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

Documento de consenso sobre tabaquismo y riesgo vascular

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

Placental pathology and neonatal morbidity: exploring the impact of gestational age at birth

AIM

To evaluate placental pathology in term and post-term births, investigate differences in clinical characteristics, and assess the risk of adverse neonatal outcome.

METHODS

This prospective observational study included 315 singleton births with gestational age (GA) > 36 weeks + 6 days meeting the local criteria for referral to placental histopathologic examination. We applied the Amsterdam criteria to classify the placentas. Births were categorized according to GA; early-term (37 weeks + 0 days to 38 weeks + 6 days), term (39 weeks + 0 days to 40 weeks + 6 days), late-term (41 weeks + 0 days to 41 weeks + 6 days), and post-term births (≥ 42 weeks + 0 days). The groups were compared regarding placental pathology findings and clinical characteristics. Adverse neonatal outcomes were defined as 5-minute Apgar score < 7, umbilical cord artery pH < 7.0, admission to the neonatal intensive care unit or intrauterine death. A composite adverse outcome included one or more adverse outcomes. The associations between placental pathology, adverse neonatal outcomes, maternal and pregnancy characteristics were evaluated by logistic regression analysis.

RESULTS

Late-term and post-term births exhibited significantly higher rates of histologic chorioamnionitis (HCA), fetal inflammatory response, clinical chorioamnionitis (CCA) and transfer to neonatal intensive care unit (NICU) compared to early-term and term births. HCA and maternal smoking in pregnancy were associated with adverse outcomes in an adjusted analysis. Nulliparity, CCA, emergency section and increasing GA were all significantly associated with HCA.

CONCLUSIONS

HCA was more prevalent in late and post-term births and was the only factor, along with maternal smoking, that was associated with adverse neonatal outcomes. Since nulliparity, CCA and GA beyond term are associated with HCA, this should alert the clinician and elicit continuous intrapartum monitoring for timely intervention.

Inequality in smoking and related risk factors for smoking in expectant mothers - a nationwide Danish register-based study

AIMS

Foetuses exposed to smoking during pregnancy are disadvantaged due to numerous adverse obstetric outcomes. This study aimed to examine 1) inequality in maternal smoking between subgroups of pregnant women and 2) significant risk factors of maternal smoking.

METHODS

Data were collected from Danish registries. Trends in maternal smoking within each study period, T1 (2000-2002) and T2 (2014-2016), were investigated by Poisson regression calculating prevalence proportion ratios, and trends between study periods were studied by adding an interaction term. The significance of risk factors for maternal smoking (low age, low education, living alone and having a moderate/severe mental health condition) were studied by interaction analysis on the additive scale.

RESULTS

The prevalence of maternal smoking decreased from 21% in 2000 to 7% in 2016. Decreases were found in all subgroups of maternal age, cohabitation status, educational level and mental health condition. However, large differences in smoking prevalence between subgroups were found, and inequality in maternal smoking increased from 2000 to 2016. The probability of maternal smoking increased with the addition of risk factors, and positive additive interactions were found for almost all combinations of multiple risk factors.

CONCLUSIONS

Our results provide knowledge on risk factors and increasing levels of inequality in maternal smoking which points to a need for targeted interventions in relation to maternal smoking for subgroups of pregnant women in future smoking cessation programmes and in antenatal care.

A systematic review of interventions to increase the use of smoking cessation services for women who smoke during pregnancy

BACKGROUND

Although many pregnant women accept referrals to stop-smoking support, the uptake of appointments often remains low.

AIM

The aim was to review the success of interventions to increase the uptake of external stop-smoking appointments following health professional referrals in pregnancy.

MATERIALS AND METHODS

Embase, PubMed, Cochrane Central Register of Controlled Trials, Scopus and CINAHL were searched in February 2023 for studies with interventions to increase the uptake rates of external stop-smoking appointments among pregnant women who smoke. Eligible studies included randomised, controlled, cluster-randomised, quasi-randomised, before-and-after, interrupted time series, case-control and cohort studies. Cochrane tools assessing for bias and Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were followed.

RESULTS

Two before-and-after studies were included, including a combined total of 1996 women who smoked during pregnancy. Both studies had a serious risk of bias, and meta-analysis was not possible due to heterogeneity. One study testing carbon monoxide monitors and opt-out referrals showed increased uptake of external stop-smoking appointments, health professional referrals and smoking cessation rates compared to self-identified smoking status and opt-in referrals. Results were limited in the second study, which used carbon monoxide monitors, urinary cotinine levels and self-disclosed methods to identify the smoking status with opt-out referrals. Only post-intervention data were available on the uptake of appointments to external stop-smoking services. The number of health professional referrals increased, but change in smoking cessation rates was less clear.

CONCLUSIONS

There is insufficient evidence to inform practice regarding strategies to increase the uptake of external stop-smoking appointments by women during pregnancy.

Perinatal Health Outcomes Across Rural and Nonrural Counties Within a Single Health System Catchment

Background

Perinatal health outcomes are influenced by a variety of socioeconomic, behavioral, and economic factors that reduce access to health services. Despite these observations, rural communities continue to face barriers, including a lack of resources and the fragmentation of health services.

Objective

To evaluate patterns in health outcomes, health behaviors, socioeconomic vulnerability, and sociodemographic characteristics across rural and nonrural counties within a single health system catchment area.

Methods

Socioeconomic vulnerability metrics, health care access as determined by licensed provider metrics, and behavioral data were obtained from FlHealthCHARTS.gov and the County Health Rankings. County-level birth and health data were obtained from the Florida Department of Health. The University of Florida Health Perinatal Catchment Area (UFHPCA) was defined as all Florida counties where ≥5% of all infants were delivered at Shands Hospital between June 2011 and April 2017.

Results

The UFHPCA included 3 nonrural and 10 rural counties that represented more than 64,000 deliveries. Nearly 1 in 3 infants resided in a rural county, and 7 out of 13 counties did not have a licensed obstetrician gynecologist. Maternal smoking rates (range 6.8%-24.8%) were above the statewide rate (6.2%). Except for Alachua County, breastfeeding initiation rates (range 54.9%-81.4%) and access to household computing devices (range 72.8%-86.4%) were below the statewide rate (82.9% and 87.9%, respectively). Finally, we found that childhood poverty rates (range 16.3%-36.9%) were above the statewide rate (18.5%). Furthermore, risk ratios suggested negative health outcomes for residents of counties within the UFHPCA for each measure, except for infant mortality and maternal deaths, which lacked sample sizes to adequately test.

Conclusions

The health burden of the UFHPCA is characterized by rural counties with increased maternal death, neonatal death, and preterm birth, as well as adverse health behaviors that included increased smoking during pregnancy and lower levels of breastfeeding relative to nonrural counties. Understanding perinatal health outcomes across a single health system has potential to not only estimate community needs but also facilitate planning of health care initiatives and interventions in rural and low-resource communities.

Prenatal smoke (Nicotine) exposure and offspring's metabolic disease susceptibility in adulthood

Exposure to smoking (nicotine) during pregnancy not only directly affects fetal development, but also increases susceptibility to metabolic diseases in adulthood, but the mechanism of action remains unclear. Here, we review epidemiological and laboratory studies linking these relationships. In addition to the direct effect of nicotine on the fetus, intrauterine neuroendocrine-metabolic programming mediated by maternal glucocorticoid overexposure also plays an important role, involving glucocorticoid-insulin-like growth factor 1 (GC-IGF1) axis, hypothalamic-pituitary-adrenal (HPA) axis, renin-angiotensin system (RAS) and other endocrine systems. Epigenetics is involved in intrauterine neuroendocrine-metabolic programming, metabolic disease susceptibility and multigenerational inheritance. There are "two programming" and "two strikes" mechanisms for the occurrence of fetal-originated metabolic diseases in adulthood. These innovative research summaries and academic viewpoints provide experimental and theoretical basis for systematically elucidating the occurrence and development of fetal-originated metabolic diseases.

Tobacco use during pregnancy

The use of tobacco during pregnancy is the leading preventable cause of pregnancy complications and adverse birth outcomes. In high-income countries, around one in 10 pregnant women smokes tobacco, while smokeless tobacco is the primary form of tobacco used in many low- and middle-income countries. Although the risk of tobacco-related harms can be reduced substantially if mothers cease smoking in the first trimester of pregnancy, the proportion of women who successfully quit smoking during pregnancy remains modest. Psychosocial interventions are first-line treatment, with some high-quality evidence showing that counselling is effective in promoting smoking cessation among pregnant women. There is insufficient evidence regarding the efficacy and safety of smoking cessation pharmacotherapies when used during pregnancy, although in some countries nicotine replacement therapy is recommended for pregnant women who have been unable to quit without pharmacological assistance. E-cigarettes are increasingly being used as a smoking cessation aid in the general population of smokers, but more research is needed to determine if e-cigarettes are a safe and effective treatment option for pregnant women.

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.

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

Background:

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

Objective:

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

Methods:

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

Results:

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

Conclusions:

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

Association between adverse pregnancy outcomes and preceding risk factors: a cross-sectional study from Nashik District, India

Background

The preconception phase of women’s life cycle is critical but comparatively ignored. The presence of health risks is judged as hazardous to the wellbeing of women and their offspring. This study aimed to estimate the prevalence of various pregnancy outcomes and assess the association between certain risk factors and adverse outcomes.

Methods

As a part of a preconception care intervention project, a baseline survey was conducted in four blocks of Nashik District, India. In this population-based cross-sectional analytical study, we compared cases in the study group (randomly selected one tribal and one non-tribal block) with those of the control group (one tribal and one non-tribal block). A comparison was also made between the tribal and non-tribal blocks in each group. All women who had a pregnancy outcome in the preceding 12 months (01 April 2017 to 31 March 2018) were interviewed. Trained Accredited Social Health Activists conducted the survey under the direct supervision of Auxiliary Nurse Midwives and Medical Officers. Multivariate analysis was carried out to find the adjusted prevalence ratio of having a particular adverse outcome because of the prespecified potential risk factors.

Results

A total of 9307 women participated in the study. The prevalence of adverse pregnancy outcomes was as follows: abortion in 4.1%, stillbirth in 1.7%, preterm birth in 4.1%, low birth weight in 13.2%, and congenital physical defect in 2.8%. Prevalence of parental consanguinity, pre-existing maternal illness at conception, heavy work during the last six months of pregnancy, tobacco consumption, alcohol consumption, direct exposure to pesticides and domestic violence during pregnancy was 18.5, 2.2, 18.7, 5.6, 0.5, 2.3, and 0.8% respectively. Risk factors associated with abortion included pre-existing illness and heavy work in the last six months of the pregnancy. Consanguinity, tobacco consumption during pregnancy and pre-existing illness were identified as risk factors for stillbirth. Significant risk factors of low birth weight were heavy work in the last six months of pregnancy, pre-existing illness and residence in a tribal area.

Conclusion

There is a need to emphasize on maternal behaviour, including tobacco consumption, and heavy work during pregnancy, as well as on parental consanguinity and pre-existing maternal illnesses, in order to achieve the best possible pregnancy outcomes.

Association of Prenatal Exposure to Maternal Drinking and Smoking With the Risk of Stillbirth

IMPORTANCE

Prenatal smoking is a known modifiable risk factor for stillbirth; however, the contribution of prenatal drinking or the combination of smoking and drinking is uncertain.

OBJECTIVE

To examine whether prenatal exposure to alcohol and tobacco cigarettes is associated with the risk of stillbirth.

DESIGN, SETTING, AND PARTICIPANTS

The Safe Passage Study was a longitudinal, prospective cohort study with data collection conducted between August 1, 2007, and January 31, 2015. Pregnant women from Cape Town, South Africa, and the Northern Plains region of the US were recruited and followed up throughout pregnancy. Data analysis was performed from November 1, 2018, to November 20, 2020.

EXPOSURE

Maternal consumption of alcohol and tobacco cigarettes in the prenatal period.

MAIN OUTCOMES AND MEASURES

The main outcomes were stillbirth, defined as fetal death at 20 or more weeks' gestation, and late stillbirth, defined as fetal death at 28 or more weeks' gestation. Self-reported alcohol and tobacco cigarette consumption was captured at the recruitment interview and up to 3 scheduled visits during pregnancy. Participants were followed up during pregnancy to obtain delivery outcome.

RESULTS

Of 11663 pregnancies (mean [SD] gestational age at enrollment, 18.6 [6.6] weeks) in 8506 women for whom the pregnancy outcome was known by 20 weeks' gestation or later and who did not terminate their pregnancies, there were 145 stillbirths (12.4 per 1000 pregnancies) and 82 late stillbirths (7.1 per 1000 pregnancies). A total of 59% of pregnancies were in women from South Africa, 59% were in multiracial women, 23% were in White women, 17% were in American Indian women, and 0.9% were in women of other races. A total of 8% were older than 35 years. In 51% of pregnancies, women reported no alcohol or tobacco cigarette exposure (risk of stillbirth, 4 per 1000 pregnancies). After the first trimester, 18% drank and smoked (risk of stillbirth, 15 per 1000 births), 9% drank only (risk of stillbirth, 10 per 1000 pregnancies), and 22% smoked only (risk of stillbirth, 8 per 1000 pregnancies). Compared with the reference group (pregnancies not prenatally exposed or without any exposure after the first trimester), the adjusted relative risk of late stillbirth was 2.78 (98.3% CI, 1.12-6.67) for pregnancies prenatally exposed to drinking and smoking, 2.22 (98.3% CI, 0.78-6.18) for pregnancies prenatally exposed to drinking only after the first trimester, and 1.60 (98.3% CI, 0.64-3.98) for pregnancies prenatally exposed to smoking only after the first trimester. The adjusted relative risk for all stillbirths was 1.75 (98.3% CI, 0.96-3.18) for dual exposure, 1.26 (98.3% CI, 0.58-2.74) for drinking only, and 1.27 (98.3% CI, 0.69-2.35) for smoking only compared with the reference group.

CONCLUSIONS AND RELEVANCE

These results suggest that combined drinking and smoking after the first trimester of pregnancy, compared with no exposure or quitting before the end of the first trimester, may be associated with a significantly increased risk of late stillbirth.

Behavioral Smoking Cessation Counseling During Pregnancy: A Cost-Effectiveness Analysis

OBJECTIVE

To examine the cost effectiveness of using behavioral smoking cessation counseling during pregnancy.

METHODS

We designed a decision-analytic model using TreeAge Pro 2020 software to compare the cost effectiveness and outcomes among women who received behavioral smoking cessation counseling compared with women who received usual care during pregnancy. We used a theoretical cohort of 285,000 women, the approximate number of pregnant women who smoke each year in the United States. Outcomes included maternal abstinence from smoking, fetal growth restriction, stillbirth, preterm delivery, neonatal death, and cerebral palsy, in addition to cost and quality-adjusted life-years (QALYs) for both the woman and the neonate. All model inputs were derived from the literature, and a willingness-to-pay threshold was set at $100,000 per QALY. Sensitivity analyses were performed to determine the robustness of baseline assumptions.

RESULTS

In our theoretical cohort, behavioral smoking cessation counseling compared with usual care was associated with 9,019 additional women stopping smoking during pregnancy (34,604 vs 25,585). Smoking cessation counseling also resulted in 911 fewer cases of fetal growth restriction, 20 fewer stillbirths, 250 fewer preterm deliveries, 11 fewer neonatal deaths, and one less case of cerebral palsy. Using behavioral smoking cessation counseling interventions during pregnancy led to better outcomes despite higher costs, with an incremental cost-effectiveness ratio of $71,658 per QALY, which was below our willingness-to-pay threshold of $100,000 per QALY, making the intervention cost effective. Sensitivity analyses demonstrated that the counseling intervention was cost effective at probabilities of smoking cessation greater than 11.6% (baseline input: 12.1%) or the cost of the behavioral intervention was less than $475.21 (baseline input: $368.78).

CONCLUSION

Behavioral smoking cessation counseling during pregnancy was associated with fewer adverse neonatal outcomes and was cost effective. Increasing utilization of such interventions and increasing insurance coverage of this care are important initiatives to improve outcomes in this at-risk population.

Lifestyle Habits among Pregnant Women in Denmark during the First COVID-19 Lockdown Compared with a Historical Period-A Hospital-Based Cross-Sectional Study

The first national lockdown in Denmark due to the COVID-19 pandemic was declared on 11 March 2020. From this date, national restrictions were imposed. We aimed to assess the potential influence of this first nationwide lockdown on exercise, alcohol consumption, and smoking in early pregnancy. Using a cross-sectional study based on routinely collected patient-reported data, we compared the lifestyle habits of women who were pregnant during the first phase of the pandemic (COVID-19 group) (n = 685) with those of women who were pregnant the year before (Historical group) (n = 787). We found a reduction in any exercise (PR = 0.91, 95% CI (0.84 to 0.99), in adherence to national recommendations of exercise (PR = 0.89, 95% CI (0.80 to 0.99), in cycling (15% vs. 28%, p < 0.0001), and swimming (0.3% vs. 3%, p = 0.0002) in the COVID-19 group compared with the Historical group. The prevalence of binge drinking was reduced in the COVID-19 group compared with the Historical group (PR = 0.80, 95% CI (0.68 to 0.93). In contrast, the prevalence of any weekly alcohol consumption and smoking cessation during pregnancy was similar between groups. Our findings indicate that national restrictions due to the COVID-19 pandemic influenced the lifestyle habits of pregnant women and should be addressed in antenatal counseling.

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.

Attention-deficit/hyperactivity disorder and smoking habits in pregnant women

Background

Attention-deficit/hyperactivity disorder (ADHD) has been associated with an increased risk of tobacco smoking, and more difficulties with smoking cessation compared to non-ADHD individuals. Women with ADHD may therefore show elevated rates of smoking during pregnancy.

Aims

To examine the association between ADHD and smoking habits among pregnant women in Sweden and Norway.

Methods

Women pregnant for the first time were identified in Sweden (n = 622,037), and Norway (n = 293,383), of which 1.2% (n = 7,444), and 1.7% (n = 4,951) were defined as having ADHD, respectively. Data on smoking habits were collected early and late in pregnancy.

Results

In Sweden, ADHD was associated with an increased risk of smoking early in pregnancy, adjusted risk ratio (adjRR) 2.69 (95% confidence interval, 2.58–2.81), and late in pregnancy, adjRR 2.95 (2.80–3.10). Similar findings were observed in the Norwegian data, early in pregnancy, adjRR 2.31 (2.21–2.40), and late in pregnancy, adjRR 2.56 (2.42–2.70). Women with ADHD were more likely to continue smoking during pregnancy, compared to women without ADHD, both in Sweden adjRR 1.13 (1.10–1.17), and in Norway, adjRR 1.16 (1.12–1.20). Having a sibling diagnosed with ADHD was associated with an increased risk of smoking early and late in pregnancy, in both Sweden and Norway.

Conclusions

Women with ADHD are considerably more likely to smoke early and late in (their first) pregnancy and are less likely to stop smoking between the two time points. Smoking, early and late in pregnancy, co-aggregates in families with ADHD. Smoking prevention and intervention programs should be targeted towards women with ADHD, specifically during their childbearing years, to ensure better mother and child outcomes.

Healthcare factors associated with the risk of antepartum and intrapartum stillbirth in migrants in Western Australia (2005-2013): A retrospective cohort study

BACKGROUND

Migrant women, especially from Indian and African ethnicity, have a higher risk of stillbirth than native-born populations in high-income countries. Differential access or timing of ANC and the uptake of other services may play a role. We investigated the pattern of healthcare utilisation among migrant women and its relationship with the risk of stillbirth (SB)-antepartum stillbirth (AnteSB) and intrapartum stillbirth (IntraSB)-in Western Australia (WA).

METHODS AND FINDINGS

A retrospective cohort study using de-identified linked data from perinatal, birth, death, hospital, and birth defects registrations through the WA Data Linkage System was undertaken. All (N = 260,997) non-Indigenous births (2005-2013) were included. Logistic regression analysis was used to estimate odds ratios and 95% CI for AnteSB and IntraSB comparing migrant women from white, Asian, Indian, African, Māori, and 'other' ethnicities with Australian-born women controlling for risk factors and potential healthcare-related covariates. Of all the births, 66.1% were to Australian-born and 33.9% to migrant women. The mean age (years) was 29.5 among the Australian-born and 30.5 among the migrant mothers. For parity, 42.3% of Australian-born women, 58.2% of Indian women, and 29.3% of African women were nulliparous. Only 5.3% of Māori and 9.2% of African migrants had private health insurance in contrast to 43.1% of Australian-born women. Among Australian-born women, 14% had smoked in pregnancy whereas only 0.7% and 1.9% of migrants from Indian and African backgrounds, respectively, had smoked in pregnancy. The odds of AnteSB was elevated in African (odds ratio [OR] 2.22, 95% CI 1.48-2.13, P < 0.001), Indian (OR 1.64, 95% CI 1.13-2.44, P = 0.013), and other women (OR 1.46, 95% CI 1.07-1.97, P = 0.016) whereas IntraSB was higher in African (OR 5.24, 95% CI 3.22-8.54, P < 0.001) and 'other' women (OR 2.18, 95% CI 1.35-3.54, P = 0.002) compared with Australian-born women. When migrants were stratified by timing of first antenatal visit, the odds of AnteSB was exclusively increased in those who commenced ANC later than 14 weeks gestation in women from Indian (OR 2.16, 95% CI 1.18-3.95, P = 0.013), Māori (OR 3.03, 95% CI 1.43-6.45, P = 0.004), and 'other' (OR 2.19, 95% CI 1.34-3.58, P = 0.002) ethnicities. With midwife-only intrapartum care, the odds of IntraSB for viable births in African and 'other' migrants (combined) were more than 3 times that of Australian-born women (OR 3.43, 95% CI 1.28-9.19, P = 0.014); however, with multidisciplinary intrapartum care, the odds were similar to that of Australian-born group (OR 1.34, 95% CI 0.30-5.98, P = 0.695). Compared with Australian-born women, migrant women who utilised interpreter services had a lower risk of SB (OR 0.51, 95% CI 0.27-0.96, P = 0.035); those who did not utilise interpreters had a higher risk of SB (OR 1.20, 95% CI 1.07-1.35, P < 0.001). Covariates partially available in the data set comprised the main limitation of the study.

CONCLUSION

Late commencement of ANC, underutilisation of interpreter services, and midwife-only intrapartum care are associated with increased risk of SB in migrant women. Education to improve early engagement with ANC, better uptake of interpreter services, and the provision of multidisciplinary-team intrapartum care to women specifically from African and 'other' backgrounds may reduce the risk of SB in migrants.

Impact of Maternal Smoking on the Onset of Breastfeeding versus Formula Feeding: A Cross-Sectional Study

This study sought to estimate the prevalence of maternal smoking and its association with exclusive breastfeeding vs. formula feeding. A cross-sectional study was performed on postpartum women at a public hospital in Spain, between January and August 2018. The main variables studied were their age, level of study, smoking habits, and chosen mode of infant feeding. In total, 948 postpartum women were included. Of these, 12.45% were smokers who smoked a mean of 7.23 cigarettes/day. Among the group of smokers, the probability of feeding the newborns with formula milk was multiplied by 2.32 ([95%CI 1.50-3.58] p < 0.001). When stratifying tobacco use into mild, moderate and severe, we found a statistically significant dose-response pattern. These associations and their statistical significance were maintained when adjusting by age and level of study. In conclusion, in the group of postpartum mothers who smoked, the probability of feeding the newborns with formula milk doubled. Our data highlight the need to improve health education programs in women of childbearing age, especially during pregnancy.

Prevalence and predictors of maternal smoking prior to and during pregnancy in a regional Danish population: a cross-sectional study

BACKGROUND

Maternal smoking is still a major public health problem posing the risk of several negative health outcomes for both the pregnant woman and her offspring. The prevalence of maternal smoking in Denmark and other high-income countries has decreased continuously since the 1980s, and a prevalence below 10% of women who continue to smoke during pregnancy has been reported in studies after 2010. Previous studies have shown that low socioeconomic status is associated with maternal smoking. Information from the Danish Birth Register about maternal smoking shows that the prevalence of women who report to smoke in pregnancy has decreased continuously with 23.3% who reported ever smoking in pregnancy in 2000, 12.9% in 2010 and 9.0% in 2017. The aim of this study was to estimate the prevalence of maternal smoking at the time of conception and at 20 weeks of gestation in a regional Danish population, to describe differences in maternal characteristics among smokers, quitters and never-smokers, and to estimate predictors of smoking at the time of conception.

METHODS

A cross-sectional study was conducted among pregnant women receiving antenatal care at the Department of Obstetrics, Zealand University Hospital, Denmark from August 2015 to March 2016 (n = 566). The main outcome was smoking at the time of conception and at 20 weeks of gestation. The questionnaire also collected information about maternal, health-related and sociodemographic characteristics. Descriptive analysis was conducted, and multivariate logistic regression analysis was used to assess the potential associated predictors (adjusted odds ratio).

RESULTS

The prevalence of self-reported smoking at the time of conception was 16% (n = 90) and 6% smoked at 20 weeks of gestation (n = 35), as 61% of smokers quit smoking during early pregnancy. Multiple logistic regression analysis showed that significant predictors for smoking at conception were the socioeconomic factors; ≤12 years of education, shift work and being unemployed.

CONCLUSION

The prevalence of self-reported maternal smoking in this regional Danish population of pregnant women is lower than seen in previous studies. However, predictors for smoking at the time of conception remain to be factors of low socioeconomic status confirming a social inequality in maternal smoking. Women at risk of smoking during pregnancy must be identified in early pregnancy or even before pregnancy and be offered interventions to help them quit smoking.

Stillbirth in the African Great Lakes region: A pooled analysis of Demographic and Health Surveys

Background

The aim of this study was to estimate the rate and predisposing factors associated with stillbirth in the African Great Lakes region (Burundi, Congo Democratic Republic, Kenya, Rwanda, Tanzania and Uganda).

Methods and findings

Cross-sectional data from the most recent Demographic and Health Surveys (DHS) of countries in the African Great Lakes region were used in this study. DHS from Congo Democratic Republic was not included in the analyses because data was not collected for stillbirth in the country survey. A pooled sample of 57046 pregnancies of 7+ months’ duration and 1002 stillbirths were included in the final analysis. The analyses were restricted to stillbirths reported in the 5 years preceding the surveys. Stillbirth was defined as foetal death in the third trimester (≥ 28 weeks’ gestation). Multilevel logistic regression analyses that adjusted for cluster and survey weights were used to determine the factors associated with stillbirth in the Africa Great Lakes region. Health service variables and maternal medical condition variables were not included in the analysis because DHS do not collect data on these variables for pregnancies that did not result in a live birth. Burundi had the highest stillbirth rate per 1000 births [23% (95% CI: 20, 25)] within the region. Factors associated with stillbirth across the region were: no schooling [1.85 (95%Cl: 1.44, 2.38)] and primary education [1.64 (1.32, 2.05)], advanced maternal age [2.39 (95% CI: 1.59, 3.59)], smoking [1.99 (95% CI: 1.19, 3.32)] and drinking water from unimproved sources [1.18 (95% CI: 1.01, 1.37)].

Conclusion

To achieve Every Newborn Action Plan (ENAP) stillbirth target of 12 per 1000 births or less by 2030, policy interventions to prevent stillbirth should focus on promoting community-based socio-educational programmes which encourages a healthy lifestyle especially among uneducated women in the advanced age spectrum.

Changes in the smoking behavior of pregnant women andtheir family members during pregnancy: A cross-sectional study in China

INTRODUCTION

Studies regarding the changes in smoking behavior of pregnant women have been mostly conducted in high income countries but rarely in China. This study thus focused on investigating the changes in smoking behavior among pregnant women and their family members in China, both before and during pregnancy.

METHODS

A cross-sectional study was carried out at nine Women and Children’s Hospitals in Shanghai, China, in 2014. A total of 2831 gestational households were recruited. The chi-squared test, paired sample t-test and logistical regression analysis were used during statistical analysis.

RESULTS

The prevalence of smoking for all household members significantly declined during pregnancy: 76.2% of the pregnant women, 19.2% of their husbands and 14.0% of other family members quit smoking entirely. The average daily cigarette consumption rate decreased from 5.9 to 0.9 among pregnant women, 11.4 to 9.5 for husbands, and 11.4 to 9.5 for other family members (paired sample t-test, p<0.001). The likelihood that husbands continued smoking during pregnancy was significantly lower for those with a shorter history of smoking, had a lower daily cigarette consumption rate and a household registration in Shanghai.

CONCLUSIONS

The prevalence of smoking among pregnant women, husbands and other family members significantly declines during pregnancy. Thus, pregnancy is most likely a key period in which to provide families with health education regarding the effects of smoking, both during the pregnancy period and in general. Intervention programs designed to reduce smoking among husbands during pregnancy should focus on those with a long history of smoking, a high rate of daily cigarette consumption, and those with household registration not in Shanghai.

Adverse Pregnancy Outcomes among Adolescents in Northwest Russia: A Population Registry-Based Study

This study aimed to assess whether adolescents have an increased risk of adverse pregnancy outcomes (APO) compared to adult women. We used data on 43,327 births from the population-based Arkhangelsk County Birth Registry, Northwest Russia, for 2012-2014. The perinatal outcomes included stillbirth, preterm birth (<37 and <32 weeks), low and very low birthweight, 5 min Apgar score <7 and <4, perinatal infections, and the need for neonatal transfer to a higher-level hospital. Multivariable logistic regression was applied to assess the associations between age and APO. Altogether, 4.7% of deliveries occurred in adolescents. Both folic acid intake and multivitamin intake during pregnancy were more prevalent in adults. Adolescents were more likely to be underweight, to smoke, and to have infections of the kidney and the genital tract compared to adult women. Compared to adults, adolescents were at lower risk of low birthweight, a 5 min Apgar score <7, and need for neonatal transfer. Adolescents had no increased risk of other APO studied in the adjusted analysis, suggesting that a constellation of other factors, but not young age per se, is associated with APO in the study setting.

Association between maternal sleep practices and late stillbirth - findings from a stillbirth case-control study

Objective

To report maternal sleep practices in women who experienced a stillbirth compared with controls with ongoing live pregnancies at similar gestation.

Design

Prospective case‐control study.

Setting

Forty‐one maternity units in the United Kingdom.

Population

Women who had a stillbirth after ≥ 28 weeks’ gestation (n = 291) and women with an ongoing pregnancy at the time of interview (n = 733).

Methods

Data were collected using an interviewer‐administered questionnaire that included questions on maternal sleep practices before pregnancy, in the four weeks prior to, and on the night before the interview/stillbirth.

Main outcome measures

Maternal sleep practices during pregnancy.

Results

In multivariable analysis, supine going‐to‐sleep position the night before stillbirth had a 2.3‐fold increased risk of late stillbirth [adjusted Odds Ratio (aOR) 2.31, 95% CI 1.04–5.11] compared with the left side. In addition, women who had a stillbirth were more likely to report sleep duration less than 5.5 hours on the night before stillbirth (aOR 1.83, 95% CI 1.24–2.68), getting up to the toilet once or less (aOR 2.81, 95% CI 1.85–4.26), and a daytime nap every day (aOR 2.22, 95% CI 1.26–3.94). No interaction was detected between supine going‐to‐sleep position and a small‐for‐gestational‐age infant, maternal body mass index, or gestational age. The population‐attributable risk for supine going‐to‐sleep position was 3.7% (95% CI 0.5–9.2).

Conclusions

This study confirms that supine going‐to‐sleep position is associated with late stillbirth. Further work is required to determine whether intervention(s) can decrease the frequency of supine going‐to‐sleep position and the incidence of late stillbirth.

Tweetable abstract

Supine going‐to‐sleep position is associated with 2.3× increased risk of stillbirth after 28 weeks’ gestation.

Plain Language Summary

Stillbirth, the death of a baby before birth, is a tragedy for mothers and families. One approach to reduce stillbirths is to identify factors that are associated with stillbirth. There are few risk factors for stillbirth that can be easily changed, but this study is looking at identifying how mothers may be able to reduce their risk.

In this study, we interviewed 291 women who had a stillbirth and 733 women who had a live‐born baby from 41 maternity units throughout the UK. The mothers who had a stillbirth were interviewed as soon as practical after their baby died. Mothers who had a live birth were interviewed during their pregnancies at the same times in pregnancy as when the stillbirths occurred. We did not interview mothers who had twins or who had a baby with a major abnormality.

Mothers who went to sleep on their back had at least twice the risk of stillbirth compared with mothers who went to sleep on their left‐hand side. This study suggests that 3.7% of stillbirths after 28 weeks of pregnancy were linked with going to sleep lying on the back. This study also shows that the link between going‐to‐sleep position and late stillbirth was not affected by the duration of pregnancy after 28 weeks, the size of the baby, or the mother's weight. Women who got up to the toilet once or more at night had a reduced risk of stillbirth.

This is the largest of four similar studies that have all shown the same link between the position in which a mother goes to sleep and stillbirth after 28 weeks of pregnancy. Further studies are needed to see whether women can easily change their sleep position in late pregnancy and whether changing the position a mother goes to sleep in reduces stillbirth.

Tweetable abstract

Supine going‐to‐sleep position is associated with 2.3× increased risk of stillbirth after 28 weeks’ gestation.

This paper includes Author Insights, a video abstract available at https://vimeo.com/rcog/authorinsights14967

Negative Temperature Differential in Preterm Infants Less Than 29 Weeks Gestational Age: Associations With Infection and Maternal Smoking

BACKGROUND

Hypothermia is related to increased morbidity and mortality in very preterm infants; continuous temperature monitoring is necessary. Thermoregulation is limited in preterm infants.

OBJECTIVES

The purpose of the research was to assess and describe negative temperature differential (NTD) and assess the associations of NTD with infant demographic characteristics, medical history, and clinical events.

METHODS

An exploratory, case study design was used. Abdominal and foot temperature was measured every minute over the first 2 weeks of life in 22 preterm infants at less than 29 weeks gestational age.

RESULTS

All infants experienced NTD. Daily NTD in all infants across all study days ranged from 0 to 70.7%; 2-week mean NTD over all infants ranged from 7.3% to 38.5%. Four infants treated for late onset of infection had a higher NTD than 18 infants without infection (M = 27.8%, SD = 9.52 vs. M = 16.4%, SD = 5.34, p < .05). Although not statistically significant, higher mean percentage of NTD was noted in infants having early onset infection (24.1% vs. 16.4%), African American race (20.0% vs. 15.3%), and/or being born to a mother who smoked during pregnancy (26.6% vs. 16.7%).

DISCUSSION

A larger study is needed to examine associations between NTD and race, maternal smoking history, and infection. NTD might be used as a biomarker to guide acute clinical care and identify infants at risk for acute and chronic morbidity.