of 12.2 (SD±6.55) years. Women reported smoking an average of 4.82 (SD±4.14) cigarettes per day with 51% reporting smoking within 30 minutes of waking, an indicator of higher levels of nicotine addiction. Rates of smoking abstinence among pregnant women undergoing the counselling intervention were 43.9% and 45.6% at the 1 month and at 6 months follow-up, respectively. Replacing those participants with missing data as smokers, the quit rates were 26.9% and 38.8% at the 1 month and 6 months follow-up, respectively.

CONCLUSIONS

The counselling intervention delivered to pregnant women who smoke was feasible to implement in a manner that was consistent with the TOB-G guideline recommendations in an outpatient obstetrics setting. Future work should focus on increasing uptake of evidence-based tobacco treatment recommendations in outpatient obstetrics settings.

Educational disparities in perinatal health in Denmark in the first decade of the 21st century: a register-based cohort study

OBJECTIVE

To investigate socioeconomic differences in six perinatal health outcomes in Denmark in the first decade of the 21st century.

DESIGN

A population-based cohort study.

SETTING

Danish national registries.

PARTICIPANTS

A total of 646 829 live born children and 3076 stillborn children (≥22+0 weeks of gestation) born in Denmark from 2000 to 2009. We excluded children with implausible relations between birth weight and gestational age (n=644), children without information on maternal country of origin (n=138) and implausible values of maternal year of birth (n=36).

MAIN OUTCOME MEASURES

We investigated the following perinatal health outcomes: stillbirth, neonatal and postneonatal mortality, small-for-gestational age, preterm birth grated into moderate preterm, very preterm and extremely preterm, and congenital anomalies registered in the first year of life.

RESULTS

Maternal educational level was inversely associated with all adverse perinatal outcomes. For all examined outcomes, the risk association displayed a clear gradient across the educational levels. The associations remained after adjustment for maternal age, maternal country of origin and maternal year of birth. Compared with mothers with vocational education, mothers with more than 15 years of education had an adjusted risk ratio for stillbirth of 0.64(95% CI 0.56 to 0.72). The corresponding adjusted risk ratios for neonatal mortality, postneonatal mortality, congenital anomalies, moderate preterm birth and small-for-gestational age were, respectively, 0.79(95% CI 0.67 to 0.93), 0.57(95% CI 0.42 to 0.78), 0.87(95% CI 0.83 to 0.91), 0.80(95% CI 0.77 to 0.83) and 0.83(95% CI 0.81 to 0.85).

CONCLUSION

Substantial educational inequalities in perinatal health were still present in Denmark in the first decade of the 21st century.

Joint Effect of Maternal Tobacco Smoking and Pregestational Diabetes on Preterm Births and Congenital Anomalies: A Population-Based Study in Northern Italy

Smoking and pregestational diabetes (PGD) are recognized risk factors for adverse pregnancy outcomes, but to date, no population-based study has investigated their joint effects. Using hospital discharges, we identified all women with PGD delivering in Emilia-Romagna region during 2007-2010 matched 1 : 5 with parturients without diabetes. Our study endpoints were preterm births and congenital anomalies. We measured interaction between PGD and maternal smoking, by calculating excess prevalence and prevalence ratio due to interaction, relative excess risk due to interaction (RERI), attributable proportion (AP), and the synergy index (S). Analyses were performed in the overall study population and in the subgroup whose PGD was validated through diabetes registers. The study included 992 women with PGD (10.5% smokers) and 4788 comparison women (11.9% smokers). The effects of PGD and maternal tobacco smoking were greater than additive for both preterm birth (excess prevalence due to interaction = 11.7%, excess ratio due to interaction = 1.5, RERI = 2.39, AP = 0.51, S = 2.82) and congenital anomalies (excess prevalence due to interaction = 2.2%, excess ratio due to interaction = 1.3, RERI = 1.33, AP = 0.49, S = 5.03). Joint effect on both endpoints was confirmed in the subgroup whose PGD status was validated. In conclusion, we found that maternal tobacco smoking and PGD intensify each other's effect on preterm birth and congenital anomalies.

Prophylaxis and treatment of foetal growth restriction

Foetal growth restriction (FGR) and associated placental pathologies such as pre-eclampsia and stillbirth arise in early pregnancy when inadequate remodelling of maternal spiral arteries leads to persistent high-resistance low-flow uteroplacental circulation. Current interventions concentrate on targeting the placental ischaemia-reperfusion injury and oxidative stress associated with an imbalance in angiogenic/anti-angiogenic factors. Recent meta-analyses confirm that aspirin modestly reduces the risk for small-for-gestational-age pregnancy in high-risk women. A dose of ≥100 mg starting by 16 weeks of gestation is recommended. In vitro and in vivo studies suggest that low-molecular-weight heparin may prevent FGR; further research is needed to confirm efficacy. Once FGR is diagnosed, no treatment will improve foetal growth. Potential FGR therapies such as phosphodiesterase type-5 inhibitors or maternal VEGF gene therapy aim to improve poor placentation and/or uterine blood flow. Melatonin, creatine and N-acetyl cysteine have potential as novel neuroprotective and cardioprotective agents in FGR.

The MATEX cohort - a Finnish population register birth cohort to study health effects of prenatal exposures

Background

The prevalence of chronic diseases, such as immune, neurobehavioral, and metabolic disorders has increased in recent decades. According to the concept of Developmental Origin of Health and Disease (DOHaD), developmental factors associated with environmental exposures and maternal lifestyle choices may partly explain the observed increase. Register-based epidemiology is a prime tool to investigate the effects of prenatal exposures over the whole life course.

Our aim is to establish a Finnish register-based birth cohort, which can be used to investigate various (prenatal) exposures and their effects during the whole life course with first analyses focusing on maternal smoking and air pollution. In this paper we (i) review previous studies to identify knowledge gaps and overlaps available for cross-validation, (ii) lay out the MATEX study plan for register linkages, and (iii) analyse the study power of the baseline MATEX cohort for selected endpoints identified from the international literature.

Methods/design

The MATEX cohort is a fully register-based cohort identified from the Finnish Medical Birth Register (MBR) (1987–2015). Information from the MBR will be linked with other Finnish health registers and the population register to link the cohort with air quality data. Epidemiological analyses will be conducted for maternal smoking and air pollution and a range of health endpoints.

Discussion

The MATEX cohort consists of 1.75 million mother-child pairs with a maximum follow up time of 29 years. This makes the cohort big enough to reach sufficient statistical power to investigate rare outcomes, such as birth anomalies, childhood cancers, and sudden infant death syndrome (SIDS). The linkage between different registers allows for an extension of the scope of the cohort and a follow up from the prenatal period to decades later in life.

Electronic supplementary material

The online version of this article (10.1186/s12889-017-4881-8) contains supplementary material, which is available to authorized users.

Financial Incentives Alone Versus Incentivized Partner Support for Promoting Smoking Cessation During Pregnancy and Postpartum: Protocol for a Non-Randomized Single-Blinded Study

Background

Smoking tobacco remains the most significant modifiable cause of adverse pregnancy outcomes and contributor to ongoing maternal and infant ill-health. Pregnancy for many is a time of heightened health focus, with the primary motivation being the well-being of the unborn child. Yet, many women continue to smoke throughout their pregnancy. Despite this heightened motivation and known health risks, interventions to date have not effectively curbed the rate of smoking during pregnancy and they remain as high as rates among the general population. One promising strategy has been to incentivize these women to quit. However, incentives-based studies have not shown or reported long-term efficacy. Here, we present the protocol of a trial exploring the effect of incentivized partner support on pre- and postpartum smoking cessation.

Objective

The aim of this study is to determine whether providing incentives to both the expectant mother and her support person in promoting short- and long-term smoking cessation during pregnancy is more effective than incentives to the expectant mother alone.

Methods

This protocol is designed as a non-randomized, single-blinded trial to determine the efficacy of incentivized partner support, compared to participant incentive only, in promoting smoking cessation during pregnancy and postpartum. All eligible pregnant women receiving antenatal care via the Tasmanian Health Service (Australia) will be invited to participate. Participants will be eligible for monthly quit-contingent shopping vouchers if they verify, via carbon monoxide breath sample, as being abstinent from smoking. Participating women will be eligible for vouchers until 6-months postpartum and will be followed up at 12-months postpartum.

Results

The recruitment phase of this study has concluded. Results are expected to be published by the end of 2018.

Conclusions

This study protocol extends the current literature on incentivized smoking cessation interventions for pregnant women by assessing the influence of incentivizing a support partner on short- and long-term abstinence. Key ethical considerations are discussed including potential for receipt (or not) of quit-contingent vouchers impacting negatively on the participant’s relationship with their partner. The findings of the study may have important implications for the role support partners are assigned in smoking cessation programs targeting pregnant women.

Trial Registration

Australian New Zealand Clinical Trials Registry (ACTRN): 12615001158550; https://www.anzctr.org.au/ Trial/Registration/TrialReview.aspx?id=367981 (Archived by WebCite at http://www.webcitation.org/6tGKO28uh)

Profile of Maternal Smokers Who Quit During Pregnancy: A Population-Based Cohort Study of Tasmanian Women, 2011-2013

Introduction

Smoking remains the single-most significant preventable cause of poor pregnancy outcomes, yet around 12% of Australian women smoke during pregnancy. Many women are motivated to quit when they find out they are pregnant, yet few are successful. While previous studies have examined the profile of the maternal smoker compared to her nonsmoking counterpart (Aim 1), little is known about what differentiates women who quit during pregnancy to those who do not (Aim 2). Here, we present results from a study investigating the characteristics of women who were able to quit during pregnancy.

Methods

Data were drawn from the Tasmanian Population Health database of women who had received antenatal care between 2011 and 2013 (n = 14300). Data collected included age, relationship status and ethnicity of expectant mothers, antenatal details, mental health conditions, and drug use. Independent samples t tests were used to compare differences between women who had, and those who had not, quit during pregnancy. The 19.4% of women who self-reported as smoking in the first half (first 20 weeks) of their pregnancy were further grouped and analyzed comparing those who reported still smoking in the second half of their pregnancy (smokers: n = 2570, 92.4%) to those who quit (quitters: n = 211, 7.6%).

Results

Quitters (57.8%) were more likely to be in a relationship than their non-quitting counterparts (49.6%, p = .022) and were less likely to suffer from postnatal depression (2.4% vs. 6.0%, p = .029). No other differences between quitters and smokers were observed.

Conclusions

Determining the profile of women who are able to quit during pregnancy may be important to improve the relatively poor cessation rates among maternal smokers and may assist in more effectively targeting at-risk women.

Implications

Smoking cessation interventions have traditionally targeted socially disadvantaged women, for good reason: the majority of smoking pregnant women fall into this category. However, despite the significant attention and resources dedicated to antenatal smoking cessation interventions, most are ineffective with only 7.6% of the present sample quitting smoking during pregnancy. This paper may assist in developing more effective antenatal smoking cessation interventions by more clearly describing the profile of maternal smokers who successfully quit during pregnancy. Specifically, this paper highlights the need to acknowledge and address women's relationship status and mental health in order to promote smoking cessation in pregnancy.

Tailoring a NICU-Based Tobacco Treatment Program for Mothers Who Are Dependent on Opioids

OBJECTIVE

To collect formative information to design a tailored tobacco treatment intervention for women with newborns treated or evaluated for neonatal abstinence syndrome and to explore current tobacco use behaviors and facilitators and barriers to smoking cessation.

DESIGN

Qualitative descriptive study.

SETTING

An academic medical center in the southern United States.

PARTICIPANTS

Mothers (N = 11) of newborns who were treated or evaluated for neonatal abstinence syndrome at birth within the preceding 3 months. Women recruited were older than 18 years and reported opioid dependence and smoking during pregnancy.

METHODS

Participants took part in semistructured individual interviews that lasted approximately 1 hour. Interviews were professionally transcribed and analyzed in MAXQDA using content analysis.

RESULTS

Five themes emerged from the data: Strategizing to Reduce Risk, Desire to Quit Smoking in the Future, Holding on to Smoking While Working Through Recovery, Feeling Judged by Nurses, and Feeling Supported and Empowered by Nurses. Participants reported that they to reduce risk to their newborns by avoiding second- and thirdhand smoke exposure. Participants wanted to stop smoking but reported many barriers, including multiple life stressors compounded by their newborns' extended stays in the hospital. However, most participants described overall positive experiences and the support of health care providers.

CONCLUSION

Holistic tobacco treatment programs that incorporate stress relief and social support and are led by trusted health care providers have the potential to be effective to reduce smoking in new mothers with histories of opioid dependence disorders and smoking and whose newborns are in the NICU.

Cigarette Smoking During Pregnancy: Do Complete Abstinence and Low Level Cigarette Smoking Have Similar Impact on Birth Weight?

OBJECTIVES

Despite awareness of negative health outcomes associated with smoking, pregnant smokers might reduce their tobacco consumption thinking that a low smoking rate reduces smoking-related negative birth outcomes. We aimed to assess in a clinical sample whether there is a smoking rate that would not impact on birth weight (BW).

METHODS

Pregnant smokers ≥18 years, gestational age of 9-20 weeks of amenorrhea, motivated to quit smoking, smoking ≥5 cigarettes/day (cpd) and their newborns (381 singleton, live births) were included in this secondary analysis of a French smoking cessation trial.

RESULTS

The mean BW when the mother quit smoking was 3417 g (95 % CI: 3098-3738 g); when smoking >0<5 cpd, 3081g (3003-3159 g); when smoking 5-9 cpd, 3043 g (2930-3157 g); and when smoking ≥10 cpd, 2831 g (2596-3157 g) (p = .006). The corresponding effect sizes ranged from medium to large (Cohen's d for BW: 0.54, 0.57 and 0.85) compared to BW when the mother quit. In the multivariable analysis, adjusted for all significant confounders, when the mother smoked on average >0<5 cpd, the loss in BW was 228 g; when smoking 5-9 cpd, 251 g; and when smoking ≥10 cpd, 262 g (all p ≤ .02) compared to newborns' BW of mothers who stopped smoking since quit date.

CONCLUSIONS

Even low cigarette consumption during pregnancy is associated with BW loss. All efforts should be made to help pregnant smokers quit completely during their pregnancy.

IMPLICATIONS

As an alternative to quitting smoking, pregnant smokers reduce their smoking rate thinking that this diminishes smoking-related negative health outcomes. No study has established whether low smoking rate (more than 0 but less than 5 cpd) during pregnancy impacts BW compared to abstinence from smoking. Among treatment-seeking pregnant smokers BW of newborns of mothers who smoked even less than 5 cpd was significantly lower than of those whose mothers quit; effect sizes of different consumption levels on BW ranged from moderate (>0<5 cpd) to large (≥10 cpd). Even low smoking rate is associated with reduced BW compared to complete maternal smoking abstinence.

Reducing tobacco smoking and smoke exposure to prevent preterm birth and its complications

Tobacco smoking and smoke exposure during pregnancy are associated with a range of adverse health outcomes, including preterm birth. Also, children born preterm have a higher risk of complications including bronchopulmonary dysplasia and asthma when their mothers smoked during pregnancy. Smoking cessation in early pregnancy can help reduce the adverse impact on offspring health. Counselling interventions are effective in promoting smoking cessation and reducing the incidence of preterm birth. Peer support and incentive-based approaches are likely to be of additional benefit, whereas the effectiveness of pharmacological interventions, including nicotine replacement therapy, has not definitely been established. Smoke-free legislation can help reduce smoke exposure as well as maternal smoking rates at a population level, and is associated with a reduction in preterm birth. Helping future mothers to stop smoking and protect their children from second hand smoke exposure must be a key priority for health care workers and policy makers alike.

Maternal smoking during pregnancy and risk of stillbirth: results from a nationwide Danish register-based cohort study

INTRODUCTION

Maternal smoking during pregnancy has been associated with an increased risk of stillbirth. Only a few studies have been conducted to determine whether smoking affects the risk of antepartum and intrapartum stillbirth differently or whether smoking cessation in early pregnancy reduces the risk. Previous results are inconclusive. We addressed these questions in a large Danish population-based cohort study.

MATERIAL AND METHODS

From the Danish Medical Birth Register, we identified 841 228 singleton births in Denmark between 1997 and 2010 and gathered detailed information on maternal smoking during pregnancy and the vital status of the infant. Associations (odds ratios with 95% confidence intervals) between maternal smoking and risk of stillbirth overall and separately for antepartum and intrapartum stillbirth were analyzed using logistic regression models (generalized estimating equations), adjusting for potential confounders.

RESULTS

Any smoking during pregnancy increased the risk of stillbirth, both overall (odds ratio 1.42, 95% confidence interval 1.30-1.55) and for antepartum (odds ratio 1.38, 95% confidence interval 1.25-1.53) and intrapartum (odds ratio 1.52, 95% confidence interval 1.18-1.96) stillbirths. Women who quit smoking at the beginning of the second trimester at the latest had no increased risk of stillbirth overall (odds ratio 1.03, 95% confidence interval 0.80-1.32).

CONCLUSIONS

Maternal smoking during pregnancy increases the risk of stillbirth, both overall and for antepartum and intrapartum stillbirth separately. Women who quit smoking in the beginning of their pregnancy reduce their risk compared with that of non-smokers.

Recruiting Pregnant Indigenous Women Who Smoke into a High Contact Incentivized Cessation Trial: A Feasibility Study

INTRODUCTION

Smoking prevalence among pregnant indigenous women is disproportionately higher than for nonindigenous pregnant women. Incentives have been shown to increase retention in and the effectiveness of smoking cessation programs. To trial if this could work for indigenous women, we aimed to recruit and observe retention of Māori (New Zealand indigenous people) pregnant women that smoke into a cessation program using incentives.

METHODS

A parallel group, randomized controlled feasibility trial was undertaken in New Zealand. Pregnant Māori women who smoked were recruited through health practitioners, social media, and general media advertising. Outcomes included ease of recruitment, enrollment rate, retention, cost, and time and distance traveled to visit participants.

RESULTS

Seventy-four women were referred for the trial over 7 months. The highest enrollment rate was among self-referrals from media (6 of 10), then women referred from cessation providers (47%, 8 of 17). About three-quarters of women referred from health professionals did not enroll. Only 32% (24) were randomized. Nine women completed the intervention, three withdrew, and 12 were lost to follow-up. On average, it took less time to contact abstinent participants (29 vs. 43 minutes for nonabstinent women). No deception was noted.

CONCLUSIONS

Recruitment was difficult and varied by source of first contact. Once enrolled, it was feasible to maintain intensive contact with participants who stayed engaged. The number lost to follow-up was high. We concluded that the tenor of trial promotion could have influenced recruitment and retention rates. Further research with indigenous women is needed to identify better recruitment and retention methods.

IMPLICATION

With the rising cost of research and the increased competition for funds, it is important to have evidence that intervention studies with minority group pregnant women who smoke are feasible. Maintaining contact with participants seemed feasible, but the tenor of trial promotion and type of recruitment strategy could influence enrollment and retention of sufficient numbers of participants. Nonjudgmental supportive advertising and invitations direct to women may work better than relying on health professionals as recruiters.

Thin mother, obese child? A review of early risk factors for obesity in offspring

PURPOSE OF REVIEW

The huge percentages of persons with obesity in many countries constitute a public health crisis. The severe consequences of obesity for physical health and emotional wellbeing already emerge in childhood. Therefore, the acknowledgment of early risk factors is essential to provide recommendations for prevention strategies. This review outlines the current state of research concerning early risk factors for obesity, that is, factors that even contribute to later obesity of the offspring during gestation. In this regard, this review specifically addresses the link between restricted eating behavior of the mother and obesity in her offspring. We systematically searched for articles in PsychINFO, PsychINDEX, MEDLINE, PubMed, MEDPILOT, and Web of Science, and we identified additional studies in bibliographies.

RECENT FINDINGS

Although some risk factors (e.g., short period of breastfeeding, gestational diabetes, and high maternal BMI) have a vast evidence base, others (e.g., restricted eating behavior and second-hand smoking) are insufficiently studied.

SUMMARY

Physical activity and diet programs in pregnancy can reduce not only the occurrence of gestational diabetes, but also the risk of inappropriate weight gain. As smoking during pregnancy and inappropriate eating behavior are associated with lower education, psychoeducation, for instance in sex education classes, could be easily conceivable.

Relationship of trimester-specific smoking patterns and risk of preterm birth

BACKGROUND

In 2011, the US national rate of smoking early in pregnancy was 11.5%. Unfortunately, our home state of Ohio had a rate twice as high at 23%. Smoking in pregnancy remains one of the most important modifiable risk factors for pregnancy complications, specifically preterm birth.

OBJECTIVE

The objective of the study was to quantify the preterm birth risk to various trimester-specific smoking behaviors.

STUDY DESIGN

The study was a population-based, retrospective cohort study of singleton non-anomalous live births, using Ohio birth records 2006 to 2012. Preterm birth rates were compared between non-smokers and women who smoked in the preconception period only, those who quit smoking after the 1st and 2nd trimesters, and those who smoked throughout pregnancy. Multivariate logistic regression quantified the risk of smoking with cessation at various times in pregnancy and preterm birth risk, adjusted for maternal race, education, age, Medicaid use, marital status, and parity. A stratified analysis was performed on the basis of preterm birth subtype: spontaneous preterm birth versus indicated preterm birth. We also performed an additional analysis stratifying for maternal race using the 2 largest categories of race (non-Hispanic white and non-Hispanic black).

RESULTS

Of the 913,757 birth records analyzed, nearly 25% of the women reported some smoking behavior on the birth certificate data. Of smokers, less than half quit during pregnancy (38.8% vs 61.2% smoked throughout pregnancy). Early quitters had a similar preterm birth rate compared with non-smokers. Women who smoked through the 1st trimester only did not have a significant increase in their overall preterm birth odds ratio <37 weeks; however, it did increase the odds of extreme preterm birth <28 weeks by 20% (adjusted odds ratio, 1.20; 95% confidence interval [CI], 1.02, 1.40). Quitting late in pregnancy resulted in the highest odds ratio increase: 70% for preterm birth <37 weeks (adjusted odds ratio 1.70; CI, 1.60, 1.80), even after adjustment for the confounding influences. Quitting smoking early in pregnancy after the 1st trimester did not increase the overall risk of spontaneous or indicated preterm birth <37 weeks significantly. However, quitting after the 1st trimester was associated with a significant increase in risk of extreme spontaneous preterm birth <28 weeks, an effect not seen with indicated preterm birth <28 weeks. Delaying cessation until late in pregnancy-after the 2nd trimester-was associated with the highest risk increases, 65% increased odds of spontaneous and 78% increase in odds of indicated preterm births. The rate of preterm births to non-Hispanic black mothers was increased in all categories over those of non-Hispanic white mothers. The relative influence of smoking cessation in pregnancy was similar in black compared with white mothers. The effect modification in the regression model was analyzed and revealed no significant interaction between race and smoking patterns on preterm birth risk.

CONCLUSION

Smoking throughout pregnancy is associated with an increased risk of preterm birth. However, quitting early in pregnancy negates this risk. Widespread programs aimed at smoking cessation early in pregnancy could have a significant impact on reducing the rate of preterm birth nationally.

Women's Longitudinal Patterns of Smoking during the Pre-Conception, Pregnancy and Postnatal Period: Evidence from the UK Infant Feeding Survey

BACKGROUND

An understanding of women's longitudinal patterns of smoking during the pre-conception, pregnancy and postnatal period and the factors associated with these patterns could help better inform smoking cessation services and interventions.

METHODS

Latent class analysis (LCA) was used to empirically identify women's smoking patterns in a sample of 10,768 mothers from the 2010 UK Infant Feeding Survey. Multinomial logistic regression was used to identify characteristics associated with these patterns.

RESULTS

LCA identified five distinct smoking patterns during the pre-conception, pregnancy and postnatal period: "non-smokers" (74.1% of women); "pregnancy-inspired quitters" (10.2%); "persistent smokers" (10.1%); "temporary quitters" (4.4%); and postnatal quitters (1.1%). Smoking patterns varied markedly according to socio-demographic variables and parity. After adjusting for these variables, mothers who lived during pregnancy with a partner who smoked were more likely to be temporary quitters (aOR 2.64, 95% CI 1.74-3.99) or persistent smokers (aOR 3.32, 95% CI 2.34-4.72) than pregnancy-inspired quitters. Mothers who lived during pregnancy with someone else other than a partner who smoked were more likely to be persistent smokers (aOR 2.34, 95% CI 1.38-3.97) or postnatal quitters (aOR 2.97, 95% CI 1.07-8.24) than pregnancy-inspired quitters. Mothers given information on how their partner could stop smoking if they lived during pregnancy with a smoking partner were less likely to be persistent smokers (aOR 0.42, 95% CI 0.27-0.65) than pregnancy-inspired quitters.

CONCLUSION

Health professionals should ask about smoking at every opportunity, and refer women who self-report as current smokers to an evidence based smoking cessation service.

Investigating the link between smoke-free legislation and stillbirths

Despite considerable recent progress in tobacco control, smoking and second-hand smoke exposure continue to pose a major health threat to adults, children, and (unborn) babies. There is increasing evidence that implementation of smoke-free legislation, through reducing smoking and smoke exposure, has the potential to improve population health. In this editorial we focus on the research on smoke-free legislation in relation to stillbirths, summarizing the findings to-date, reflecting on methodological issues that need to be considered when interpreting this evidence base, and highlighting some key next steps to further strengthen the evidence in order to inform evidence-based policy making.

Characteristics associated with breastfeeding behaviors among urban versus rural women enrolled in the Kansas WIC program

The Special Supplemental Nutrition Program for Women, Infants and Children (WIC) is a public nutritional assistance program for low-income women and their children up to age five. This study provides insight into maternal characteristics associated with breastfeeding among urban versus rural women. A secondary analysis was conducted using the Pregnancy Nutrition Surveillance System dataset of women enrolled in the Kansas WIC program in 2011. Geographic residency status was obtained through application of the Census tract-based rural-urban commuting area codes. Descriptive variables included maternal demographics, health, and lifestyle behaviors. A multivariable binary logistic regression was used to obtain adjusted odds ratios with 95 % confidence intervals. The outcome variable was initiation of breastfeeding. A P value of ≤0.05 was considered statistically significant. The total sample size was 17,067 women. Statistically significant differences regarding socio-demographics, program participation, and health behaviors for urban and rural WIC participants were observed. About 74 % of all WIC mothers initiated breastfeeding. Urban women who were Hispanic, aged 18-19, high school graduates, household income >$10,000/year, and started early prenatal care were more likely to breastfeed. Urban and rural women who were non-Hispanic black with some high school education were less likely to breastfeed. Increased breastfeeding initiation rates are the result of a collaborative effort between WIC and community organizations. Availability of prenatal services to rural women is critical in the success of breastfeeding promotion. Findings help inform WIC program administrators and assist in enhancing breastfeeding services to the Kansas WIC population.

Interpregnancy interval and birth defects

BACKGROUND

Interpregnancy interval is a risk factor for various adverse birth outcomes including birth defects. We investigated the relationship between interpregnancy interval and birth defects.

METHODS

We conducted a retrospective cohort study using linked data from Nevada Birth Outcomes Monitoring System and birth certificate data for 124,341 singleton live births, of which 4641 infants had 7192 birth defects, among Nevada resident women between 2006 and 2011. We used logistic regression to assess factors independently associated with birth defects.

RESULTS

Women who had an interpregnancy interval of 36 months or more, adjusted odds ratio (AOR) = 1.16, 95% confidence interval [CI], 1.01-1.33, were more likely to have an infant with a birth defect compared with women with an interpregnancy interval of 18 to 23 months. Other independent risk factors for birth defects included male infants, AOR = 1.34, 95% CI, 1.26-1.42; maternal age (30-34 years) and advanced maternal age (35 years and older), AOR = 1.10, 95% CI, 1.01-1.19 and AOR = 1.29, 95% CI, 1.18-1.42, respectively; being a Black woman, AOR = 1.46, 95% CI, 1.32-1.61; three and four or more previous births, AOR = 1.12, 95% CI, 1.02-1.23 and AOR = 1.24, 95% CI, 1.11-1.38, respectively; smoking, AOR = 1.23, 95% CI, 1.10-1.38; and prescription drug use, AOR = 1.14, 95% CI, 1.07-1.21.

CONCLUSION

A long interpregnancy interval is an independent risk factor for birth defects. It may be helpful for maternal and child health programs and health care providers to highlight the deleterious effects of a long interpregnancy interval.

Association of reported trimester-specific smoking cessation with fetal growth restriction

OBJECTIVE

To assess the association of reported smoking cessation at various time points during pregnancy with fetal growth restriction.

METHODS

This was a population-based retrospective cohort study of singleton nonanomalous live births using Ohio birth certificates, 2006-2012. Outcomes of women who reported smoking only in the 3 months before conception and women who reported smoking through the first, second, or third trimester were compared with a referent group of nonsmokers. Multivariate logistic regression assessed the association between smoking cessation at various times in pregnancy and fetal growth restriction less than the 10th and 5th percentiles.

RESULTS

Of 927,424 births analyzed, 75% of mothers did not smoke. Of smokers, 24% smoked preconception only, 10% quit after the first trimester, 4% quit after the second trimester, and 59% smoked throughout pregnancy. The rate of fetal growth restriction less than the 10th and 5th percentiles among nonsmokers was 8.1% and 3.6%, respectively. Although smoking only in the preconception period did not significantly increase fetal growth restriction risk, smoking in any trimester did. The adjusted odds ratio (95% confidence interval) for fetal growth restriction less than the 10th and 5th percentiles, respectively, of cessation after the first trimester was 1.19 (1.13-1.24) and 1.25 (1.17-1.33) and 1.67 (1.57-1.78) and 1.83 (1.68, 1.99) for cessation after the second trimester. Women who reported smoking throughout pregnancy had the highest risks of fetal growth restriction, 2.26 (2.22-2.31) and 2.44 (2.37-2.51), after accounting for the influence of race, low socioeconomic status, and medical comorbidities.

CONCLUSION

Smoking of any duration during pregnancy is associated with an increased risk of fetal growth restriction with decreasing risk the earlier that cessation occurs. Smoking cessation programs should focus on the benefit of quitting as early in pregnancy as possible.

LEVEL OF EVIDENCE

II.

Are Meteorological Conditions within the First Trimester of Pregnancy Associated with the Risk of Severe Pre-Eclampsia?

BACKGROUND

Severe pre-eclampsia (SPE) is the second cause of maternal death in developed countries. The literature suggests different risk factors for early- and late-onset pre-eclampsia. SPE is usually related to the early-onset type. Pre-eclampsia rate exhibits seasonal variation. However, the weather-SPE association is still unknown. We examined the associations between maternal exposure to meteorological parameters after conception and SPE.

METHODS

From 2008 to 2011, all deliveries of women living in the Yvelines area, France, have been prospectively registered. Meteorological measurements from weather stations scattered inside Yvelines were averaged on two exposure windows: early-pregnancy (30 days after conception) and first-trimester (90 days after conception). The relationship between SPE and season of conception was also examined. Hierarchical complementary log-log regression models were used to estimate the weather-SPE association.

RESULTS

SPE was diagnosed in 526 (0.8%) out of 63,633 singleton pregnancies. Increasing temperature or sunshine across both windows was associated with increased SPE risk. Early-pregnancy minimum temperature showed the strongest effect with adjusted odds ratio (OR) per 1 degree Celsius: 1.03 [95% confidence interval (CI) 1.01, 1.04]. The risk of SPE was higher when conception was in summer as compared to winter (OR 1.53, 95% CI 1.27, 1.85). Effect estimates showed only small variations in sensitivity analyses.

CONCLUSIONS

Our findings of a weather impact during early pregnancy on SPE may provide a new clue for understanding the causes of pre-eclampsia. Further investigation into the biologic mechanisms for this finding is required.

Intrapartum corticosteroid use significantly increases the risk of gestational diabetes in women with inflammatory bowel disease

BACKGROUND AND AIMS

Women with inflammatory bowel disease (IBD) may be at higher risk of adverse pregnancy outcomes. This study compared perinatal outcomes in women with and without IBD.

METHODS

The population-based Data Integration, Measurement, and Reporting (DIMR) administrative discharge database was used to identify women (≥18 years of age) in Alberta, Canada, with IBD who delivered a baby between 2006 and 2009 inclusive. Women without IBD were randomly sampled and matched in a 3:1 ratio to IBD cases by age at conception (±1 year). Odds ratios of gestational diabetes, preterm birth, low birth weight, cesarean section, and neonatal intensive care unit admission were calculated.

RESULTS

One hundred and sixteen IBD patients were age-matched to 381 pregnant women without IBD. Gestational diabetes, preterm birth, and cesarean section were more common in women with IBD compared with controls (6.9 versus 1.8%, p = 0.03; 12.9 versus 0.3%, p < 0.0001; 43.1 versus 21.0%, p = 0.009, respectively). On multivariate analysis, women with IBD were independently more likely to have gestational diabetes (odds ratio [OR] = 4.3; 95% confidence interval [CI] 1.2-16.3), preterm birth (OR = 19.7, 95% CI 2.2-173.9), and to deliver by cesarean section (OR = 2.7, 95% CI 1.6-4.6) after adjusting for age and smoking status.

CONCLUSION

Intrapartum corticosteroid use significantly increases the risk of gestational diabetes in women with IBD. Furthermore, IBD patients are at higher risk of preterm delivery and are more likely to undergo cesarean section compared with a healthy age-matched population. The finding of a higher risk of gestational diabetes is a novel finding not previously reported in the IBD literature.

Smoking during pregnancy was up to 70% more common in the most deprived municipalities - a multilevel analysis of all singleton births during 2005-2010 in Finland

OBJECTIVE

We investigated whether there was an association between maternal smoking habits during pregnancy and municipality level deprivation defined based on education, income and unemployment after adjustment for individual level covariates, including socioeconomic status (SES), in Finland, a Nordic welfare state.

METHODS

Data were gathered from the Medical Birth Register and comprised all singleton births (n=337,876) during 2005-2010. To account for any correlation of women clustered within a municipality, we fitted generalized estimating equation (GEE) models.

RESULTS

In total, 15.3% of the women with singleton pregnancies smoked during pregnancy. After adjustment for individual level confounders, smoking during pregnancy was 5.4-fold higher among women with the lowest as compared with highest individual SES. Controlling for individual SES, age and year of birth, women living in municipalities defined as intermediately and highly deprived based on education were 53.7% (adjusted odds ratio [aOR] 1.537, 95% confidence interval [CI] 1.493-1.583) and 71.5% (aOR 1.715, 95% CI 1.647-1.785), respectively, more likely to smoke during pregnancy than women in the least deprived municipalities.

CONCLUSIONS

Individual SES is the strongest correlate of smoking during pregnancy but conditional on individual variables; lower municipality aggregate education is associated with up to 70% higher smoking prevalence.

Treatment of poor placentation and the prevention of associated adverse outcomes--what does the future hold?

Poor placentation, which manifests as pre-eclampsia and fetal growth restriction, is a major pregnancy complication. The underlying cause is a deficiency in normal trophoblast invasion of the spiral arteries, associated with placental inflammation, oxidative stress, and an antiangiogenic state. Peripartum therapies, such as prenatal maternal corticosteroids and magnesium sulphate, can prevent some of the adverse neonatal outcomes, but there is currently no treatment for poor placentation itself. Instead, management relies on identifying the consequences of poor placentation in the mother and fetus, with iatrogenic preterm delivery to minimise mortality and morbidity. Several promising therapies are currently under development to treat poor placentation, to improve fetal growth, and to prevent adverse neonatal outcomes. Interventions such as maternal nitric oxide donors, sildenafil citrate, vascular endothelial growth factor gene therapy, hydrogen sulphide donors, and statins address the underlying pathology, while maternal melatonin administration may provide fetal neuroprotection. In the future, these may provide a range of synergistic therapies for pre-eclampsia and fetal growth restriction, depending on the severity and gestation of onset.