Regression analysis of "current status" life tables on duration of breastfeeding in Sri Lanka

Provided that women report the dates of their children's births with reasonable accuracy, it is possible to derive good estimates of the duration of breastfeeding from women's breastfeeding status at the time of the interview. This paper illustrates the application of conventional regression techniques to the analysis of breastfeeding rates derived in this manner. Construction of current status rates is explained and a comparison between open interval, closed interval, and current status breastfeeding life tables is presented, indicating the extent of bias to which tables of the former types are open. Birth-weighted rates are used for WFS data from Sri Lanka; the variables entered into the regression equation include parity, educational level, residence, work experience since marriage and use of contraception since the birth. Contraception is not found to influence net breastfeeding rates in the 1st interval (1-16 months), although it is about as prevalent as in later intervals. The positive coefficients at intervals beyond the 1st also imply that contraceptive use is not a substitute for lactation in Sri Lanka or not a predominant one. Lifetime urban residence is associated with short durations of breastfeeding, and being an urban migrant is associated with intermediate durations relative to those of rural women. The effects of residence on breastfeeding are especially pronounced in the 1st interval. By parity as by contraception, differences in breastfeeding rates are not significant at short durations but become so with time as lower parity women reach pregnancy. Patterns by age are similar, but less sharp. Middle school attendance and work at home are both strongly associated with with lactation behavior, the former negatively and the latter to about an equal degree positively. Working outside the home seems not to influence breastfeeding to any great extent. In the multiple attribute regressions, middle schooling depresses breastfeeding durations about as strongly as lifetime urban residence relative to women who are rural and uneducated. Being at parity 5 or above or working at home almost as sharply increases durations. The use of contraception has slightly smaller positive effects. The patterns suggest that as Sri Lankan women become increasingly well educated and urban, and as family sizes decline, durations of breastfeeding will decline. Equally important however, even among better educated urban wives, breastfeeding continues longer than is typical of western countries.     

Isotopic evidence for breastfeeding and possible adult dietary differences from Late/Sub-Roman Britain

Historical documents indicate that breastfeeding and weaning practices have fluctuated in England through history. In order to obtain evidence for general breastfeeding patterns in Late/Sub-Roman Britain, stable carbon and nitrogen isotope values were measured in juvenile and adult skeletons (n = 87) from the cemetery of Queenford Farm, Dorchester-on-Thames, Oxfordshire. As the site contained few individuals between 0-1.5 years of age, it was not possible to determine the initial timing for the introduction of weaning foods. Between ages 2-4 years, the mean +/- SD delta(13)C results (-20.2 +/- 0.3 per thousand) are significantly more negative (t = -4.03, P < 0.001) compared to adult females (-19.7 +/- 0.3 per thousand). This is interpreted as evidence of a different diet being fed to children during weaning. After age 2, the delta(15)N values gradually decline, indicating complete cessation of breastfeeding by 3-4 years. Among adults, stature (males = 1.68 +/- 0.06 m; females = 1.58 +/- 0.07 m) and sexual dimorphism (106) were low, suggesting that the population was possibly under environmental stress. The delta(13)C results for adults are similar, but females show a small but statistically significantly (t = -2.86, P < 0.01) lower mean delta(15)N value (9.9 +/- 0.9 per thousand) compared to males (10.6 +/- 0.5 per thousand). These lower female delta(15)N values possibly reflect the different physiology of the sexes (pregnancy and/or lactation) or the reduced consumption of animal/fish protein by women, and this may have been influenced by individual preference, family needs, or societal values of the era.     

No evidence of association of oxytocin polymorphisms with breastfeeding in 2 independent samples

Oxytocin has an important function in breastfeeding via its role in the milk ejection reflex and in attachment and bonding processes. Genetic factors account for a significant part of the individual differences in breastfeeding behavior. OXT and OXTR have been proposed as gene candidates for breastfeeding. Previous studies have focused on certain single‐nucleotide polymorphisms (SNPs) within these genes, finding null or inconsistent results. The present study analyses the associations between a wide coverage of polymorphisms in OXT and OXTR and breastfeeding duration from 2 large and independent unselected samples comprising a total of 580 and 2112 female twin mothers from the Murcia Twin Registry (Spain) and QIMR Berghofer Medical Research Institute (Australia), respectively. A total of 19 SNPs in OXT and 137 in OXTR SNPs were covered in both samples. Effects of the OXT and OXTR polymorphisms on breastfeeding duration were calculated by means of linear regression controlling for age at survey time, educational level, interaction between age and educational level and principal components of genetic ancestry. The analyses were conducted independently in the 2 samples and also meta‐analyzed. Although some SNPs were associated at an alpha level of .05 with breastfeeding, they did not survive multiple testing correction. We conclude that SNPs within or nearby OXT and OXTR are unlikely to have large effects on breastfeeding behavior.     

Fertility in Pakistan during the 1970s

Evidence of trends in fertility and related variables in Pakistan during the 1970s is analyzed using data from 2 comparable surveys: the 1975 Pakistan Fertility Survey (PFS) and the 1979-80 Population, Labor Force and Migration Survey (PLM). Both suggest that fertility was fairly constant, with a total fertility rate around 7.0 until the 5-year period preceding the surveys (1970-74 and 1975-79, respectively), during which it declined abruptly. The apparent date of the decline is thus conflicting. The evidence of recent decline in each survey is likely to be spurious, the result of systematic distortions in the reporting of dates. The present research finds evidence that fertility as measured by age-specific and marital age-specific rates did not change in Pakistan during the 1970s, except for a decline in age group 15-19 as a result of delayed marriage. An analysis of levels and trends in selected components of fertility indicates that all subgroups, except literate women, show a rise in the average age at marriage of the order of 1/2 a year or so. Differentials between subgroups are in the expected direction, with literate women marrying later than illiterate ones and women in urban areas marrying later than those in rural areas. There is no notable change in the % of children being breastfed; however, the average duration of breastfeeding shows a non-trivial decline in all subgroups. Nonetheless prolonged breastfeeding is still the general practice. Current use of contraception at the time of the 2 surveys actually declined by 1980, while knowledge, reported ever-use, and fertility preferences all moved in a pronatalist direction. The lessons of this study are primarily methodological. In particular, the analysis of fertility change in the future in Pakistan will require either more reliable reporting of birth histories, or the continued piecing together of 2 or more surveys.     

Breast cancer-linked lncRNA u-Eleanor is upregulated in breast of healthy women with lack or short duration of breastfeeding

Recently, it has been revealed that estrogen-related reproductive factors are linked with some early gene expression lesions associated with malignancy in clinically healthy breasts. Accordingly, the aim of the current study was to evaluate the association of expression levels of estrogen-related long noncoding RNAs (lncRNAs) upstream Eleanor (u-Eleanor) and HOX antisense intergenic RNA (HOTAIR) with the different patterns of reproductive factors in breast tissue of healthy women. The subjects of this study were 98 cancer-free women who had undergone cosmetic mammoplasty. The expression levels of u-Eleanor and HOTAIR were measured using quantitative real-time polymerase chain reaction. The results of the current study showed that the women without a history of breastfeeding had a high-level expression of u-Eleanor compared with the women with a breastfeeding duration greater than 6 to 24 months (P = 0.03) as well as the women with a breastfeeding duration of more than 24 months (P = 0.005). Furthermore, a higher expression of u-Eleanor was found in the women with a short breastfeeding duration for 1 to 6 months than that in the women with a breastfeeding duration of greater than 24 months (P = 0.02). In the same way, the results of correlation test (r = −0.258; P = 0.036) and multivariate regression model (β = −0.321; P = 0.023) are indicative of a significant relationship of elevated expression of u-Eleanor with decreasing breastfeeding duration in the women. These findings could be important to identify the molecular mechanisms behind the relationship between a lack or short duration of the breastfeeding and the risk of breast cancer, which has previously been reported by epidemiological studies.     

Groundwater rise,soil salinization and the decline of Casuarina in southeastern Australia during the late Quaternary

Abstract The decline in interglacial importance of Casuarina over the late Quaternary across southeastern Australia is documented. Three previously proposed causes for the decline (change in fire regime, change to a wetter climate and competitive exclusion by eucalypts) are shown to be inadequate for explaining the majority of cases. Re-examination of the evidence shows the decline at most sites occurred synchronously with a rise in groundwater or soil salinization, or both. From a review of biological literature, it is established that Casuarina stricta, the main species considered to have been affected by the decline, is likely to be disadvantaged by high water tables and saline soils. A link is demonstrated between groundwater salinity and the nodulation status of Casuarina in Victoria. It is concluded that the late Quaternary Casuarina decline was caused by a combination of rising groundwater levels and soil salinization. Soil salinization and groundwater level must therefore be considered as major factors determining vegetation patterns in southeastern Australia through the Quaternary up to the present day.     

Breastfeeding in Saudi Arabia: a review

Background

Breastfeeding is viewed as the optimal method of infant feeding that provides many benefits to both the infant and the mother. The monitoring and reporting of breastfeeding indicators are essential for any country to plan and implement effective promotion programs for sustainable breastfeeding. The aim of this review is to examine the available studies and data on breastfeeding in Saudi Arabia, and determine the potential factors that affect breastfeeding practices and duration in this country.

Methods

The databases of Web of Knowledge, Science Direct and PubMed were searched using the relevant key words. Only studies that reported breastfeeding practices, rates and indicators in Saudi Arabia were included. Standard WHO definitions for breastfeeding categories were used in this review.

Results

Seventeen cross-sectional studies were identified and reviewed and five stated they used standard definitions. The self-administered questionnaire as a measurement tool was the predominant method of data collection. Infants' ages range from less than six months up to five years. Initiation rates were high (mostly above 90%), but a few studies reported low rates of timely initiation (within the first hour). The exclusive breastfeeding rate could not be accurately determined as rates range from 0.8% to 43.9% among studies due to the lack of clear definitions and the nature of study design. The partial (mixed) feeding method was common and the category of 'any breastfeeding' has generally high rates. The mean duration of breastfeeding has showed a progressive decline over time from 13.4 months in 1987 to 8.5 months in 2010. Factors associated with a high prevalence of breastfeeding and longer duration include increased maternal age, low educational levels, rural residence, low income, multiparity and avoiding contraceptives. The most common reason for breastfeeding cessation was insufficient breast milk. Other reasons include sickness, new pregnancy and breastfeeding problems.

Conclusions

Breastfeeding indicators in Saudi Arabia could not be monitored or compared relying on the available data because no longitudinal studies have been conducted in this country. A cohort study design would be the most appropriate procedure to rigorously assess and report valid results on breastfeeding practices and patterns in the Saudi society.     

Evidence of inflated exclusive breastfeeding estimates from a clinical trial in Bangladesh

Suboptimal breastfeeding is a major cause of infant morbidity and mortality across the world. Inconsistent data has hampered quantification of this practice, however, limiting breastfeeding promotion efforts. As part of a clinical trial in Dhaka, Bangladesh, data was collected on breastfeeding patterns among 125 infants. Infants were ages 4 to 12 weeks (mean?=?8.05, SD?=?2.13) at the time of enrollment, and breastfeeding data were collected at 24 study visits during a twelve-week period. Breastfeeding status was assessed using the WHO-recommended “current status” (24-h recall) method. These data were used to calculate two measures: a longitudinal estimate of exclusive breastfeeding since birth and a simulated cross-sectional prevalence to approximate common data collection methods. Infants were then ranked based on their breastfeeding status at all study visits and grouped into quartiles and compared using hospitalization data recorded for all infants as part of the original study. These data showed large differences in estimates of exclusive breastfeeding behaviors when assessed longitudinally (8.8% exclusive breastfeeding) vs. calculating a cross-sectional prevalence (56.2% exclusive breastfeeding). Additionally, when infants were grouped by quartile of breastfeeding behavior and matched with hospitalization records, it was found that infants in the lowest quartile of breastfeeding behaviors were significantly more likely to be hospitalized than infants in the highest quartile. These results provide further evidence that current breastfeeding epidemiology studies may overestimate rates of exclusive breastfeeding. They also provide further evidence to support the significant infant health benefits from breastfeeding promotion.Trial registration: ClinicalTrials.gov NCT01899378. Registered July 10, 2013.     

Studies on an overwintering population of the mushroom phorid Megaselia halterata (Diptera: Phoridae) parasitized by Howardula husseyi (Nematoda: Allantonematidae)

An overwintering population of the mushroom phorid fly Megaselia halterata parasitized by Howardula husseyi was studied in an attempt to explain the winter decline in incidence of parasitism that has been observed in flies from mushroom farms. Fly larvae from eggs hatching in November developed into pupae in December and flies emerged in May. No selective mortality of parasitized specimens of larvae, pupae, or flies was observed. Dead parasites were found in only 10% of parasitized flies. The incidence of parasitism in the emerging flies (50%) was five times that of their parental generation and although parasitism significantly delayed fly emergence the delay was only 2–3 days. There was no evidence of winter decline in parasitism; instead there was strong evidence that parasitism enhanced phorid survival through the winter.     

Factors affecting intention to breastfeed among Syrian and Jordanian mothers: a comparative cross-sectional study

Background

Breastfeeding remains normative and vital for child survival in the developing world. However, knowledge of the risk of Human Immunodeficiency Virus (HIV) transmission through breastfeeding has brought to attention the controversy of whether breastfeeding can be safely practiced by HIV positive mothers. Prevention of mother to child transmission (PMTCT) programs provide prevention services to HIV positive mothers including infant feeding counseling based on international guidelines. This study aimed at exploring infant feeding choices and how breastfeeding and the risk of HIV transmission through breastfeeding was interpreted among HIV positive mothers and their counselors in PMTCT programs in Addis Ababa, Ethiopia.

Methods

The study was conducted in the PMTCT clinics in two governmental hospitals in Addis Ababa, Ethiopia, using qualitative interviews and participant observation. Twenty two HIV positive mothers and ten health professionals working in PMTCT clinics were interviewed.

Results

The study revealed that HIV positive mothers have developed an immense fear of breast milk which is out of proportion compared to the evidence of risk of transmission documented. The fear is expressed through avoidance of breastfeeding or, if no other choice is available, through an intense unease with the breastfeeding situation, and through expressions of sin, guilt, blame and regret. Health professionals working in the PMTCT programs seemed to largely share the fear of HIV positive mother's breast milk, and their anxiety was reflected in the counseling services they provided. Formula feeding was the preferred infant feeding method, and was chosen also by HIV positive women who had to beg in the streets for survival.

Conclusions

The fear of breast milk that seems to have developed among counselors and HIV positive mothers in the wake of the HIV epidemic may challenge a well established breastfeeding culture and calls for public health action. Based on strong evidence of the risks when infants are not exclusively breastfed, there is a great need to protect breastfeeding from pressures of replacement feeding and to promote exclusive breastfeeding as the best infant feeding option for HIV positive and HIV negative mothers alike.     

Changes in breastfeeding initiation and duration in Peru, 1977–1986

Abstract

Both breastfeeding initiation and duration increased in Peru during 1977–86. Although one would have expected that the average incidence and duration of breastfeeding would have declined as a result of changes in population characteristics, the potential for an overall decline was more than overcome by changes in behavior. A net increase in initiation and duration is shown for all subgroups of interest. The largest absolute increases are documented for children who, in 1977, were the least likely to be breastfed and who were breastfed for the shortest durations.     

Mental health, attachment and breastfeeding: implications for adopted children and their mothers

ABSTRACT : Breastfeeding an adopted child has previously been discussed as something that is nice to do but without potential for significant benefit. This paper reviews the evidence in physiological and behavioural research, that breastfeeding can play a significant role in developing the attachment relationship between child and mother. As illustrated in the case studies presented, in instances of adoption and particularly where the child has experienced abuse or neglect, the impact of breastfeeding can be considerable. Breastfeeding may assist attachment development via the provision of regular intimate interaction between mother and child; the calming, relaxing and analgesic impact of breastfeeding on children; and the stress relieving and maternal sensitivity promoting influence of breastfeeding on mothers. The impact of breastfeeding as observed in cases of adoption has applicability to all breastfeeding situations, but may be especially relevant to other at risk dyads, such as those families with a history of intergenerational relationship trauma; this deserves further investigation.     

Effects of breastfeeding on trajectories of body fat and BMI throughout childhood

Objective: To investigate the effect of breastfeeding in healthy boys and girls on their trajectories of percent body fat (%BF) and BMI standard deviation scores (BMI–SDS) throughout childhood. Methods and Procedures: Analyses of the DOrtmund Nutritional and Anthropometric Longitudinally Designed (DONALD) Study included data from 219 male and 215 female term participants, born between 1984 and 1999, with repeated anthropometric measurements between 0.5 and 7 years and prospective data on duration of breastfeeding. Results: Among boys with an overweight mother (OW‐M), analyses adjusted for potential confounders revealed that not or shortly breastfed (≤17 weeks) boys did not experience the age‐dependent decrease in %BF seen in all children with normal weight mothers (NW‐Ms). In contrast, boys fully breastfed for >17 weeks were protected against the adverse effect of maternal overweight (effect of long breastfeeding vs. no/short breastfeeding among boys with OW‐Ms: 0.46%/year; s.e. 0.18; P = 0.01). There was also a suggestion of an interaction between maternal overweight and breastfeeding for the BMI–SDS trajectory (0.08 SDS/year; s.e. 0.04; P = 0.07). Among boys with NW‐Ms mothers and the corresponding subgroups of girls, breastfeeding had little effect on the development of %BF or BMI–SDS throughout childhood. Discussion: Our study suggests that breastfeeding could offset a potential programming effect for childhood adiposity among boys with OW‐Ms, to whom advice to breast‐feed should thus be specifically targeted.     

Why does photosynthesis decrease with needle age in Pinus pinaster?

Rates of photosynthesis vary with foliage age and typically decline from full-leaf expansion until senescence occurs. This age-related decline in photosynthesis is especially important in species that retain foliage for several years, yet it is not known whether the internal conductance to CO₂ movement (g _i) plays any role. More generally, g _i has been measured in only a few conifers and has never been measured in leaves or needles older than 1 year. The effect of ageing on g _i was investigated in Pinus pinaster, a species that retains needle for 4 or more years. Measurements were made in autumn when trees were not water limited and after leaf expansion was complete. Rates of net photosynthesis decreased with needle age, from 8 μmol m⁻² s⁻¹ in fully expanded current-year needles to 4.4 μmol m⁻² s⁻¹ in 3-year-old needles. The relative limitation due to internal conductance (0.24–0.35 out of 1) was in all cases larger than that due to stomatal conductance (0.13–0.19 out of 1). Internal conductance and stomatal conductance approximately scaled with rates of photosynthesis. Hence, there was no difference among year-classes in the relative limitations posed by internal and stomatal conductance or evidence that they cause the age-related decline in photosynthesis. There was little evidence that the age-related decline in photosynthesis was due to decreases in contents of N or Rubisco. The decrease in rates of photosynthesis from current-year to older needles was instead related to a twofold decrease in rates of photosynthesis per unit nitrogen and V _cmax/Rubisco (i.e., in vivo specific activity).     

Breast-feeding in Bangladesh

In this paper the duration of breastfeeding is examined in relation to demographic and socioeconomic characteristics of women and households. 98% of Bangladesh mothers breastfeed their children from birth. In data from the Bangladesh Fertility Survey conducted in 1975-1976 on 4998 live births, the mean duration of breastfeeding was 27.3 months. Duration of breastfeeding was positively related with the age of women. Female children were breastfed for periods about 5 months shorter than male children. Children born to urban mothers were breastfed for shorter durations than children born to rural mothers of all age groups. The duration of breastfeeding decreased with the increase of education of the mother. Promotion of breastfeeding should be a primary responsibility of family planning clinics. Further decline in the duration of breastfeeding would increase levels of fertility and infant and child mortality.     

Cost-Effectiveness of Peer Counselling for the Promotion of Exclusive Breastfeeding in Uganda

Background

Community based breastfeeding promotion programmes have been shown to be effective in increasing breastfeeding prevalence. However, there is limited data on the cost-effectiveness of these programmes in sub-Saharan Africa. This paper evaluates the cost-effectiveness of a breastfeeding promotion intervention targeting mothers and their 0 to 6 month old children.

Methods

Data were obtained from a community randomized trial conducted in Uganda between 2006–2008, and supplemented with evidence from several studies in sub-Saharan Africa. In the trial, peer counselling was offered to women in intervention clusters. In the control and intervention clusters, women could access standard health facility breastfeeding promotion services (HFP). Thus, two methods of breastfeeding promotion were compared: community based peer counselling (in addition to HFP) and standard HFP alone. A Markov model was used to calculate incremental cost-effectiveness ratios between the two strategies. The model estimated changes in breastfeeding prevalence and disability adjusted life years. Costs were estimated from a provider perspective. Uncertainty around the results was characterized using one-way sensitivity analyses and a probabilistic sensitivity analysis.

Findings

Peer counselling more than doubled the breastfeeding prevalence as reported by mothers, but there was no observable impact on diarrhoea prevalence. Estimated incremental cost-effectiveness ratios were US$68 per month of exclusive or predominant breastfeeding and U$11,353 per disability adjusted life year (DALY) averted. The findings were robust to parameter variations in the sensitivity analyses

Conclusions

Our strategy to promote community based peer counselling is unlikely to be cost-effective in reducing diarrhoea prevalence and mortality in Uganda, because its cost per DALY averted far exceeds the commonly assumed willingness-to-pay threshold of three times Uganda’s GDP per capita (US$1653). However, since the intervention significantly increases prevalence of exclusive or predominant breastfeeding, it could be adopted in Uganda if benefits other than reducing the occurrence of diarrhoea are believed to be important.     

Longitudinal study of breastfeeding structure and women's work in the Brazilian Amazon

It is well established that breast milk is the ideal food for infants and that breastfeeding has short‐ and long‐term health benefits for the mother and child. However, there is variation in breastfeeding patterns between populations. Women's work is thought to influence breastfeeding patterns and timing of supplementation and it is often assumed that women in subsistence‐oriented societies can more easily integrate their productive and reproductive activities. This article reports longitudinal data, collected in three rounds (resguardo [<40 days], peak [2–4 months], and late [14–16 months] lactation), on breastfeeding structure, infant care, and work patterns of 17 rural Amazonian women in an effort to understand how breastfeeding structure and maternal time allocation changed over time, as well as the strategies women used to integrate their productive and reproductive roles. Women breastfed 10.6 ± 3.1, 9.4 ± 3.4, and 9.6 ± 5.5 times per 9‐h period in the three rounds, respectively. Breastfeeding structure, specifically session duration, changed over time (P < 0.05). As lactation progressed, women spent less time breastfeeding and in infant care and more time in subsistence work. In peak lactation, subsistence work was negatively correlated with infant care (r = ?0.4, P = 0.01), breastfeeding (r = ?0.29, P = 0.05) and session duration (r = ?0.39, P < 0.01) and in late lactation was negatively correlated with time spent breastfeeding (r = ?0.39, P < 0.01) and in infant care (r = ?0.50, P < 0.01) and positively correlated with inter‐session interval (r = 0.40, P < 0.01). Generally, women reduced time in subsistence work when breastfeeding was more intense and returned to normal activity patterns once infants were being supplemented. The costs and benefits associated with women's strategies are discussed. Am J Phys Anthropol, 2011. © 2010 Wiley‐Liss, Inc.