Does maternal smoking have a negative physiological effect on breastfeeding? The epidemiological evidence

Socioeconomic status and rates of breastfeeding in Australia: evidence from three recent national health surveys

OBJECTIVE

To investigate whether the relationship between socioeconomic status and breastfeeding initiation and duration changed in Australia between 1995 and 2004.

DESIGN AND SETTING

Secondary analysis of data from national health surveys (NHSs) conducted by the Australian Bureau of Statistics in 1995, 2001 and 2004-05. The Socio-Economic Indexes for Areas (SEIFA) classification was used as a measure of socioeconomic status.

MAIN OUTCOME MEASURES

Rates of initiation of breastfeeding; rates of breastfeeding at 3, 6 and 12 months.

RESULTS

Between the 1995 and 2004-05 NHSs, there was little change in overall rates of breastfeeding initiation and duration. In 2004-05, breastfeeding initiation was 87.8%, and the proportions of infants breastfeeding at 3, 6 and 12 months were 64.4%, 50.4% and 23.3%, respectively. In 1995, the odds ratio (OR) of breastfeeding at 6 months increased by an average of 13% (OR, 1.13 [95% CI, 1.07-1.19]) for each increase in SEIFA quintile; in 2001, the comparative increase was 21% (OR, 1.21 [95% CI, 1.12-1.30]); while in 2004-05, the comparative increase was 26% (OR, 1.26 [95% CI, 1.17-1.36]). Breastfeeding at 3 months and 1 year showed similar changes in ORs. There was little change in the ORs for breastfeeding initiation.

CONCLUSION

Although overall duration of breastfeeding remained fairly constant in Australia between 1995 and 2004-05, the gap between the most disadvantaged and least disadvantaged families has widened considerably over this period.

Infant feeding in Sweden: socio-demographic determinants and associations with adiposity in childhood and adolescence

Background

Recent reviews and meta-analyses conclude that breastfeeding constitutes a small but consistent protective effect against obesity or higher values of body mass index (BMI) in children, though in some studies this effect was weakened after adjustment for potential confounders. The aim of this study was to explore the socio-demographic determinants of the duration of breastfeeding in Sweden and the associations between breastfeeding duration and adiposity in childhood and adolescence.

Methods

This was a cross-sectional study of Swedish children. Height, weight and waist circumference were measured and the sum of five skin fold measurements were obtained in 1137 9- and 15-year old children. Breastfeeding data were retrospectively obtained from the medical records for 812 (71.4%) children. Multiple ordinal logistic regression was applied to study individual effects of the maternal characteristics on the duration of breastfeeding. The relationship between children's anthropometric characteristics and duration of breastfeeding was studied by multiple linear regression. Associations between the odds of being overweight or obese and the duration of breastfeeding were studied by multiple logistic regression. Both linear and logistic models were adjusted for children's age, gender, birth weight, maternal education and parental BMI in 1998 as well as maternal age and smoking status at childbirth.

Results

Maternal education was positively associated with the duration of breastfeeding in both 1983 and 1989. Non-smoking mothers were more likely to breastfeed longer than smokers in 1989 (OR = 1.9, 95%CI: 1.3, 3.0). Fifteen-year old children breastfed for shorter than 2 months had 1.2 kg/m² (95%CI: 0.1, 2.4) higher BMI, 3.2 cm (95%CI: 0.2, 6.2) higher waist circumference and 10.6 mm (95%CI: 1.7, 19.6) higher sum of five skin fold measurements compared to those breastfed for 6 months or longer when adjusted for children's characteristics and maternal characteristics in 1998. Adjustment for maternal age and smoking status at childbirth weakened these associations to non-significant levels (0.9 kg/m², 95%CI: -0.4, 2.1; 1.4 cm, 95%CI: -1.5, 4.4 and 5.1 mm, 95%CI: -4.0, 14.2, respectively). In the 9-year olds, the associations were less pronounced, but in the same direction. No trends between duration of breastfeeding and children's anthropometric characteristics were observed in any of the age groups.

Conclusion

Maternal education and smoking were significant predictors of breastfeeding duration in Sweden in the 1980s. Associations with measures of adiposity were observed only in 15-year old children between the children with shortest and longest breastfeeding duration, which were weakened after adjustment for maternal characteristics at childbirth.

Prenatal exposure to passive smoking and duration of breastfeeding in nonsmoking women: Krakow inner city prospective cohort study

INTRODUCTION

The relationship between tobacco smoking in pregnancy and breastfeeding is of public health importance. The present birth cohort study provided the opportunity to investigate whether the negative relationship between passive smoking measured by the cotinine concentrations in maternal blood at delivery and breastfeeding in postpartum could also be confirmed in nonsmoking mothers.

MATERIALS AND METHODS

The study sample included 441 healthy pregnant women who were recruited in the first and second trimester of pregnancy. Enrollment included only nonsmoking women of the age of 18-35 years with singleton pregnancies, without illicit drug use and free from chronic diseases. After delivery, breastfeeding duration was defined using the answers recorded in the interviews with mothers conducted every 3 months. An infant was considered to be fully breastfed when breast milk was the only source of nourishment. Any breastfeeding was defined as an infant's being fully breastfed or receiving both breast milk and formula, with or without solids. In the statistical analysis only total duration of breastfeeding up to 6 months was considered for both forms of breastfeeding. Subjects were categorized into environmental tobacco smoke (ETS) exposure groups according to maternal blood cotinine level at delivery or self-reported exposure to ETS during pregnancy.

RESULTS

The adjusted relative risk of discontinuation of any breastfeeding after infant's first 6 months was more than two times higher (OR = 2.42; 95% CI: 1.42-4.14) in women whose blood cotinine level at delivery was above 75th percentile of cotinine distribution (>0.15 ng/mL); the corresponding risk of discontinuation of full breastfeeding was OR = 1.71; 95% CI: 1.03-2.82. Estimated relative risk of discontinuation of any breastfeeding based on self-reported ETS was also significant but much less marked; the corresponding risk of discontinuation of full breastfeeding was insignificant.

CONCLUSION

The results obtained support the hypothesis that ETS may affect breastfeeding duration and support the avoidance of passive smoking as a necessary additional measure for breastfeeding promotion.

Which mothers smoke before, during and after pregnancy?

OBJECTIVE

To investigate the sociodemographic factors associated with cigarette smoking in women before, during and after pregnancy.

STUDY DESIGN

A 12-month longitudinal study.

METHOD

All eligible mothers at two public maternity hospitals in Perth, Australia were asked to participate in a study of infant feeding. While in hospital, participating mothers completed a self-administered baseline questionnaire. Follow-up telephone interviews were conducted at 4, 10, 16, 22, 32, 40 and 52 weeks. Data collected included sociodemographic, biomedical, hospital-related and psychosocial factors associated with the initiation and duration of breastfeeding.

RESULTS

A total of 587 (55%) mothers participated in the study. Thirty-nine percent of mothers reported smoking pre-pregnancy. Mothers who smoked were more likely to have a partner who smoked and to have consumed alcohol prior to pregnancy, and less likely to have attended antenatal classes. They were also less likely to have known how they were going to feed their baby before conception and likely to be more inclined to consider stopping breastfeeding before four months postpartum.

CONCLUSIONS

Having a partner (father of the newborn infant) who smoked and maternal alcohol consumption prenatally were factors associated with pre-pregnancy smoking. In addition, if a woman decided how she would feed her infant before the pregnancy occurred and intended to breastfeed for longer than four months she was less likely to smoke in the prenatal period. Having a father (of the newborn infant) who smoked during pregnancy continued to be a factor significantly associated with maternal smoking in the antenatal and postnatal period. Not attending antenatal classes and not intending to breastfeed for longer than four months were also factors associated with maternal smoking. At ten weeks postpartum being of Caucasian origin and having a low Iowa Infant Feeding Attitude Score were factors significantly associated with smoking postnatally.

Development of cocaine sensitization before pregnancy affects subsequent maternal retrieval of pups and prefrontal cortical activity during nursing

Pups are a highly rewarding stimulus for early postpartum rats. Our previous work supports this notion by showing that suckling activates the mesocorticolimbic system in mothers. In the present study, we tested whether development of behavioral sensitization to cocaine before pregnancy affects the neural response to pups during the early postpartum days (PD). Virgin rats were repeatedly administered cocaine for 14 days (15 mg kg(-1)) and withdrawn from treatment during breeding and pregnancy. The neural response to suckling was measured at PD 4-8 using blood-oxygen-level-dependent (BOLD) MRI or microdialysis. Our results show that BOLD activation in the medial prefrontal cortex (PFC), septum and auditory cortex was curtailed in cocaine-sensitized dams. No differences between cocaine sensitized and saline control dams were observed in the nucleus accumbens, olfactory structures, or in 48 additional major brain regions that were analyzed. Baseline, but not pup-stimulated, dopamine (DA) levels in the medial PFC were lower in cocaine-sensitized dams than in controls. When tested for maternal behaviors, cocaine-sensitized dams showed significantly faster retrieval of pups without changes in other maternal behaviors such as grouping, crouching and defending the nest. Taken together, the present findings suggest that maternal motivation to retrieve pups was enhanced by repeated cocaine exposure and withdrawal, a result reminiscent of 'cross-sensitization' between the drug and a natural reward. Changes in retrieval behavior in cocaine-sensitized mothers might be associated with a hypo-responsive medial PFC.

A systematic review of maternal obesity and breastfeeding intention, initiation and duration

Background

Breastfeeding behaviour is multifactorial, and a wide range of socio-cultural and physiological variables impact on a woman's decision and ability to breastfeed successfully. An association has been reported between maternal obesity and low breastfeeding rates. This is of public health concern because obesity is rising in women of reproductive age and the apparent association with increased artificial feeding will lead to a greater risk of obesity in children. The aim of this paper is to examine the relationship between maternal overweight and obesity and breastfeeding intention and initiation and duration.

Methods

A systematic review was conducted in January and February 2007, using the following databases: Medline, CINAHL and the Australian Breastfeeding Association's Lactation Resource Centre. Studies which have examined maternal obesity and infant feeding intention, initiation, duration and delayed onset of lactation were tabulated and summarised.

Results

Studies have found that obese women plan to breastfeed for a shorter period than normal weight women and are less likely to initiate breastfeeding. Of the four studies that examined onset of lactation, three reported a significant relationship between obesity and delayed lactogenesis. Fifteen studies, conducted in the USA, Australia, Denmark, Kuwait and Russia, have examined maternal obesity and duration of breastfeeding. The majority of large studies found that obese women breastfed for a shorter duration than normal weight women, even after adjusting for possible confounding factors.

Conclusion

There is evidence from epidemiological studies that overweight and obese women are less likely to breastfeed than normal weight women. The reasons may be biological or they may be psychological, behavioral and/or cultural. We urgently need qualitative studies from women's perspective to help us understand women in this situation and their infant feeding decisions and behaviour.

Violence against women and the perinatal period: the impact of lifetime violence and abuse on pregnancy, postpartum, and breastfeeding

Violence against women affects millions of women, including women who are pregnant or have recently given birth. During pregnancy, a woman's history of past abuse increases her risk of depression and posttraumatic stress disorder. And these increase the risk of pregnancy and neonatal complications. Women who have experienced past or current abuse are also at high risk for postpartum depression, which can affect their relationships with other adults and their babies. Violence against women can also affect women's ability to breastfeed, although abuse survivors often express an intention to breastfeed and are more likely to initiate breastfeeding than their nonabused counterparts. Current abuse, depression, posttraumatic stress disorder, social isolation, lack of social support, and cessation of breastfeeding all have negative health effects for mothers and babies.

Factors influencing breastfeeding rates in south-western Sydney

AIM

To explore the socio-demographic factors and other maternal characteristics that influence breastfeeding initiation rates. In particular, this paper aims to (i) estimate the rate of breastfeeding by maternal socio-demographic factors and other maternal characteristics at first well-baby visit; and (ii) investigate the relationship between breastfeeding rates and these maternal factors.

METHODS

Cross-sectional data were obtained for 9618 babies in south-western Sydney in New South Wales from the Ingleburn Baby Information Systems database from January 2000 to June 2004 and included information on breastfeeding status, socio-demographic factors and other maternal characteristics.

RESULTS

At first visit, 59.8% of mothers were breastfeeding. The factors that increased the risk for NOT breastfeeding on multivariate analysis were being Australian-born (OR=1.67, 95% CI 1.45-1.89, P<0.001), unmarried (OR=1.79, 95% CI 1.52-2.11, P<0.001), living in disadvantaged accommodation (OR=1.90, 95% CI 1.60-2.26, P<0.001), having lower levels of education (OR=1.88, 95% CI 1.38-2.54, P<0.001) and current smoking (OR=1.72, 95% CI 1.51-1.96, P<0.001).

CONCLUSION

The results from this large population-based study suggest that breastfeeding rates are significantly influenced by socio-demographic factors and maternal characteristics. Consequently, subgroups of the population 'at risk' for not breastfeeding can be identified and targeted for further strategies to promote breastfeeding.

Breastfeeding: factors associated with the continuation of breastfeeding, the current situation in Japan, and recommendations for further research

There are a number of research reports that address the various advantages that breastfeeding brings to mothers and children, as well as to families and society, and in addition to a number of physically positive effects, breastfeeding has an important role in terms of mental and psychological effects.Ninety-five % of mothers desire to breastfeed, which reflects social acceptance, but the actual breastfeeding rate of the first month after childbirth is 42%, which accounts for about a half of all mothers. Breastfeeding is a natural behavior, but it cannot be performed only by instinct, so mothers discontinue breastfeeding for various reasons. While these reasons for the discontinuation of breastfeeding have been studied in many countries, research regarding the usability of care to support breastfeeding is being conducted in other countries at a level that can be considered evidential, but not yet in Japan. In addition, the current situation is that breastfeeding is strongly promoted but the support provided remains inadequate for mothers who cannot breastfeed, regardless of whatever efforts they make. This article will review several factors associated with the continuation of breastfeeding and the current situation in Japan, with the intention of identifying desirable areas for further research.

Preventable newborn readmissions since passage of the Newborns' and Mothers' Health Protection Act

BACKGROUND

Congress passed the Newborns' and Mothers' Health Protection Act in 1996, reversing the trend of shorter newborn nursery lengths of stay. Hope existed that morbidities would lessen for this vulnerable population, but some reports indicate that the timeliness and quality of postdischarge care may have worsened in recent years.

OBJECTIVE

Our goal was to determine risk factors for the potentially preventable readmissions because of jaundice, dehydration, or feeding difficulties in the first 10 days of life in Pennsylvania since passage of the Newborns' and Mothers' Health Protection Act.

PATIENTS AND METHODS

Birth records from 407,826 newborns > or = 35 weeks' gestation from 1998 to 2002 were merged with clinical discharge records. A total of 2540 newborns rehospitalized for jaundice, dehydration, or feeding difficulties in the first 10 days of life were then compared with 5080 control infants. Predictors of readmission were identified by using multiple logistic regression analysis.

RESULTS

An unadjusted comparison of baseline characteristics revealed numerous predictors of readmission. Subsequent adjusted analysis revealed that Asian mothers, those 30 years of age or older, nonsmokers, and first-time mothers were more likely to have a readmitted newborn, as were those with diabetes and pregnancy-induced hypertension. For neonates, female gender and delivery via cesarean section were protective for readmission, whereas vacuum-assisted delivery, gestational age < 37 weeks, and nursery length of stay < 72 hours were predictors of readmission in the first 10 days of life.

CONCLUSIONS

Although readmissions for jaundice, dehydration, and feeding difficulties may be less common for some minority groups and Medicaid recipients in the era of the Newborns' and Mothers' Health Protection Act compared with nonminorities or privately insured patients, several predictors of newborn readmission have established associations with inexperienced parenting and/or breastfeeding difficulty. This is one indication that this well-intentioned legislation and current practice may not be sufficiently protecting the health of newborns and suggests that additional support for mothers and newborns during the vulnerable postdelivery period may be indicated.

Maternal cigarette smoking and breastfeeding duration

AIM

To examine the relationship between cigarette smoking and breastfeeding duration at 2 wk, 6 mo, and longer.

METHODS

Design. A 12-mo longitudinal study. Setting. Two public maternity hospitals in the Perth metropolitan area (Western Australia). Subjects. Eligible mothers of healthy newborn infants. Interventions. Participants completed a self-administered baseline questionnaire while in hospital or shortly after discharge. All women regardless of their chosen infant feeding method were followed up by telephone interview at 4, 10, 16, 22, 32, 40 and 52 wk postpartum. Main outcome measures. Prevalence of breastfeeding at 2 wk, 2 wk to 6 mo and >6 mo in women who smoked during pregnancy, and breastfeeding duration.

RESULTS

Women who smoked during pregnancy had a lower prevalence and shorter duration of breastfeeding than non-smoking mothers (28 vs 11 wk, 95% CI 8.3-13.7). This effect remained even after adjustment for age, education, income, father's smoking status, mother's country of birth, intended duration of breastfeeding >6 mo and birthweight (risk ratio 1.59, 95% CI 1.22-2.08).

CONCLUSION

Women who smoke during pregnancy are at greater risk of not achieving national and international targets for breastfeeding. Encouraging smoking cessation in the antenatal setting is an area for considerable public health gain.

Factors associated with breastfeeding at six months postpartum in a group of Australian women

BACKGROUND

Despite high levels of breastfeeding initiation in Australia, only 47 percent of women are breastfeeding (exclusively or partially) six months later, with marked differences between social groups. It is important to identify women who are at increased risk of early cessation of breastfeeding.

METHODS

Data from the three arms of a randomised controlled trial were pooled and analysed as a cohort using logistic regression to identify which factors predicted women continuing to feed any breast milk at six months postpartum. The original trial included 981 primiparous women attending a public, tertiary, women's hospital in Melbourne, Australia in 1999-2001. The trial evaluated the effect of two mid-pregnancy educational interventions on breastfeeding initiation and duration. In the 889 women with six month outcomes available, neither intervention increased breastfeeding initiation nor duration compared to standard care. Independent variables were included in the predictive model based on the literature and discussion with peers and were each tested individually against the dependent variable (any breastfeeding at six months).

RESULTS

Thirty-three independent variables of interest were identified, of which 25 qualified for inclusion in the preliminary regression model; 764 observations had complete data available. Factors remaining in the final model that were positively associated with breastfeeding any breast milk at six months were: a very strong desire to breastfeed; having been breastfed oneself as a baby; being born in an Asian country; and older maternal age. There was an increasing association with increasing age. Factors negatively associated with feeding any breast milk at six months were: a woman having no intention to breastfeed six months or more; smoking 20 or more cigarettes per day pre-pregnancy; not attending childbirth education; maternal obesity; having self-reported depression in the six months after birth; and the baby receiving infant formula while in hospital.

CONCLUSION

In addition to the factors commonly reported as being associated with breastfeeding in previous work, this study found a negative association between breastfeeding outcomes and giving babies infant formula in hospital, a high maternal body mass index, and self-reported maternal depression or anxiety in the six months after the baby was born. Interventions that seek to increase breastfeeding should consider focusing on women who wish to breastfeed but are at high risk of early discontinuation.

Which women stop smoking during pregnancy and the effect on breastfeeding duration

BACKGROUND

Cigarette smoking during pregnancy increases the risk of adverse pregnancy outcomes and women who quit smoking at this time are able to reduce the risk of low birth weight, preterm labour, spontaneous abortion and perinatal death. This study investigates the socio-demographic characteristics of pregnant women who stop smoking during pregnancy and the association between stopping smoking and breastfeeding duration.

METHODS

A 12 month longitudinal study was conducted in two public maternity hospitals in Perth, Australia between mid-September 2002 and mid-July 2003. While in hospital, participating mothers completed a self-administered baseline questionnaire. Follow up telephone interviews were conducted at 4, 10, 16, 22, 32, 40 and 52 weeks.

RESULTS

A total of 587 (55%) mothers participated in the study. Two hundred and twenty six (39%) mothers reported smoking prior to pregnancy and 77 (34%) of these stopped smoking during pregnancy. Women who were pregnant for the first time were twice as likely (OR = 2.05; 95% CI 1.047 - 4.03; p < 0.05) to quit smoking as multiparous women. Women who smoked more than 10 cigarettes per day were significantly less likely to quit smoking during pregnancy (OR = 0.36; 95% CI 0.18 - 0.69; p < 0.05). Women who consumed alcohol before pregnancy were three times more likely to quit smoking (OR = 2.58; 95% CI 1.00 - 6.66; p < 0.05). Quitting smoking during pregnancy was significantly associated with breastfeeding for longer than six months (OR = 3.70; 95% CI 1.55 - 8.83; p < 0.05).

CONCLUSION

Pregnancy is a time when many women are motivated to quit smoking and providing targeted smoking cessation interventions at this time, which take into account factors predictive of quitting smoking, are more likely to be successful.

Predictors of breastfeeding duration: evidence from a cohort study

OBJECTIVE

To report the duration of breastfeeding among a population of Australian women and to identify factors that are associated with the duration of full breastfeeding to 6 months and any breastfeeding to 12 months.

METHODS

Participants were 587 women who were recruited from 2 maternity hospitals in Perth and completed a baseline questionnaire just before or shortly after discharge from the hospital. Women were followed up by telephone interview at 4, 10, 16, 22, 32, 40, and 52 weeks postpartum. Data collected included sociodemographic, biomedical, hospital-related, and psychosocial factors associated with the initiation and the duration of breastfeeding. Cox's proportional hazards model was used to identify factors that were associated with the risk for discontinuing full breastfeeding before 6 months and any breastfeeding before 12 months.

RESULTS

At 6 months of age, fewer than one half of infants were receiving any breast milk (45.9%), and only 12% were being fully breastfed. By 12 months, only 19.2% of infants were still receiving any breast milk. Breastfeeding duration was independently, positively associated with maternal infant feeding attitudes and negatively associated with breastfeeding difficulties in the first 4 weeks, maternal smoking, introduction of a pacifier, and early return to work.

CONCLUSIONS

Relatively few women achieved the international recommendations for duration of full and overall breastfeeding. Women should receive anticipatory guidance while still in the hospital on how to prevent or manage common breastfeeding difficulties and should be discouraged from introducing a pacifier before 10 weeks, if at all. Improved maternity leave provisions and more flexible working conditions may help women to remain at home with their infants longer and/or to combine successfully breastfeeding with employment outside the home.

Developing an evidence base for policies and interventions to address health inequalities: the analysis of "public health regimes"

Systematic reviews have become an important methodology in the United Kingdom by which research informs health policy, and their use now extends beyond evidence-based medicine to evidence-based public health and, particularly, health inequalities policies. This article reviews the limitations of systematic reviews as stand-alone tools for this purpose and suggests a complementary approach to make better use of the evidence. That is, systematic reviews and other sources of evidence should be incorporated into a wider analytical framework, the public health regime (defined here as the specific legislative, social, political, and economic structures that have an impact on both public health and the appropriateness and effectiveness of public health interventions adopted). At the national level this approach would facilitate analysis at all levels of the policy framework, countering the current focus on individual interventions. It could also differentiate at the international level between those policies and interventions that are effective in different contexts and are therefore potentially generalizable and those that depend on particular conditions for success.

Breastfeeding duration and perinatal cigarette smoking in a population-based cohort

OBJECTIVES

We examined the association between breastfeeding duration and maternal smoking before, during, and after pregnancy.

METHODS

Data from the 2000-2001 Oregon Pregnancy Risk Assessment Monitoring System were used. Early weaning was defined as not breastfeeding at 10 weeks postpartum.

RESULTS

At 10 weeks after pregnancy, 25.7% of mothers who initiated breastfeeding no longer breastfed. After controlling for confounders, quitters (mothers who quit smoking during pregnancy and maintained quit status after pregnancy) and postpartum relapsers (mothers who quit smoking during pregnancy and resumed smoking after delivery) did not have significantly higher risk for early weaning than nonsmokers. However, persistent smokers (mothers who smoked before, during, and after pregnancy) were 2.18 times more likely not to breastfeed at 10 weeks (95% confidence interval=1.52, 2.97). Women who smoked 10 or more cigarettes per day postpartum (i.e., heavy postpartum relapsers and heavy persistent smokers) were 2.3-2.4 times more likely to wean their infants before 10 weeks than were nonsmokers.

CONCLUSIONS

Maternal smoking is associated with early weaning. Stopping smoking during pregnancy and decreasing the number of cigarettes smoked postpartum may increase breastfeeding duration.

Why do women stop breastfeeding? Findings from the Pregnancy Risk Assessment and Monitoring System

OBJECTIVE

We examined breastfeeding behaviors, periods of vulnerability for breastfeeding cessation, reasons for breastfeeding cessation, and the association between predelivery intentions and breastfeeding behaviors.

STUDY DESIGN

Using 2 years (2000 and 2001) of data from the Pregnancy Risk Assessment and Monitoring System we assessed the percentage of women who began breastfeeding, continued for < 1 week, continued for 1 to 4 weeks, and continued for > 4 weeks and their reasons for not initiating or stopping. Predelivery breastfeeding intentions of women and their relationship with subsequent breastfeeding behaviors were examined also.

RESULTS

We found that 32% of women did not initiate breastfeeding, 4% started but stopped within the first week, 13% stopped within the first month, and 51% continued for > 4 weeks. Younger women and those with limited socioeconomic resources were more likely to stop breastfeeding within the first month. Reasons for cessation included sore nipples, inadequate milk supply, infant having difficulties, and the perception that the infant was not satiated. Women who intended to breastfeed, thought they might breastfeed, or had ambivalent feelings about breastfeeding were more likely to initiate breastfeeding and to continue through the vulnerable periods of early infancy than were those who did not plan to breastfeed.

CONCLUSIONS

Our findings indicate a need to provide extensive breastfeeding support after delivery, particularly to women who may experience difficulties in breastfeeding.

The changing concept of sudden infant death syndrome: diagnostic coding shifts, controversies regarding the sleeping environment, and new variables to consider in reducing risk

There has been a major decrease in the incidence of sudden infant death syndrome (SIDS) since the American Academy of Pediatrics (AAP) released its recommendation in 1992 that infants be placed down for sleep in a nonprone position. Although the SIDS rate continues to fall, some of the recent decrease of the last several years may be a result of coding shifts to other causes of unexpected infant deaths. Since the AAP published its last statement on SIDS in 2000, several issues have become relevant, including the significant risk of side sleeping position; the AAP no longer recognizes side sleeping as a reasonable alternative to fully supine sleeping. The AAP also stresses the need to avoid redundant soft bedding and soft objects in the infant's sleeping environment, the hazards of adults sleeping with an infant in the same bed, the SIDS risk reduction associated with having infants sleep in the same room as adults and with using pacifiers at the time of sleep, the importance of educating secondary caregivers and neonatology practitioners on the importance of "back to sleep," and strategies to reduce the incidence of positional plagiocephaly associated with supine positioning. This statement reviews the evidence associated with these and other SIDS-related issues and proposes new recommendations for further reducing SIDS risk.

Rates and social patterning of household smoking and breastfeeding in contrasting European settings

OBJECTIVE

To compare rates and social patterning of household smoking and breastfeeding in families with newborn infants in birth cohorts in Coventry, UK and Veria, North Greece.

METHODS

Infants born in 1996 in Coventry, 1999 in Veria were recruited into birth cohort studies using similar methodologies. In Coventry recruitment was by family health visitor at the primary visit; in Veria, hospital-based paediatricians enrolled infants at the neonatal examination. Data were collected at the initial contact on household smoking, type of feeding, and household socio-demographic characteristics. Rates of initial breastfeeding and household smoking with 95% confidence intervals were estimated and breastfeeding and household smoking regressed on parental education and housing tenure in logistic regression models.

RESULTS

Data were available on 2612 Coventry infants and 773 Veria infants. Rates of household smoking and breastfeeding were higher in Veria compared to Coventry. In Coventry, living in rented accommodation and lower maternal and paternal education were associated with household smoking and bottle feeding. Logistic regression models fitted on initiation of breastfeeding failed to show social patterning in Veria but more educated mothers showed a longer duration of breastfeeding. Only low paternal education was associated with household smoking after adjustment for maternal education and housing tenure.

CONCLUSIONS

Smoking and breastfeeding are more prevalent among households with young infants in Veria compared with Coventry. The social patterning of health-related behaviours noted in Coventry is less marked in Veria. The relevance of these findings for public health interventions in the contrasting settings is discussed.

Determinants of breast-feeding and weaning in Alberta, Canada

OBJECTIVE

To assess the determinants of breast-feeding initiation and duration at the population level in Alberta, Canada.

METHODS

Determinants of breast-feeding were assessed based on data from a sample of 1113 women, who represented 150,898 fertile women in Alberta, in the second cycle of the National Population Health Survey conducted 1996-97. Logistic regression analysis was used to estimate the independent effects of various determinants of breast-feeding initiation and duration dichotomized at 4 weeks, 8 weeks, 12 weeks, and 6 months postpartum. All analyses used analytic weights to take both the average design effect and population weights for the complex survey design into account.

RESULTS

The proportion of breast-feeding initiation was 85.6%. It was observed that 71.3% of mothers continued breast-feeding for at least 3 months, and 37.2% of mothers breast-fed their infants for more than 6 months. Determinants of breast-feeding initiation were marital status, education, maternal smoking behaviour, and annual family income. White women and women who were older than 35 years of age were more likely to continue breast-feeding for longer periods, whereas those who smoked during pregnancy were less likely to breast-feed their infants for extended periods. The primary reasons for weaning were breast problems at less than 1 week, insufficient milk production during weeks 1 to 12, and infants who weaned themselves after 3 months.

CONCLUSIONS

Smoking cessation during pregnancy, adequate treatment of early breast problems, and breast-feeding promotion campaigns targeting socioeconomically disadvantaged populations could serve to increase breast-feeding in Canada.

Lutter contre le tabac et promouvoir l'allaitement au Québec : un défi

Quebec's breastfeeding rates are in a deplorable state, and even more so for smoking mothers. Public health providers are trying to increase breastfeeding rates and decrease smoking in this specific target group. Should they prioritise tobacco cessation interventions, or breastfeeding promotion interventions, or give equal priority to both goals at the same time? The authors attempt to scientifically answer this question, through a comprehensive literature review over the last ten years. In general, women who smoke have the tendency be younger, be less educated and more underprivileged than mothers who do not smoke and to breastfeed less often. Smoking mothers who do breastfeed usually wean off breastfeeding earlier than those who do not smoke. Pregnancy is considered an ideal moment to stop smoking, but relapse after giving birth is very high. In light of the range of difficulties faced when trying to quit smoking, health professionals should encourage smoking mothers to breastfeed since the benefits of breastfeeding could actually serve to reduce some of the harmful effects related to tobacco. Nicotine patches can be prescribed to increase the chances for successful tobacco cessation amongst these mothers. To date, few studies have been carried out on nicotine replacement therapies and breastfeeding smokers. More research is needed to evaluate the risks and benefits of nicotine substitutes for this sub-group, in both the short and long term.

Effect of smoking on neonatal and maternal serum and breast milk leptin levels

Maternal smoking is considered to be a risk factor for low birth weight. It is hypothesized that alteration in leptin concentration may be associated with reduced fetal growth. In this study, we assess the effect of smoking during pregnancy on maternal and neonatal serum leptin concentrations, and also on breast milk leptin levels. When the infants were brought to routine physical examination at 7 days old, blood samples and breast milk specimens were taken for leptin measurement from mothers who smoked during pregnancy and their newborns. Nonsmoking mothers and their infants were recruited randomly over the same period as a control group. Maternal age, number of pregnancy, weight of the mothers, birth weight, and gestational age of the infants were similar in both groups (p > 0.05). There was no significant difference between groups in maternal serum and breast milk leptin levels (p = 0.14 and p = 0.96, respectively). However, serum leptin levels were found significantly lower in neonates born to smoking mothers compared with infants born to nonsmoking mothers (p = 0.02). Our findings suggest that maternal smoking dose not have an effect on maternal serum and breast milk leptin levels but decreases neonatal serum leptin concentration independent of birth weight.

Interventions for promoting smoking cessation during pregnancy

BACKGROUND

Smoking remains one of the few potentially preventable factors associated with low birthweight, preterm birth and perinatal death.

OBJECTIVES

To assess the effects of smoking cessation programs implemented during pregnancy on the health of the fetus, infant, mother, and family.

SEARCH STRATEGY

We searched the Cochrane Pregnancy and Childbirth Group trials register and the Cochrane Tobacco Addiction Group trials register (July 2003), MEDLINE (January 2002 to July 2003), EMBASE (January 2002 to July 2003), PsychLIT (January 2002 to July 2003), CINAHL (January 2002 to July 2003), and AUSTHEALTH (January 2002 to 2003). We contacted trial authors to locate additional unpublished data. We handsearched references of identified trials and recent obstetric journals.

SELECTION CRITERIA

Randomised and quasi-randomised trials of smoking cessation programs implemented during pregnancy.

DATA COLLECTION AND ANALYSIS

Four reviewers assessed trial quality and extracted data independently.

MAIN RESULTS

This review included 64 trials. Fifty-one randomised controlled trials (20,931 women) and six cluster-randomised trials (over 7500 women) provided data on smoking cessation and/or perinatal outcomes. Despite substantial variation in the intensity of the intervention and the extent of reminders and reinforcement through pregnancy, there was an increase in the median intensity of both 'usual care' and interventions over time. There was a significant reduction in smoking in the intervention groups of the 48 trials included: (relative risk (RR) 0.94, 95% confidence interval (CI) 0.93 to 0.95), an absolute difference of six in 100 women continuing to smoke. The 36 trials with validated smoking cessation had a similar reduction (RR 0.94, 95% CI 0.92 to 0.95). Smoking cessation interventions reduced low birthweight (RR 0.81, 95% CI 0.70 to 0.94) and preterm birth (RR 0.84, 95% CI 0.72 to 0.98), and there was a 33 g (95% CI 11 g to 55 g) increase in mean birthweight. There were no statistically significant differences in very low birthweight, stillbirths, perinatal or neonatal mortality but these analyses had very limited power. One intervention strategy, rewards plus social support (two trials), resulted in a significantly greater smoking reduction than other strategies (RR 0.77, 95% CI 0.72 to 0.82). Five trials of smoking relapse prevention (over 800 women) showed no statistically significant reduction in relapse.

REVIEWERS' CONCLUSIONS

Smoking cessation programs in pregnancy reduce the proportion of women who continue to smoke, and reduce low birthweight and preterm birth. The pooled trials have inadequate power to detect reductions in perinatal mortality or very low birthweight.

Aboriginal mothers, breastfeeding and smoking

OBJECTIVE

To document the smoking practices of Aboriginal mothers living in Perth during pregnancy and during the subsequent year while feeding their infants.

METHOD

A cohort of mothers was followed from the time of delivery for 12 months to obtain details of infant feeding practices. A total of 455 mothers delivered between May 2000 and July 2001 and 425 completed the baseline questionnaire.

RESULTS

Prior to and during pregnancy, 67% of the mothers smoked regularly. While the rate appeared to decline slightly with the length of breastfeeding, the trend was not significant. The rate of smoking of Aboriginal mothers was significantly greater than for an earlier study of non-Aboriginal mothers in Perth, where the rate was 28.4%. Among Aboriginal women there was no difference in the percentage of smokers and non-smokers who initiated breastfeeding. While fewer women who smoked were still breastfeeding at 24 weeks postpartum, compared with non-smokers (58% vs. 64%), this difference was not significant.

CONCLUSIONS

The percentage of women smoking in this study is consistent with rates reported in the 2001 National Drug Strategy Household Survey. In other studies, smoking is associated with lower rates of breastfeeding initiation and duration, but this was not the case in the Aboriginal mothers.

IMPLICATIONS

Although the high prevalence of smoking identified in this study did not appear to adversely affect breastfeeding, smoking during and after pregnancy does contribute to increased rates of low birth weight and other health problems in early childhood. Targeted antenatal smoking cessation programs are needed for Aboriginal mothers.