The relationship between breast-feeding and infant health and development

Mercury exposure assessment in Iranian pregnant women's hair with respect to diet, amalgam filling, and lactation

Our aim for carrying out this study was to estimate the levels of mercury in the hair of pregnant women and its association with fish consumption and amalgam fillings. From November 2007 to January 2008, 100 hair samples were collected randomly from three groups of pregnant women: Ahvaz in the south of Iran, Noushahr in the north, and the countryside of Noushahr. Significant differences were found in these three groups of pregnant women's samples (p>0.05). The mean mercury level in women's hair was found to be 0.37 μg/g (range, 0.11-3.57 μg/g). Only in 2 % of collected hair samples did the total mercury (THg) level exceed the United States Environmental Protection Agency-recommended 1.0 μg/g. In addition, there was a positive correlation of THg content in Ahvaz group's samples with respect to fish consumption (r=0.41, p=0.02) and a negative correlation of THg content in those who consumed vegetables and fruit. The level of education also played an indicating factor in this group. Moreover, significant association was found between the residence time and Hg concentration of women's hair samples collected from Noushahr (p>0.05). Similarly, the same correlations were found between hair mercury levels and the time since the first filling, number of dental fillings, pregnancy interval, and lactating period.

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.

Organochlorine pesticide and polychlorinated biphenyl residues in human milk from the Southern Coast of Caspian Sea, Iran

In the present study, human milk was sampled in October 2006 from Nour and Noushahr cities and their countryside on the Southern Coast of Caspian Sea, Iran. They were analyzed for organochlorine pesticides, such as dichlorodiphenyltrichloroethane (DDT) and its metabolites, hexachlorobenzene (HCB), alpha, beta and gamma-hexachlorocycloexane (HCH) isomers and six PCBs congeners (IUPAC Nos. 28, 52, 101, 138, 153 and 180). Average concentrations of HCHs, DDTs, PCBs and HCB were 3780, 2554, 1560 and 930 ng g(-1) lipid wt, respectively. There was no significant difference between the concentrations of investigated pollutants between the two cities and their countryside. No significant differences in OCPs and PCBs were found between primiparous and multiparous mothers. There was no correlation between levels of OCPs and PCBs in human milk and the age of mothers. There was a significant difference in the organochlorine levels, including DDTs, between mothers who have eaten fish once a week and those who consumed fish more than once (p>0.05). An analysis of the infant exposure to OCPs and PCBs via breast milk indicated that the daily intake rates for most of the mothers were above the guideline proposed by Health Canada which is definitely caused on children health for concern.

Infant feeding patterns in the Finnish type I diabetes prediction and prevention nutrition study cohort

OBJECTIVE

To investigate infant feeding patterns during the first 2 y and their relation to sociodemographic factors.

DESIGN

A population-based cohort study.

SETTING

Oulu and Tampere University Hospital district areas 1996-1999, Finland.

SUBJECTS AND METHODS

All newborn infants (n=675) with increased genetic risk for type I diabetes were invited to the study in 1996-1997. Of these, 429 (64%) completed the dietary follow-up form by the time they reached 2 y of age.

RESULTS

The median duration of exclusive breastfeeding (BF) was 1.8 months (range 0-6 months) and that of total BF 7.0 months (0.3-25 months). Among the infants 20% were exclusively breastfed at least 4 months (recommendation 4-6 months). Infants were introduced to infant formula at the median age of 1.8 months (range 0-25 months) and other supplementary foods at the median age of 3.5 months (1-6 months). Infant's ponderal index at birth was inversely associated with the duration of total BF. The age of introduction of supplementary foods correlated positively with the duration of total BF. Longer parental education and increased maternal age were associated with a longer duration of BF and older age at introduction of supplementary foods. Infant formula and other supplementary foods were added earlier to the diet of the boys than that of the girls.

CONCLUSION

Duration of breastfeeding in Finland is shorter than recommended. Compliance with the current recommendations on the timing of introduction of first supplementary food and dairy products is relatively poor. The diet during infancy seems to be conspicuously influenced by the duration of parental education, maternal age and the sex of the infant.

Levels of organohalogenated persistent pollutants in human milk from Kahramanmaraş region, Turkey

The levels of 1,1,1-trichloro-bis-2,2'-(4-chlorophenyl) ethane (p,p'-DDT) and its metabolites, hexachlorobenzene (HCB), hexachlorocyclohexane isomers (HCHs), chlordanes (trans- and cis-chlordane, oxychlordane and trans-nonachlor), 11 polychlorinated biphenyl (PCB) congeners, and 7 polybrominated diphenyl ether (PBDE) congeners were measured in 37 individual human milk samples from Kahramanmaraş region, Turkey. Organochlorine pesticides were the major contaminants in the milk samples. p,p'-DDE and p,p'-DDT were detected in all samples, while beta-HCH had a detection frequency of 97%. The sum of the DDTs in human milk samples varied between 0.52 and 315.8 ng/g wet weight (ww) with a mean ratio between p,p'-DDE and p,p'-DDT equal to 31.1. p,p'-DDD could be measured only in six samples. beta-HCH was the most prevalent HCH isomer with a mean value of 2.08 ng/g ww. The mean concentration of gamma-HCH was 0.38 ng/g ww, while alpha-HCH was not detected in any sample. HCB is found in 95% of the milk samples with a mean concentration of 0.30 ng/g ww. The mean value for the sum of chlordanes was 0.39 ng/g ww, with oxychlordane and trans-nonachlor being the principal contributors. PCBs could be measured only in 8 out of 37 samples and their concentration ranged between <0.15 and 1.92 ng/g ww for the sum of PCBs. PCB profiles were dominated by congeners 153, 180 and 138. PBDEs were detected only in 3 out of 37 samples, with the highest value being 0.014 ng/g ww (0.40 ng/g lipid weight) and BDE 47 was the dominant congener. Although the number of samples is relatively low and they are not representative for the whole Turkish population, the results of the present study are important to provide additional data on the concentrations of persistent organochlorinated pollutants in Turkey and show as first the PBDE levels in Turkish population.

Varicella, ephemeral breastfeeding and eczema as risk factors for multiple sclerosis in Mexicans

OBJECTIVE

It has been suggested that the incidence of multiple sclerosis (MS) in Mexico and other countries of Latin America has increased steadily for the last two decades. We made a thorough search of antecedents on MS patients that could be potential risk factors.

METHODS

A case-control study was conducted using a questionnaire that included demographic, nutritional, infectious and personal antecedents previously identified in other reports as possible risk factors for MS.

RESULTS

The frequency of varicella, ephemeral breastfeeding and eczema in the medical history of MS patients were significant when compared with controls; all appeared to be mutually additive. However, they were unrelated with clinical characteristics or disease severity.

CONCLUSION

During the last decades, breastfeeding has been abandoned in large segments of society and the incidence of varicella and childhood eczema keeps a north-south gradient similar to that described for MS. These factors may participate in the sharp increase of MS in countries like Mexico traditionally considered as an area of very low incidence.

A pilot study to assess the viability of a randomised controlled trial of methods of supplementary feeding of breast-fed pre-term babies

OBJECTIVES

to compare the impact of two methods of supplementary feeding of pre-term babies (bottle vs cup) on subsequent breast feeding and to assess the feasibility of using a randomised controlled trial (RCT) to investigate the topic.

DESIGN AND METHOD

small scale prospective RCT. Data on breast feeding, as defined as the exclusive method of feeding, were collected. A range of relevant bio-data was also collected and their impact on breast feeding assessed.

SETTING

a special care baby unit in a District General Hospital in the UK.

PARTICIPANTS

over a three-month period, all pre-term babies (32-37 weeks' gestation) who fulfilled the inclusion criteria and has been born to mothers who had expressed a pre-partum desire to breast feed, who had consented to take part, were included (n=14).

PROCEDURE

the eligible babies were randomly allocated to supplementary feeding of breast milk, via either a cup or a bottle. Whether or not the baby was being breast fed at discharge was noted.

FINDINGS

the study suggested that this RCT framework is a viable method of investigating baby feeding. Because of the small-scale nature of the project, the actual database must be treated with extreme caution. No significant differences were found between the two groups in terms of breast feeding. However, the mothers reported high levels of support and also the breast-feeding rates were above the national averages. These two findings could have contributed to the non-significant results observed in this analysis.

CONCLUSIONS

if the present findings could be supported by further research, then the non-significant results relating method of supplementary feeds to subsequent breast feeding could be explained by reference to three factors. Firstly, there is, in fact, no real effect of method of supplementary feeding and subsequent breast feeding; secondly, the method adopted differed from existing research and thus may be expected to produce non-corroborative results; and finally, the overall levels of breast feeding within the Unit generally were higher than the national average. The relevance of the RCT for investigating this subject is also discussed with reference to the present data set. Further experimental work to develop these ideas and to identify causal links is required.

Concentrations of organochlorine pesticides in milk of Nicaraguan mothers

Breast-milk samples from 101 mothers from the basin of Rio Aloya, Nicaragua, were collected on two occasions within the first trimester of lactation. Milk samples were analyzed for 13 organochlorine pesticides: (1) p,p'-dichlorophenyldichloroethylene; (2) p,p'-dichlorophenyltrichloroethane; (3) p,p'-dichlorophenyldichlorodiene; (4) alpha-hexachlorocyclohexane; (5) beta-hexachlorocyclohexane; (6) gamma-hexachlorocyclohexane; (7) delta-hexachlorocyclohexane; (8) toxaphene; (9) dieldrin; (10) endrin; (11) aldrin; (12) heptachlor; and (13) heptachlor-epoxide. Organochlorines of the dichlorodiphenylethane class (i.e., p,p'-dichlorodiphenylethane and p,p'-dichlorodiphenylethane) were found in all samples and at the highest mean concentrations observed in the study. Chemicals in the hexachlorocyclohexane family (i.e., alpha- and delta-hexachlocyclohexane) were not found at all (0%), and the other hexachlorocyclohexane compounds (i.e., beta > gamma) were found in less than 6% of the samples. Twenty percent or less of the sample contained chlorInated cyclodienes (i.e., dieldrin > endrin > heptachlor-epoxide > heptachlor). No measurable concentrations of alpha-hexachlorocyclohexane, aldrin, p,p'-dichlorophenyldichlorodiene, and toxaphene were found in the breast milk samples. Analysis of variance demonstrated that only the concentration of p,p'-dichlorophenyldichloroethylene p,p'-dichlorophenyltrichloroethane, and endrin were affected significantly by maternal age. Overall, with the exception of p,p'-chlorophenyldichloroethylene, and p,p'-dichlorophenyltrichloroethane, the mean concentrations of the analyzed pesticides were low. Total p,p'-dichlorophenyltrichloroethane concentrations that exceeded the allowed daily intake set by the World Health Organisation were found in 5.9% of the samples.

Secular trends in breastfeeding and parental smoking

To explore the association between smoking and breastfeeding, we obtained data from a retrospective questionnaire-based national survey comprising a random sample (n = 34799) of all mothers giving birth in Norway 1970-91. Variables studied were postpartum smoking habits for both parents, duration of breastfeeding, infant's year of birth and parental age. The response rate was 70% (n = 24438). During the study period, the maternal postpartum smoking prevalence decreased from 38% to 26%. The proportion breastfeeding at 6 months increased from 15% to 44% among smokers, and from 30% to 72% among non-smokers. In spite of a considerable increase in breastfeeding both among smokers and non-smokers, the proportion of breastfeeding, non-smoking women at 6 months was twice that of smoking women during the whole period. Furthermore, the duration of breastfeeding was shorter among young mothers and when the fathers were smoking. There was epidemiological evidence that the effect on breastfeeding of smoking might represent both biological and social mechanisms.

Milk fat globule glycoproteins in human milk and in gastric aspirates of mother's milk-fed preterm infants

Human milk fat globule (HMFG) glycoproteins can prevent infections by microorganisms in breast-fed infants; the MUC-1 mucin inhibits binding of S-fimbriated Escherichia coli to buccal mucosa, and lactadherin may prevent symptomatic rotavirus infections. In this study, the survival of these HMFG glycoproteins in the stomach of human milk-fed preterm infants (gestational age = 27.5 +/- 0.4 wk) was assessed, and levels in their mothers' milk determined, using specific RIAs. Butyrophilin, a major component of HMFG membrane that has no demonstrated antimicrobial activity, was studied for comparison. The levels of mucin, lactadherin, and butyrophilin in 41 milk samples of 20 mothers were 729 +/- 75, 93 +/- 10, and 41 +/- 3 microg/mL, respectively. Mucin and lactadherin were significantly higher in early milk samples (<15 d postpartum) than in later milk samples (15-90 d postpartum), whereas butyrophilin showed no such difference. Significant amounts of mucin and lactadherin were found in almost all gastric aspirates of human milk-fed infants, even 4 h after feeding (mucin, 270 +/- 30 microg/mL; lactadherin, 23.2 +/- 4.4 microg/mL), whereas butyrophilin was rapidly degraded in the majority of aspirates. Western blot analysis demonstrated that the immunoreactive mucin, lactadherin, and butyrophilin in the milk-fed gastric aspirates had the expected native molecular weights. Mucin and lactadherin survived at all gastric pH values, whereas butyrophilin was found only at pH > 4. Neither lactadherin nor butyrophilin were detected in gastric aspirates of formula-fed infants (gestational age = 27.8 +/- 0.5 wk), whereas the very low level of mucin (9.1 +/- 1.1 microg/mL) in this group is presumably cross-reacting gastric mucin. These results demonstrate that two HMFG glycoproteins implicated in prevention of infection, MUC-1 mucin and lactadherin, survive and maintain their integrity in the stomachs of human milk-fed preterm infants.

Breastfeeding and later cognitive and academic outcomes

OBJECTIVE

This study examines the associations between duration of breastfeeding and childhood cognitive ability and academic achievement over the period from 8 to 18 years using data collected during the course of an 18-year longitudinal study of a birth cohort of >1000 New Zealand children.

METHOD

During the period from birth to age 1 year, information was collected on maternal breastfeeding practices. Over the period from 8 to 18 years, sample members were assessed on a range of measures of cognitive and academic outcomes including measures of child intelligence quotient; teacher ratings of school performance; standardized tests of reading comprehension, mathematics, and scholastic ability; pass rates in school leaving examinations; and leaving school without qualifications.

RESULTS

Increasing duration of breastfeeding was associated with consistent and statistically significant increases in 1) intelligence quotient assessed at ages 8 and 9 years; 2) reading comprehension, mathematical ability, and scholastic ability assessed during the period from 10 to 13 years; 3) teacher ratings of reading and mathematics assessed at 8 and 12 years; and 4) higher levels of attainment in school leaving examinations. Children who were breastfed for >/=8 months had mean test scores that were between 0. 35 and 0.59 SD units higher than children who were bottle-fed. Mothers who elected to breastfeed tended to be older; better educated; from upper socioeconomic status families; were in a two-parent family; did not smoke during pregnancy; and experienced above average income and living standards. Additionally, rates of breastfeeding increased with increasing birth weight, and first-born children were more likely to be breastfed. Regression adjustment for maternal and other factors associated with breastfeeding reduced the associations between breastfeeding and cognitive or educational outcomes. Nonetheless, in 10 of the 12 models, fitted duration of breastfeeding remained a significant predictor of later cognitive or educational outcomes. After adjustment for confounding factors, children who were breastfed for >/=8 months had mean test scores that were between 0.11 and 0.30 SD units higher than those not breastfed.

CONCLUSIONS

It is concluded that breastfeeding is associated with small but detectable increases in child cognitive ability and educational achievement. These effects are 1) pervasive, being reflected in a range of measures including standardized tests, teacher ratings, and academic outcomes in high school; and 2) relatively long-lived, extending throughout childhood into young adulthood.