Smoking status of breastfeeding women

Factors affecting breastfeeding duration in Greece: What is important?

AIM: To investigate factors associated with breastfeeding duration (BD) in a sample of mothers living in Greece.

METHODS: Four hundred and twenty-eight mothers (438 infants) were initially recruited in a tertiary University Hospital. Monthly telephone interviews (1665 in total) using a structured questionnaire (one for each infant) were conducted until the sixth postpartum month. Cox regression analysis was used to assess factors influencing any BD.

RESULTS: Any breastfeeding rates in the first, third, and sixth month of the infant’s life reached 87.5%, 57.0% and 38.75%, respectively. In the multivariate analysis, maternal smoking in the lactation period [hazard-ratio (HR) = 4.20] and psychological status (HR = 1.72), and the introduction of a pacifier (HR = 2.08), were inversely associated, while higher maternal education (HR_{university/collegevsprimary/high school} = 0.53, HR_{master’svsprimary/high school} = 0.20), and being an immigrant (HR = 0.35) were positively associated with BD.

CONCLUSION: Public health interventions should focus on campaigns against smoking during lactation, target women of lower educational status, and endorse the delayed introduction of pacifiers.

Predictive Models for Characterizing Disparities in Exclusive Breastfeeding Performance in a Multi-ethnic Population in the US

OBJECTIVES

Maternal lactation performance varies across populations, yet the relative impact of maternal sociodemographics, perinatal factors, and birth outcomes on disparities in exclusive breastfeeding (XBR) outcomes is not well known. We aimed to develop predictive models and compare the relative contribution of predictors for XBR initiation and XBR ≥ 6 months.

METHODS

Infant feeding data were obtained from women with children aged 0-6 years (n = 1471) in a multi-ethnic cross-sectional study in the US (2011-2012). We compared discriminant ability of predictors for ever XBR and XBR ≥ 6 months using discriminant function analysis, respectively. We also calculated adjusted ORs for factors associated with XBR outcomes and breast-bottle feeding (BrBot) subgroups.

RESULTS

Maternal sociodemographics (education level, marital status, nativity, and age at childbirth) had greater discriminating abilities in predicting ever XBR and XBR ≥ 6 months than birth outcomes and perinatal factors. Foreign-born women were two-fold more likely to initiate XBR but not necessarily continue to 6 months compared to their US-born counterparts. Factors associated with BrBot subgroups differed from those associated with XBR outcomes, whereas maternal age was the only predictor consistently associated with ever XBR, XBR ≥ 6 months, and BrBot subgroups. The areas under the receiver operating characteristic curves for models predicting ever XBR and XBR ≥ 6 months were 0.88 (95 % CI 0.85, 0.91) and 0.90 (95 % CI 0.88, 0.93), respectively.

CONCLUSIONS

Findings underscore the importance of educational, clinical, and social support to promote XBR in mothers with sociodemographic factors predictive of none or poor XBR outcomes.

Association of maternal smoking status with breastfeeding practices: Missouri, 2005

OBJECTIVE

We sought to determine the association of smoking status as a risk factor for reduced initiation and duration of breastfeeding.

METHODS

The Missouri Pregnancy Related Assessment and Monitoring System collected a stratified sample of new mothers in 2005. Surveys were mailed, with telephone follow-up, and completed within 2 to 12 months after delivery. Respondents were classified as nonsmokers, smokers who quit during pregnancy, light smokers (<or=10 cigarettes per day), or moderate/heavy smokers (>10 cigarettes per day). Multivariable binomial regression and Cox proportional hazards models were used to assess breastfeeding initiation and duration according to smoking status.

RESULTS

Overall, 1789 women participated (weighted response rate: 61%). Approximately 74% of the women ever breastfed; 31% of the women ever smoked while pregnant. Compared with nonsmokers, the moderate/heavy smokers and light smokers were less likely to initiate breastfeeding, after controlling for sociodemographic characteristics, the presence of other smokers in the household, alcohol use, mode of delivery, and infant hospitalization. Compared with nonsmokers, the moderate/heavy smokers, light smokers, and smokers who quit during pregnancy were more likely to wean over time, controlling for the same covariates. There were no significant differences between nonsmokers and smokers regarding reasons for not initiating or ceasing breastfeeding.

CONCLUSIONS

Mothers who smoked initiated breastfeeding less often and weaned earlier than nonsmoking mothers. Incorporating knowledge of the association between smoking and breastfeeding into existing smoking-cessation and breastfeeding programs could provide opportunities to reduce perinatal exposure to tobacco smoke, improve interest in breastfeeding, and address other barriers to breastfeeding that smoking mothers may face.

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.

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.

Maternal education and the incidence and duration of breast feeding: a prospective study

INTRODUCTION

Duration of breast feeding and factors possibly affecting duration were studied in a population of 2174 newborn infants, with gestational age of >37 weeks, who were born in the Department of Obstetrics and Gynaecology at the University of Florence Hospital between November 15, 1997, and November 14, 1998.

PATIENTS AND METHODS

Nine hundred mothers agreed to participate in the study. Five questionnaires were completed at the end of the 1st, 3rd, 6th, 9th, and 12th postpartum month. These dealt with infant feeding practices, including breast feeding during the previous week. Breast feeding duration was defined as short (1 month); medium-short (>1 month-<3 months); medium (>3-<6 months); medium-long (>6-<9 months), and long (>9 months).

RESULTS

The authors found that 76.3%, 64.7%, 42.3%, 26.4%, and 17% of mothers were still breast feeding at 1, 3, 6, 9, and 12 months after delivery, respectively. The multivariate analysis of the correspondence shows that lack of breast feeding is associated with a birth weight of less than 3000 g, a low level of maternal education, and maternal profession as a housewife or blue collar worker in the commercial sector. A period of breast feeding defined as short or medium-short is associated with mothers who smoke, primiparous mothers, and absence of maternal allergy. The survival curves highlight how the single factor of smoking is an element that leads to a significant difference in the duration of breast feeding. The multiple Cox regression analysis shows a significant negative influence associated with birth weight of less than 3000 g, maternal smoking, and first parity. Above all, among low-birth-weight infants of mothers who smoke, there is a strong correlation with a shorter duration of breast feeding.

DISCUSSION

There is still a need for programs that support and encourage breast feeding, focusing particularly on mothers with a low level of education who give birth to a low-weight infant, primiparous mothers, and smokers.

Maternal smoking and reduced duration of breastfeeding: a review of possible mechanisms

AIM

To systematically review the possible mechanisms by which maternal smoking affects lactation.

METHODS

Databases (Medline, CINAHL, Current Contents, Psychinfo, Sociological Abstracts and the Cochrane Library) were searched for smoking and breastfeeding or infant feeding. The Journal of Human Lactation and Birth were hand-searched, searches were also conducted at NMAA's Lactation Resource Centre and references cited were located where appropriate. Articles were divided into the various ways that smoking could affect breastfeeding and were tabulated.

RESULTS

Most studies were conducted on small samples of animals or humans; the majority were prior to 1985. Most animal studies exposed the animals to much greater levels of nicotine than those to which humans are exposed. Most studies did not examine if breastfeeding behaviour was similar in smokers and non-smokers, and did not consider that any physiological difference found could be the result of poor lactation practices, rather than the cause of poor lactation in smokers. The definition of breastfeeding infants was also problematic in many studies. The effect of smoking on oxytocin in women was only examined in one study, and no effect was found, yet a negative effect of smoking on oxytocin release is reported in the breastfeeding literature.

CONCLUSION

Although there is consistent evidence that women who smoke breastfeed their infants for a shorter duration than non-smokers, the evidence for a physiological mechanism is not strong.