Maternal Smoking and Infant Feeding: Breastfeeding is Better and Safer

Academy of Breastfeeding Medicine Clinical Protocol #21: Breastfeeding in the Setting of Substance Use and Substance Use Disorder (Revised 2023)

Background: The Academy of Breastfeeding Medicine (ABM) revised the 2015 version of the substance use disorder (SUD) clinical protocol to review the evidence and provide updated literature-based recommendations related to breastfeeding in the setting of substance use and SUD treatments. Key Information: Decisions around breastfeeding are an important aspect of care during the peripartum period, and there are specific benefits and risks for substance-exposed mother-infant dyads. Recommendations: This protocol provides breastfeeding recommendations in the setting of nonprescribed opioid, stimulant, sedative-hypnotic, alcohol, nicotine, and cannabis use, and SUD treatments. Additionally, we offer guidance on the utility of toxicology testing in breastfeeding recommendations. Individual programs and institutions should establish consistent breastfeeding approaches that mitigate bias, facilitate consistency, and empower mothers with SUD. For specific breastfeeding recommendations, given the complexity of breastfeeding in mothers with SUD, individualized care plans should be created in partnership with the patient and multidisciplinary team with appropriate clinical support and follow-up. In general, breastfeeding is recommended among mothers who stop nonprescribed substance use by the time of delivery, and they should continue to receive ongoing postpartum care, such as lactation support and SUD treatment. Overall, enhancing breastfeeding education regarding substance use in pregnancy and lactation is essential to allow for patient-centered guidance.

Exposure patterns, chemical structural signatures, and health risks of pesticides in breast milk: A multicenter study in China

China is the world's largest pesticide user. These chemicals are bioaccumulative in the human body, and eventually could be transferred from the mother to the fetus/infant via placental and breastfeeding transport, which might pose developmental deficiency risks. In this study, human biomonitoring of legacy pesticides was conducted in three Chinese cities using 60 breast milk samples. The patterns, chemical structural signatures, and the estimated daily intake of pesticides were assessed. The median concentration of HCB (57.8 ng g^-1 lw, Interquartile range: 28.5-76.9 ng g^-1 lw) was the highest among all pesticides, whereas the HCHs, DDXs, TCVP, and heptachlor were also detected. A significantly different pattern of pesticides was found among three sampling cities: the Mianyang cases were mostly DDXs oriented while the Wuhan and Hangzhou cases were under HCB, HCHs, TCVP, and heptachlor influences. Maternal age and pre-pregnancy BMI were found to be the influencing factors for the pesticides in the breast milk, and dietary preferences were an important factor in the exposure scenario. Chemical structural signatures indicated that for HCHs and DDXs the exposure was mostly historical, while the lindane and dicofol exposure may exist among the volunteering mothers. The EF for chiral pesticides did not deviate significantly from the racemic value. The risk from breastfeeding was negligible according to the Chinese and UN standard, while some cases from Hangzhou and Wuhan exceeded the Canadian restrictions. Thus, the adverse health effects of chemical exposure by dietary intake for infants need to be closely monitored in future studies.

Polychlorinated biphenyls (PCBs) in the colostrum samples from the Yangtze River Region: Exposure profile and risk assessment

Polychlorinated biphenyls (PCBs) may transfer into the neonates through the placental transfer and via breastfeeding after the delivery, thus might be harmful to the infant. Sixty colostrum samples in the Yangtze River Region were collected to investigate the concentration, distribution pattern, and enantiomer characteristic of the PCB exposure. Among all samples, over 90% of pollutants were tetra-to hepta-chlorinated PCBs. The sum concentration of the PCB was 512 (IQR: 322-856) ng g^-1 lipid weight. Enantiomer fraction (EF) of PCB 95 and PCB 149 was found lower than the racemic value, while EFs of PCB 45 and PCB 136 were found higher and near-racemic state, respectively. The concentration pattern and enantiomeric properties of the PCBs indicated that the mothers from Mianyang had a recent exposure to PCBs. Among all samples, similar exposure and metabolic pathways of the PCB congeners were observed. PCB exposure showed no significant correlation with the birth outcome of the infants, but 43.3% of the infants have potential health risks via breastfeeding.

Duration of breastmilk feeding of NICU graduates who live with individuals who smoke

BACKGROUND

Breast milk has many benefits for infants, but initiating breastfeeding/pumping can be difficult for mothers of preterm infants, especially those who smoke (or live with individuals who smoke). The primary aim of this study was to identify risks for breastfeeding/pumping cessation with neonatal intensive care unit (NICU) infants' mothers who smoke or live with individuals who smoke, using a novel survival-analytic approach.

METHODS/DESIGN

Mothers (N = 360) were recruited for a secondhand smoke prevention intervention during infants' NICU hospitalizations and followed for ~6 months after infant discharge. Data were obtained from medical records and participant self-report/interviews.

RESULTS

The sample was predominantly ethnic/racial minorities; mean age was 26.8 (SD = 5.9) years. One-fifth never initiated breastfeeding/pumping (n = 67; 18.9%) and mean time-to-breastfeeding cessation was 48.1 days (SD = 57.2; median = 30.4 [interquartile range: 6.0-60.9]). Education, length of stay, employment, race/ethnicity, number of household members who smoke, and readiness-to-protect infants from tobacco smoke were significantly associated with breastfeeding cessation. Further, infants fed breast milk for ≥4 months had 42.7% more well-child visits (p < 0.001) and 50.0% fewer respiratory-related clinic visits (p < 0.05).

CONCLUSIONS

One-quarter of infants admitted to NICUs will be discharged to households where individuals who smoke live; we demonstrated that smoking-related factors were associated with mothers' breastfeeding practices. Infants who received breast milk longer had fewer respiratory-related visits.

IMPACT

One-quarter of NICU infants will be discharged to households where smokers live. Initiating/sustaining breastfeeding can be difficult for mothers of preterm NICU infants, especially mothers who smoke or live with others who smoke. Education, employment, race/ethnicity, length of stay, household member smoking, and readiness-to-protect infants from tobacco smoke were significantly associated with time-to-breastfeeding cessation. Infants fed breast milk for ≥4 months had 42.7% more well-child visits and 50.0% fewer respiratory-related clinic visits, compared to infants fed breast milk <4 months. Data support intervention refinements for mothers from smoking households and making NICU-based healthcare workers aware of risk factors for early breastfeeding cessation.

Sugar-sweetened beverage consumption among Indigenous Australian children aged 0-3 years and association with sociodemographic, life circumstances and health factors

Objective:

To explore beverage intake and associations between sugar-sweetened beverage (SSB) intake and sociodemographic, life circumstances, health and well-being factors in a national cohort of Indigenous children.

Design:

We calculated prevalence ratios for any SSB consumption across exposures, using multilevel Poisson regression (robust variance), adjusted for age group and remoteness. A key informant focus group contextualised these exploratory findings.

Setting:

Diverse settings across Australia.

Participants:

Families of Indigenous children aged 0–3 years, in the Longitudinal Study of Indigenous Children.

Results:

Half (50·7 %, n 473/933) of children had ever consumed SSB at survey, increasing from 29·3 % of 0–12-month-olds to 65·7 % of 18–36-month-olds. SSB consumption prevalence was significantly lower in urban and regional v. remote areas, and in families experiencing socio-economic advantage (area-level advantage, caregiver employed, financial security), better life circumstances (caregiver social support, limited exposure to stressors) and caregiver well-being (non-smoking, social and emotional well-being, physical health). SSB consumption prevalence was significantly lower among those engaged with health services (adequate health-service access, regular prenatal check-ups), except SSB consumption prevalence was higher among those who received home visits from an Aboriginal Health Worker compared with no home visits. Key informants highlighted the role of water quality/safety on SSB consumption.

Conclusions:

A substantial proportion of Indigenous children in this sample consumed SSB from an early age. Health provider information needs to be relevant to the context of families’ lives. Health system strategies must be paired with upstream strategies, such as holistic support programmes for families, reducing racism and improving water quality.

Secondhand Smoke Exposure During Pregnancy and Mothers' Subsequent Breastfeeding Outcomes: A Systematic Review and Meta-Analysis

Secondhand smoke exposure of non-smoking women during pregnancy is associated with a higher risk of adverse birth outcomes. However, the available evidence regarding the association between expectant mothers’ secondhand smoke exposure and breastfeeding outcomes remains limited. This systematic review aimed to examine associations between secondhand smoke exposure of nonsmoking women during pregnancy with the initiation, prevalence, and duration or breastfeeding compared to women who were breastfeeding and had not been exposed to secondhand smoke. Women who smoked during pregnancy were excluded. We included case-control, cross-sectional, and cohort studies with a comparison control group. Medline CINAHL, and EMBASE were searched in January 2017. After screening 2777 records we included eight prospective cohort studies. The risk of bias assessment tool for non-randomized studies indicated a high risk of outcome assessment blinding. Meta-analysis of two studies established that the odds of discontinuation of any brestfeeding before six months were significantly increased in the secondhand smoke exposed women (pooled odds = 1.07 [95%CI = 1.01, 1.14], two studies, 1382 women). Therefore, secondhand smoke might be associated with discontinuing any breastfeeding before six months. More research is necessary to understand the association between secondhand smoke and the initiation, prevalence and duration of breastfeeding.

Exposure to prenatal secondhand smoke and early neurodevelopment: Mothers and Children's Environmental Health (MOCEH) study

BACKGROUND

The association between exposure to secondhand smoke (SHS) during pregnancy and a child's neurodevelopment has not been established yet. We explored the association between prenatal exposure to SHS and neurodevelopment at 24 months of age considering genetic polymorphism and breastfeeding in 720 mothers and their offspring enrolled in the Korean multicenter birth cohort study (Mothers and Children Environmental Health, MOCEH).

METHODS

We quantified urine cotinine concentrations in mothers once from 12th to 20th gestational weeks and excluded those whose urine cotinine levels exceeded 42.7 ng/ml to represent SHS exposure in early pregnancy. Mental developmental index (MDI) and psychomotor developmental index (PDI) values were measured using the Korean version of the Bayley Scales of Infant Development II (K-BSID-II) at 24 months of age. A general linear model was used to assess the relationship between maternal urinary cotinine level and neurodevelopment.

RESULTS

MDI scores were inversely associated with cotinine [β = - 2.73; 95% confidence interval (CI): - 5.32 to - 0.15] in children whose mothers had early pregnancy urinary cotinine levels >1.90 ng/ml. No association was evident in children whose mothers had cotinine levels ≤1.90 ng/ml. This negative association was more pronounced in children whose mothers had both Glutathione S-transferases mu 1 (GSTM1) and theta 1 (GSTT1) null type [β = - 5.78; 95% CI: -10.69 to - 0.87], but not in children whose mothers had any present type of GSTM1/GSTT1 [β = - 1.64; 95% CI: -4.79 to 1.52]. The association was no longer significant when children received breast milk exclusively for up to 6 months [β = - 0.24; 95% CI: -4.69 to 4.20] compared to others [β = - 3.75; 95% CI: -7.51 to 0.00]. No significant association was found for PDI.

CONCLUSIONS

Maternal exposure to SHS during pregnancy may result in delayed MDI in early childhood. This effect might be modified by genetic polymorphism and breastfeeding behavior.

Pharmaceutical strategies for smoking cessation during pregnancy

Introduction: Tobacco use is the most preventable cause of death worldwide, with over 7 million deaths per year. Smoking during pregnancy causes harm to the mother, fetus, and can result in problems for the infant from childhood into adulthood. Practitioners should ask all expectant mothers about tobacco use. For expectant mothers who smoke or recently quit, practitioners should advice to quit and provide psychosocial interventions. Rates of smoking during pregnancy differ between geographical locations, with estimates of 10.8% in the UK and 7.2% in the US. Practitioners should provide expectant mothers unable to quit smoking with information about the risks and benefits of pharmacotherapy and use a patient-centered approach to determine the use. Although there is no definitive evidence on birth outcomes, nicotine replacement therapy and bupropion are adequate pharmacotherapies to help those unable to quit. Areas covered: Herein, this author looks at the various pharmaceutical strategies to help patients cease smoking and provides expert perspectives on the subject. Expert opinion: Additional research on pharmacotherapy is warranted, especially with varenicline. Practitioners working with pregnant patients should be familiar with the evidence for pharmacotherapy in smoking cessation during pregnancy. This evidence can be difficult to navigate due to conflicting results and limitations with the trials.

Prospective associations of breastfeeding and smoking cessation among low-income pregnant women

Although low-income pregnant women have high rates of smoking and low rates of breastfeeding, few studies have examined prospective associations between these risk factors in community samples. Doing so may help improve breast-feeding support programs in this population. We used a secondary analysis of 247 low-income pregnant smokers in Memphis, Tennessee, who were interviewed up to 4 times (twice during pregnancy and twice through 6 months postpartum). Smoking cessation during prepartum and postpartum was defined as a self-report of not smoking for ≥1 week and an expired carbon monoxide level of <10 ppm. Multivariable logistic regression analyses were used to determine whether intent to breastfeed was associated with smoking cessation and whether smoking cessation was associated with actual breastfeeding. Models were adjusted for sociodemographic, pregnancy-related, and smoking-related confounders. Thirty-nine percent of participants intended to breastfeed, and 38% did so. Women who intended to breastfeed were 2 times more likely to quit smoking prepartum (adjusted OR = 1.99, 95% CI [1.06, 3.74]), but not postpartum (adjusted OR = 1.27, 95% CI [0.57, 2.84]). Quitting smoking at baseline and during pregnancy was associated with subsequent breastfeeding (adjusted OR 2.27, 95% CI [1.05, 4.94] and adjusted OR = 2.49, 95% CI [1.21, 5.11]). Low-income women who intended to breastfeed were more likely to quit smoking during pregnancy and those who quit smoking at baseline and prepartum were more likely to breastfeed. Simultaneously supporting breastfeeding and smoking cessation may be very useful to change these important health behaviours among this high-risk population.

Family Physicians' Perceived Prevalence, Safety, and Screening for Cigarettes, Marijuana, and Electronic-Nicotine Delivery Systems (ENDS) Use during Pregnancy

OBJECTIVE

Assess perceptions of prevalence, safety, and screening practices for cigarettes and secondhand smoke exposure (SHSe), marijuana (and synthetic marijuana), electronic nicotine delivery systems (ENDS; eg, e-cigarettes), nicotine-replacement therapy (NRT), and smoking-cessation medications during pregnancy, among primary care physicians (PCPs) providing obstetric care.

METHODS

A web-based, cross-sectional survey was e-mailed to 3750 US physicians (belonging to organizations within the Council of Academic Family Medicine Educational Research Alliance). Several research groups' questions were included in the survey. Only physicians who reported providing "labor and delivery" obstetric care responded to questions related to the study objectives.

RESULTS

A total of 1248 physicians (of 3750) responded (33.3%) and 417 reported providing labor and delivery obstetric care. Obstetric providers (N = 417) reported cigarette (54%), marijuana (49%), and ENDS use (24%) by "Some (6% to 25%)" pregnant women, with 37% endorsing that "Very Few (1% to 5%)" pregnant women used ENDS. Providers most often selected that very few pregnant women used NRT (45%), cessation medications (ie, bupropion or varenicline; 37%), and synthetic marijuana (23%). Significant proportions chose "Do not Know" for synthetic marijuana (58%) and ENDS (27%). Over 90% of the sample perceived that use of or exposure to cigarettes (99%), synthetic marijuana (99%), SHS (97%), marijuana (92%), or ENDS (91%) were unsafe during pregnancy, with the exception of NRT (44%). Providers most consistently screened for cigarette (85%) and marijuana use (63%), followed by SHSe in the home (48%), and ENDS (33%) and synthetic marijuana use (28%). Fewer than a quarter (18%) screened consistently for all substances and SHSe. One third (32%) reported laboratory testing for marijuana and 3% reported laboratory testing for smoking status.

CONCLUSION

This sample of PCPs providing obstetric care within academic settings perceived cigarettes, marijuana, and ENDS use to be prevalent and unsafe during pregnancy. Opportunities for increased screening during pregnancy across these substances were apparent.

Maternal smoking and newborn sex, birth weight and breastfeeding: a population-based study

OBJECTIVE

Today, it is acknowledged that smoking during pregnancy and/or the postnatal period has significant risks for a foetus and newborn child. This research examines the relationship between smoking only postnatally, both during pregnancy and postnatally, and the newborn sex, birth weight and breastfeeding.

METHODS

Total 664 women of randomly selected five primary healthcare centres between the dates 20 February 2010 and 20 July 2010 were included in the research. Statistical analyses were performed with SPSS for Windows 19.0 (Statistical Package for Social Sciences software package). Data were described as mean, standard deviation, percentages and Chi-square tests and backward stepwise logistic regression were analysed.

RESULTS

It was found that the percentage of smoking women with daughters is 2.5 times higher than women with sons. Women who smoke are 3.9 times more likely to start feeding their baby with supplementary infant foods at 4 months or earlier than those who do not smoke. Finally, the risk of a birth weight under 2500 g is 3.8 times higher for maternal smokers.

CONCLUSIONS

This study suggests that women who expect a girl smoke more heavily than those who expect a boy. The birth weight of maternal smokers' newborns is lower. Those women who smoke while breastfeeding start feeding their babies with supplementary infant foods at an earlier age.

Tobacco smoking and breastfeeding: Effect on the lactation process, breast milk composition and infant development. A critical review

Approximately 10% of women report smoking during pregnancy. The number of breastfeeding women who relapse back to smoking is even greater. Smoking may cause adverse changes to the milk's composition by not only reducing its protective properties, but also by affecting the infant's health. The pathophysiological mechanisms underlying these adverse effects are not entirely known. This article is a review of previous reports about the effects of smoking on the lactation process, breast milk composition and infant development. A systematic search for English language articles published until 2015 was made, using a MEDLINE data. The key search terms were "smoking and breastfeeding", "smoking and lactation", "smoking and milk composition", "nicotine and breast milk". Studies have shown that nicotine levels in breast milk of women who smoke are three times higher than those in the plasma levels. Breast milk volume is reduced and the duration of lactation period is shorter. Smoking causes adverse changes to the milk's composition by not only reducing its protective properties, but also affecting infants' response to breastfeeding and to breast milk.

Exposure to Tobacco Metabolites via Breast Milk and Infant Weight Gain: A Population-Based Study

BACKGROUND

Although the immutable benefits of breastfeeding are well documented, information on the potential consequences of exposure to tobacco metabolites specifically via breastfeeding is sparse.

OBJECTIVE

The aim was to conduct the first study of the association between exposure to tobacco metabolites specifically through breastfeeding and infant weight gain.

METHODS

We used historical data from the US Collaborative Perinatal Project. Mothers were classified as nonsmokers, light smokers (1-19 cigarettes/day), and heavy (20+ cigarettes/day) smokers. In-hospital feeding type was observed during a nursery stay after delivery. We conducted stratified analyses among average-for-gestational-age (AGA; N = 23 571) and small-for-gestational-age (SGA; N = 2552) infants. We isolated the effect of exposure to tobacco metabolites specifically through breastfeeding.

RESULTS

Overall, maternal smoking was associated with change in weight-for-length z-score in a dose-response manner. Change in weight z-score was most pronounced among SGA infants of heavy smokers (breastfed: 0.53; 95% confidence interval [CI], 0.12-0.94; formula fed: 0.17; 95% CI, 0.03-0.30). Exposure to tobacco metabolites specifically through breastfeeding was not associated with additional weight gain among AGA infants. Among the much smaller sample of SGA infants, exposure specifically through breastfeeding was associated with marginally significant additional weight gain (0.46; 95% CI, 0.00-0.91) among infants of heavy smokers.

CONCLUSION

Our findings are in accord with recommendations by health agencies for smokers to breastfeed. However, SGA infants exposed to tobacco metabolites via breastfeeding by heavy smokers appear to gain weight more rapidly than other infants. Practical implications of our findings are discussed.

ABM clinical protocol #21: guidelines for breastfeeding and substance use or substance use disorder, revised 2015

A central goal of The Academy of Breastfeeding Medicine is the development of clinical protocols for managing common medical problems that may impact breastfeeding success. These protocols serve only as guidelines for the care of breastfeeding mothers and infants and do not delineate an exclusive course of treatment or serve as standards of medical care. Variations in treatment may be appropriate according to the needs of an individual patient.

The significance of breastfeeding to incarcerated pregnant women: an exploratory study

BACKGROUND

Breastfeeding rates of incarcerated women in the United States are unknown but are likely to be low. Little is known about the breastfeeding views and experiences of incarcerated women. This exploratory study examined the breastfeeding knowledge, beliefs, and experiences of pregnant women incarcerated in New York City jails.

METHODS

Semistructured interviews were conducted with 20 pregnant women in a New York City jail. Research methods were inspired by grounded theory.

RESULTS

Three main themes emerged from women's collective stories about wanting to breastfeed and the challenges that they experienced. First, incarceration removes women from their familiar social and cultural context, which creates uncertainty in their breastfeeding plans. Second, incarceration and the separation from their high-risk lifestyle makes women want a new start in motherhood. Third, being pregnant and planning to breastfeed represent a new start in motherhood and give women the opportunity to redefine their maternal identity and roles.

CONCLUSIONS

Breastfeeding is valued by incarcerated pregnant women and has the potential to contribute to their psychosocial well-being and self-worth as a mother. Understanding the breastfeeding experiences and views of women at high risk for poor pregnancy outcomes and inadequate newborn childcare during periods of incarceration in local jails is important for guiding breastfeeding promotion activities in this transient and vulnerable population. Implications from the findings will be useful to correctional facilities and community providers in planning more definitive studies in similar incarcerated populations. (BIRTH 39:2 June 2012).

Neurodevelopment of Amazonian infants: antenatal and postnatal exposure to methyl- and ethylmercury

Neurodevelopment as Gesell development scores (GDSs) in relation to mercury exposure in infants (<6 months of age) of one urban center and two rural villages, respectively, of fisherman and cassiterite miners. Mean total hair-Hg (HHg) concentrations of infants from Itapuã (3.95 ± 1.8 ppm) were statistically (P = 0.0001) different from those of infants from Porto Velho (3.84 ± 5.5 ppm) and Bom Futuro (1.85 ± 0.9 ppm). Differences in vaccine coverage among these populations resulted in significantly higher (P = 0.0001) mean ethylmercury (EtHg) exposure in urban infants (150 μg) than in infants from either village (41.67 μg, Itapuã; 42.39 μg, Bom Futuro). There was an inverse significant (Spearman r = −0.2300; P = 0.0376) correlation between HHg and GDS for infants from Porto Velho, but not for the rural infants from Bom Futuro (Spearman r = 0.1336; P = 0.0862) and Itapuã (Spearman r = 0.1666; P = 0.5182). Logistic regression applied to variables above or below the median GDS showed that EtHg exposure (estimated probability = −0.0157; P = 0.0070) and breastfeeding score (estimated probability = −0.0066; P = 0.0536) score were significantly associated with GDS. Conclusion. In nurslings whose mothers are exposed to different levels of fish-MeHg (HHg), a higher score of neurological development at six months was negatively associated with exposure to additional TCV-EtHg. Results should be interpreted with caution because of unaccounted variables.

Smoking behaviour before, during, and after pregnancy: the effect of breastfeeding

Data for this study were obtained from a population-based follow-up study in 25 Italian Local Health Units (LHUs) to evaluate pregnancy, delivery, and postpartum care in Italy. A sample of 3534 women was recruited and interviewed within a few days of their giving birth and at 3, 6, and 12 months after delivery, by trained interviewers using questionnaires. The objective of the study was to evaluate changes in smoking behaviour from one interview to the next. Of 2546 women who completed the follow-up, smoking prevalences before and during pregnancy were 21.6% and 6.7%; smoking prevalences and smoking relapse at 3, 6, and 12 months were 8.1% and 18.5%, 10.3% and 30.3%, and 10.9% and 32.3%, respectively. Smoking during and after pregnancy was more likely among women who were less educated, single, not attending antenatal classes, employed, and not breastfeeding. The results show that women who are breastfeeding smoke less than not breastfeeding women, even after controlling for other predictors (i.e.,  smoking relapse at 12 months: OR = 0.43, 95%  CI:  0.19, 0.94). A low maternal mood increases the risk of smoking relapse within 6 months of about 73%. This study also suggests that prolonged breastfeeding reduces the risk of smoking relapse and that this reduction may be persistent in time. Interventions targeting breastfeeding promotion may also indirectly support smoking cessation, even in absence of specific interventions.

Aortic intima-media thickness in nicotine-exposed rat pups during gestation and lactation period

There have been several studies confirming an association between maternal smoking during pregnancy and low birth weight. The detrimental effect of nicotine exposure beginning in fetal life continues during lactation, in infancy and in the early childhood period. In our previous studies, we found increased aortic intima-media thickness (aIMT) as a preatherosclerotic lesion in neonates with intrauterine growth restriction and in infants of smoking mothers. We aimed to evaluate histopathologically the effect of nicotine exposure during pregnancy and lactation period on fetal growth and aIMT at postnatal 45 days of age (end of the mid-adolescent period) in rat pups living in the same conditions. Gravid rats were assigned into three groups. In nicotine A, pregnant rats received 6 mg/kg/day nicotine intraperitoneally during pregnancy from 1 to 21 days of gestation and lactation (until postnatal day 21). Nicotine B received 3 mg/kg/day nicotine for the same period. Control pregnant rats received only saline intraperitoneally. Abdominal aIMT was studied histopathologically at postnatal 45 days of age. Nicotine exposure resulted in decreased birth weight and pregnancy weight gain. The mean aIMT values of the rat pups exposed to nicotine in both nicotine A and B groups were higher than those of the control group (103.78 ± 21.33 μm, 99.11 ± 30.12 μm, and 62.56 ± 7.18 μm, respectively). In conclusion, the detrimental effect on birth weight of nicotine exposure that began in fetal life is dose dependent. Nicotine exposure during intrauterine life and the lactation period causes increased aIMT in rat pups.

Speciation of methyl- and ethyl-mercury in hair of breastfed infants acutely exposed to thimerosal-containing vaccines

BACKGROUND

Different chemical forms of mercury occur naturally in human milk. The most controversial aspect of early post-natal exposure to organic mercury is ethylmercury (EtHg) in thimerosal-containing vaccines (TCV) still being used in many countries. Thus exclusively breastfed infants can be exposed to both, fish derived methylmercury (MeHg) in maternal diets and to EtHg from TCV. The aim of the study is to evaluate a new analytical method for ethyl and methyl mercury in hair samples of breastfed infants who had received the recommended schedule of TCV.

METHODS

The hair of infants (<12 months) that had been exposed to TCV (Hepatitis B and DTaP) was analysed. A method coupling isothermal gas chromatography with cold-vapor atomic fluorescence spectrometry was used for MeHg which can also speciate EtHg in biological matrices.

RESULTS

In 20 samples of infants' hair, all but two samples showed variable amounts of MeHg (10.3 to 668 ng/g), while precise and reliable concentrations of EtHg (3.7 to 65.0 ng/g) were found in 15 of the 20 samples. A statistically significant inverse association (r=-05572; p=0.0384) was found between hair-EtHg concentrations and the time elapsed after the last TCV shot.

CONCLUSIONS

The analytical method proved sensitive enough to quantify EtHg in babies' hair after acute exposure to thimerosal in vaccine shots. Provided that the mass of hair was above 10mg, organic-mercury exposure during early life can be speciated, and quantified in babies' first hair, thus opening opportunities for clinical and forensic studies.

Breastfeeding initiation in a rural sample: predictive factors and the role of smoking

The study objective was to identify demographic, medical, and health behavior factors that predict breastfeeding initiation in a rural population with low breastfeeding rates. Participants were 2323 women who experienced consecutive deliveries at 2 hospitals, with data obtained through detailed chart review. Only half the women initiated breastfeeding, which was significantly associated with higher levels of education, private insurance, nonsmoking and non-drug-using status, and primiparity, after controlling for confounders. Follow-up analyses revealed that smoking status was the strongest predictor of failure to breastfeed, with nonsmokers nearly twice as likely to breastfeed as smokers and with those who had smoked a pack per day or more the least likely to breastfeed. Findings reveal many factors placing women at risk for not breastfeeding and suggest that intervention efforts should encourage a combination of smoking cessation and breastfeeding while emphasizing that breastfeeding is not contraindicated even if the mother continues to smoke.

Smoking cessation in pregnancy

Managing smoking cessation during pregnancy is vital to the wellbeing of the fetus and the mother. Women who continue to smoke during pregnancy expose the fetus to thousands of chemicals which have been shown to cause deleterious short- and long-term effects. Although a large majority of women cease smoking early in the pregnancy, many of them relapse following delivery. Following a review of current research, an overview of the safety and efficacy of smoking cessation treatments for pregnant women will be considered. Limited research has been performed in this field; however, it can be concluded that low-dose intermittent nicotine replacement therapy is a safe treatment modality for women who smoke during pregnancy. At present there has been no research on other current smoking cessation treatments; however, we will suggest techniques to improve cessation rates and strategies to reduce relapse.

Thimerosal exposure (from tetanus-diphtheria vaccine) during pregnancy and neurodevelopment of breastfed infants at 6 months

AIM

We studied the effect on neurodevelopment of infants who are exposed to thimerosal in tetanus-diphtheria (Td) vaccines during pregnancy.

METHODS

We compared Gesell Developmental Schedules (GDS) of exclusive breastfed infants at 6 months born to mothers who received Td (1 to 3 doses) against those who were born to mothers who did not take such vaccines.

RESULTS

Compared with the group of infants not exposed to ethylmercury in utero, the infants of exposed mothers showed no significant difference in neurodevelopment delays. Although there was a significant correlation between hair-Hg of mothers and hair-Hg of neonates (Spearman r = 0.353; p = 0.0011), there was no significant correlation between the level of in utero exposure to ethylmercury in Td vaccines and neonate's hair-Hg concentrations (Spearman r = 0.060; p = 0.5922). However, regression analysis showed that GDS at 6 months was significantly associated with total mercury concentration of neonate's hair but was not sensitive to the number of vaccines taken by the mother.

CONCLUSION

Early neurodevelopment of exclusively breastfed infants is sensitive to in utero exposure to mercury, but maternal thimerosal exposure in tetanus-diphtheria vaccines per se cannot portend clinical neurodevelopment delays measured by GDS at 6 months.

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.

Breastfeeding is an essential complement to vaccination

AIM

This article explores the role of breastfeeding in different aspects of vaccination in the first 6 months when infants are still developing: (1) pain management; (2) immunomodulation of infants' vaccine responses; (3) metabolism of thimerosal.

METHODS

Major databases were searched for studies that addressed outcomes of related issues.

RESULTS

Studies reveal that breastfeeding can: (1) help mothers and infants to cope with the stressful situations that accompany parenteral vaccines; (2) improve response to vaccines in the still maturing immunologic and enterohepatic systems of infants; (3) influence physiologic parameters that can change metabolism of ethylmercury derived from some vaccines.

CONCLUSION

Health promotion that supports vaccinations should also emphasize early initiation and maintenance of exclusive breastfeeding up until 6 months for maximum protection of the infants with a possible beneficial effect on the vaccine response. Paediatric professionals should inform mothers of the proven benefits of breastfeeding and its importance in complementing vaccination and lowering stress and the risk of untoward reactions on susceptible infants.

Effect of passive smoking on growth and infection rates of breast-fed and non-breast-fed infants

BACKGROUND

The aim of the present study was to determine the effect of passive tobacco smoking on growth and infection rate of infants, and to evaluate whether breast-feeding might be protective against harmful effects of cigarette smoke.

METHODS

A cross-sectional study on 254 6-7-month-old infants was carried out. A questionnaire was given to mothers; and infants' head circumference, bodyweight, height, and urinary cotinine levels were measured.

RESULTS

Multivariate analysis of factors influencing lower respiratory tract infections showed that smoking mothers increased the rate by 9.1-fold; breast-feeding decreased it by 3.3-fold; formula feeding at birth increased it by a factor of 15.2; another smoker at home increased it by a factor of 40.1. Multivariate analysis of factors influencing upper respiratory tract infections showed that smoking mothers increased the rate by a factor of 23; early formula feeding increased it by a factor of 62; breast-feeding decreased it by a factor of 5; smoking fathers increased it by a factor of 15. Multivariate analysis of factors influencing otitis media found that smoking mothers and fathers increased it by a factor of 9.4 and 6.15, respectively, and breast-feeding decreased it by a factor of 5.4.

CONCLUSION

Tobacco smoke exposure of infants has negative consequences on growth, otitis media, and upper and lower respiratory tract infections. Breast-feeding promoted the growth of infants who were passively exposed to tobacco smoke and protected them against infections. Smoking should not be permitted in households with infants. When this is impossible, breast-feeding should be promoted to protect the infants against the health hazards of passive smoking.

Are starting and continuing breastfeeding related to educational background? The generation R study

OBJECTIVE

To assess the effect of a woman's educational level on starting and continuing breastfeeding and to assess the role of sociodemographic, lifestyle-related, psychosocial, and birth characteristics in this association.

METHODS

We used the data of 2914 participants in a population-based prospective cohort study. Information on educational level, breastfeeding, sociodemographic (maternal age, single parenthood, parity, job status), lifestyle-related (BMI, smoking, alcohol use), psychosocial (whether the pregnancy was planned, stress), and birth (gestational age, birth weight, cesarean delivery, place and type of delivery) characteristics were obtained between pregnancy and 12 months postpartum. Odds ratios and 95% confidence intervals of starting and continuing breastfeeding for educational level were obtained by logistic regression, adjusted for each group of covariates and for all covariates simultaneously.

RESULTS

Of 1031 highest-educated mothers, 985 (95.5%) started breastfeeding; the percentage was 73.1% (255 of 349) in the lowest-educated mothers. At 6 months, 39.3% (405 of 1031) of highest-educated mothers and 15.2% (53 of 349) of lowest-educated mothers were still breastfeeding. Educationally related differences were present in starting breastfeeding and the continuation of breastfeeding until 2 months but not in breastfeeding continuation between 2 and 6 months. Lifestyle-related and birth characteristics attenuated the association between educational level and breastfeeding, but the association was hardly affected by sociodemographic and psychosocial characteristics.

CONCLUSIONS

Decisions to breastfeed were underlain by differences in educational background. The underlying pathways require further research. For the time being, interventions on promoting breastfeeding should start early in pregnancy and should increase their focus on low-educated women.

Alternative regression models to assess increase in childhood BMI

BACKGROUND

Body mass index (BMI) data usually have skewed distributions, for which common statistical modeling approaches such as simple linear or logistic regression have limitations.

METHODS

Different regression approaches to predict childhood BMI by goodness-of-fit measures and means of interpretation were compared including generalized linear models (GLMs), quantile regression and Generalized Additive Models for Location, Scale and Shape (GAMLSS). We analyzed data of 4967 children participating in the school entry health examination in Bavaria, Germany, from 2001 to 2002. TV watching, meal frequency, breastfeeding, smoking in pregnancy, maternal obesity, parental social class and weight gain in the first 2 years of life were considered as risk factors for obesity.

RESULTS

GAMLSS showed a much better fit regarding the estimation of risk factors effects on transformed and untransformed BMI data than common GLMs with respect to the generalized Akaike information criterion. In comparison with GAMLSS, quantile regression allowed for additional interpretation of prespecified distribution quantiles, such as quantiles referring to overweight or obesity. The variables TV watching, maternal BMI and weight gain in the first 2 years were directly, and meal frequency was inversely significantly associated with body composition in any model type examined. In contrast, smoking in pregnancy was not directly, and breastfeeding and parental social class were not inversely significantly associated with body composition in GLM models, but in GAMLSS and partly in quantile regression models. Risk factor specific BMI percentile curves could be estimated from GAMLSS and quantile regression models.

CONCLUSION

GAMLSS and quantile regression seem to be more appropriate than common GLMs for risk factor modeling of BMI data.

Persistent, bioaccumulative and toxic substances in fish: human health considerations

Fish are important dietary items that provide essential nutrients. Fish however, bioaccumulate monomethyl mercury (MMHg) and organo-halogenated pollutants (OHP) that are persistent bioaccumulative and toxic substances (PBTS). Unlike man-made OHP, MMHg is mainly of natural origin but background concentrations of aquatic systems are determined by the environmental Hg-methylating potential. Industrial activities can modulate environmental discharges and fish bioaccumulation of PBTS. Fish and seafood consumption are associated with human body load of PBTS, but farming practices that utilize fishmeal increase the terrestrial food chain resulting in farm-animal accumulation of PBTS. These substances are neurotoxic and endocrine active that can impact humans and wild life, but chemical characteristics of MMHg and OHP modulate interactions with animal tissues. MMHg is protein reactive with a faster metabolism (months) than OHP that are stored and slowly (years) metabolized in fat tissues. Except for brain-Hg, neither Hg nor OHP in tissues are markers of toxic effects; however, deficits in neurobehavioral test-scores of children have been shown in some fish-eating populations. These deficits are transient and within normal range, and are not prodromes of neurological diseases. Although population studies show that consumption of fish at current levels of contamination do not explain neurological disorders, endocrine activity remains controversial. Understanding risk of hazard caused by fish-PBTS consumption requires a wide range of expertise. We discuss chemical, toxic, metabolic, and ecological characteristics associated with PBTS in fish. There are proven health outcome derived from fish consumption, while risk of exposure to avoidable PBTS is a chance that can be minimized by societal actions.

Infantile colic, maternal smoking and infant feeding at 5 weeks of age

Background: Many parents seek help from health professionals because of their infants' persistent crying in the early months. The aetiology of this condition, often labelled ``infantile colic'', is still unclear. Aims: To assess whether smoking during pregnancy, and/or smoking at infant age 5 weeks, is associated with infantile colic, and to describe how feeding at infant age 5 weeks and smoking are related to colic. Methods: This was a community-based study, with telephone interviews in late pregnancy, and at infant age 5 weeks, covering 1,625 mother—infant dyads, i.e. 86% of the eligible population. Results: Daily maternal smoking in pregnancy was related to subsequent colic, with an age-adjusted odds ratio (OR) of 1.74 (95% confidence interval 1.08—2.82). In the multivariate model, the OR was largely unaltered. The association between smoking at infant age 5 weeks and colic did not reach statistical significance. The subgroups based on smoking and infant feeding were small, but the results suggest that exclusive breast-feeding was protective against colic, including for infants of smoking mothers. Conclusions: This study presents yet another argument why smoking in pregnancy should be discouraged — some cases of infantile colic may be avoided. With regard to mothers who are not able to give up smoking, the results add some support for the conclusion that if a mother is worried about colic, she certainly should not refrain from breast-feeding even if she smokes.