Differences In Infant Mortality Research Articles

Losing the female survival advantage: Sex differentials in infant and child mortality in Pakistan

Losing the female survival advantage: Sex differentials in infant and child mortality in Pakistan

The Effects of Race, Ethnicity, and Maternal Education on Infant Mortality.

The state of New Jersey has a large Black/African American (AA) versus White racial disparity in infant mortality and educational level at childbirth. This disparity, measured by rate ratio, increases with greater maternal education among varied racial-ethnic groups. The nature of this disparity measured by rate differences has not been explored. Infant birth and mortality data were used to examine whether racial or ethnic disparities in infant mortality increased with greater maternal education, comparing rate differences and rate ratios. Racial and ethnic variations in the association between maternal education and infant mortality were examined. Data were from the New Jersey State Health Assessment Data for all New Jersey births between 2014 and 2018 stratified by race and ethnicity, maternal education, and infant mortality ( n = 481,333). R software was used to create a data set and estimate additive and multiplicative interactions, rate differences, and rate ratios for infant mortality by maternal race/ethnicity and educational levels among four racial-ethnic groups. Infant mortality was significantly greater for Black/AA and Hispanic mothers than for White mothers. At all educational levels, Black/AA mothers had the highest prevalence of infant mortality compared to other racial or ethnic groups. Rate differences in infant mortality showed a decrease in Black/AA-White differences for mothers with a high school education or less compared to mothers with a college degree. However, rate ratios showed an increase in Black/AA-White ratio with increasing education levels for mothers with high school education or less than mothers with a college degree. Risk ratios comparing infant mortality for Black/AA versus Hispanic or Asian mothers showed more than a twofold greater risk at all education levels for Black/AA infants. Finally, college-educated Black/AA mothers had significantly higher rates of infant mortality than White or Hispanic mothers with a high school education or less. Black/AA mothers with a college degree had a higher infant mortality rate than White, Hispanic, or Asian mothers with a high school education or less. Future research should address contextual/systemic contributors to this disparity.

Health Insurance and Differences in Infant Mortality Rates in the US

Health insurance status is associated with differences in access to health care and health outcomes. Therefore, maternal health insurance type may be associated with differences in infant outcomes in the US. To determine whether, among infants born in the US, maternal private insurance compared with public Medicaid insurance is associated with a lower infant mortality rate (IMR). This cohort study used data from the Centers for Disease Control and Prevention (CDC) Wide-Ranging Online Data for Epidemiologic Research expanded linked birth and infant death records database from 2017 to 2020. Hospital-born infants from 20 to 42 weeks of gestational age were included if the mother had either private or Medicaid insurance. Infants with congenital anomalies, those without a recorded method of payment, and those without either private insurance or Medicaid were excluded. Data analysis was performed from June 2022 to August 2023. Private vs Medicaid insurance. The primary outcome was the IMR. Negative-binomial regression adjusted for race, sex, multiple birth, any maternal pregnancy risk factors (as defined by the CDC), education level, and tobacco use was used to determine the difference in IMR between private and Medicaid insurance. The χ2 or Fisher exact test was used to compare differences in categorical variables between groups. Of the 13 562 625 infants included (6 631 735 girls [48.9%]), 7 327 339 mothers (54.0%) had private insurance and 6 235 286 (46.0%) were insured by Medicaid. Infants born to mothers with private insurance had a lower IMR compared with infants born to those with Medicaid (2.75 vs 5.30 deaths per 1000 live births; adjusted relative risk [aRR], 0.81; 95% CI, 0.69-0.95; P = .009). Those with private insurance had a significantly lower risk of postneonatal mortality (0.81 vs 2.41 deaths per 1000 births; aRR, 0.57; 95% CI, 0.47-0.68; P < .001), low birth weight (aRR, 0.90; 95% CI, 0.85-0.94; P < .001), vaginal breech delivery (aRR, 0.80; 95% CI, 0.67-0.96; P = .02), and preterm birth (aRR, 0.92; 95% CI, 0.88-0.97; P = .002) and a higher probability of first trimester prenatal care (aRR, 1.24; 95% CI, 1.21-1.27; P < .001) compared with those with Medicaid. In this cohort study, maternal Medicaid insurance was associated with increased risk of infant mortality at the population level in the US. Novel strategies are needed to improve access to care, quality of care, and outcomes among women and infants enrolled in Medicaid.

Socio-economic differentials of under-five mortality in Botswana: an application of the indirect estimation method

Abstract Background Socio-economic differentials in infant and under-five mortality exist in all countries worldwide, but the extent of differentials varies across countries. This study aimed to examine the socio-economic differentials of under-five mortality in Botswana within the framework of equality and equity. Methods and findings The analysis for this paper was based on the data from 2001 and 2011 Botswana Population and Housing Censuses and the 2017 Botswana Demographic Survey. One census method was used to indirectly estimate under-five mortality for different socio-economic groups using Princeton west model life tables. Results from this study revealed that socio-economic disparities in under-five mortality disfavouring the worse-off exist in all the selected socio-economic variables. The variations of socio-economic groups by mother’s place of residence and employment status have been narrowing over time, whereas the differences of socio-economic groups by mother’s level of education and marital status have been widening over time. Conclusions The findings of this study show that policies and interventions targeted at reducing inequalities should reach all socioeconomic groups across the country. Differences of each society and localities should be considered while designing and implementing policies and interventions.

Reducing infant and child mortality: assessing the social inclusiveness of child health care policies and programmes in three states of India

BackgroundEven though the overall infant mortality rate and child mortality rate have considerably declined in India, the marginalised groups-Scheduled Caste, and Scheduled Tribe, continue to have higher mortality rates. This study looks at the changes in IMR and CMR amongst disadvantaged and advanced social groups at the national level and in three states of India.Data and methodsData from five rounds of National Family Health Survey spanning nearly three decades have been used to measure IMR and CMR according to the social groups for India and for selected states-Bihar, West Bengal, and Tamil Nadu. The relative hazard curves were drawn to understand which social group’s children face a higher risk of dying in the first year of birth and between first year and age four in those three states. Further, a log-rank test was applied to examine whether the differences between the survival curves or distributions of the three social groups are statistically significant. Finally, the binary logit regression model was applied to investigate the effect of ethnicity, and other socio-economic and demographic covariates on the risk of infant and child deaths (1–4 years) in the country and in selected states.ResultsHazard curve shows the probability of death within one year of birth was highest among the children belonging to the ST families, followed by SCs in India. And, the CMR was found to be higher amongst the STs compared to all other social groups as well at the national level. While Bihar had a remarkably high infant and child mortality rates, Tamil Nadu possessed the lowest child death rates irrespective of class, caste, and religion. The regression model revealed that most of the caste/tribe gaps in infant and child deaths might be attributed to the place of residence, mother’s level of education, economic status, and the number of children in a family. Notably, the multivariate analysis showed that ethnicity was an independent risk factor, when controlled for socioeconomic status.ConclusionThe study detects the persistence of significant caste/tribe differentials in infant and child mortality in India. Poverty, education and health care access issues could be the possible reasons for the premature deaths of the children from deprived castes and tribes. There is a need to critically analyse the current health programmes aimed at reducing IMR and CMR to make them attuned to the needs of the marginalised communities.

Trends and Racial and Geographic Differences in Infant Mortality in the United States Due to Necrotizing Enterocolitis, 1999 to 2020

This cohort study analyzes yearly trends in necrotizing enterocolitis–related infant mortality rates (NEC-IMR) from 1999 to 2020, overall and by Black and White race, and described Black-to-White NEC-IMR ratios and NEC-IMR for US states.

THE CONTRIBUTION OF THE GEOGRAPHICAL AREA OF RESIDENCE ON RURAL-URBAN DIFFERENTIALS IN INFANT MORTALITY IN KAKAMEGA CENTRAL SUB-COUNTY, KAKAMEGA COUNTY, KENYA

Background: Infant mortality remains an indaba in Sub-Saharan Africa, a region currently producing over half of global infant deaths. Kakamega Central Sub-County, a region within Sub-Saharan Africa, has an infant mortality rate of 37. This study examined the contribution of the geographical area of residence on rural-urban differentials in infant mortality in Kakamega Central Sub-County, Kakamega County, Kenya. Methods: A cross-sectional research design was adopted. Primary data were collected from mothers between the childbearing ages of 15 to 49 years who had an experience of childbirth between 2013 and 2022. Secondary data were obtained from the 2019 Kenya population and housing census. Cross-tabulation and multinomial logistic regression analyses were conducted on the statistical package of the social sciences version 25 computer software program. Results: Rural areas with mud roads had higher odds of neonatal (aOR – 2.067) and infant (aOR - 3.867) mortalities when compared to those with tarmacked roads. Areas with 3 to 4 health facilities had 8.248 and 2.651 higher adjusted odds ratios of post-neonatal and infant mortality when compared to areas with at least 5 health facilities in rural and urban areas, respectively. Residing in good housing was associated with lower odds ratios of rural neonatal (aOR – 0.016), urban post-neonatal (aOR – 0.265), and infant (aOR – 0.312) mortalities when compared to residing in durable housing. Conclusion: There is a need for concerted efforts towards road improvement in rural areas; increased access to functional and well-equipped health to ensure an acceptable density of health facilities; and enlightening people on the importance of proper hygiene in the household environments and on good, affordable, dietary practices.

Sex-Biased Differences in Infant Mortality and Life Expectancy at Síi Túupentak , an Ancestral Ohlone Village in Central California (ca. 540–145 cal. BP)

ABSTRACT: Síi Túupentak (CA-SCA-565/H) is a late precontact ancestral Ohlone village and cemetery site in Central California (ca. 540–145 cal. BP). Integration of proteomic, genomic, and osteological analyses provided highly confident biological sex estimates for remains of most individuals at this site (65 of 76), spanning all age groups, from perinatal infants to aged adults. Based on these relatively comprehensive data, it was possible to generate sex-specific Kaplan-Meier survival curves for this burial population of sedentary hunter-gatherers. As was common among societies predating modern Western medicine and antibiotics, infant mortality was high for both males and females. However, male infants (from birth to 5 years of age) appear to have died at nearly twice the rate of female infants (10 of 33 males vs. 5 of 32 females) and had a mean age of survival at birth of only 19 years, compared to 30 years for females. The difference in male and female survival was statistically significant by log-rank test ( p = 0.005). Compared to survival curves for other societies predating modern Western medicine and antibiotics, including American-era historical deaths recorded for a cemetery in San Francisco, this bias is larger than might be expected. We suspect the pattern of sex-biased infant mortality at Síi Túupentak could relate to an intrinsic survival advantage for female infants, combined with extrinsic factors such as environmental pathogens, nutritional stress, and gendered differences in weaning patterns detected through stable isotope analyses. Using isotopic data on weaning ages and ethnographic accounts of gendered foraging activities, we focus on the potential role of sex-biased differences in weaning patterns and highlight potential demographic and social implications. Broader application of proteomic and genomic sex estimation would allow sex-biased differences in nutrition and health, as well as social and cultural aspects of male and female life histories, to be compared across a wide range of archaeologically known hunter-gatherer societies.

Inferring “missing girls” from child sex ratios in historical census data

The topic of “missing girls” in historical Europe has not only been mostly neglected, but previous research addressing this issue usually took the available information too lightly, either rejecting or accepting the claims that there was discrimination against female children, without assessing the possibility that the observed child sex ratios could be attributable to chance, mortality differentials, or registration quality. This article contributes to this discussion by (1) using a novel dataset of historical child sex ratios that covers a large part of the European geography between 1700 and 1926; and (2) explicitly considering the effects of random variability, demographic variation, and faulty enumeration in the analysis. Our results provide evidence that some of these European populations had child sex ratios well above the levels usually considered “natural”. Although part of this variation is indeed shown to be due to random noise and structural features related to infant mortality differentials and census quality, some of the observed sex ratios are too high to be attributed solely to these proximate factors. Thus, these findings suggest that there are behavioural explanations for some of the unbalanced sex ratios observed in our data.

Birthweight, gestational age and familial confounding in sex differences in infant mortality: a matched co-twin control study of Brazilian male-female twin pairs identified by population data linkage.

BackgroundIn infancy, males are at higher risk of dying than females. Birthweight and gestational age are potential confounders or mediators but are also familial and correlated, posing epidemiological challenges that can be addressed by studying male-female twin pairs.MethodsWe studied 28 558 male-female twin pairs born in Brazil between 2012 and 2016, by linking their birth and death records. Using a co-twin control study matched for gestational age and familial factors, we applied logistic regression with random effects (to account for paired data) to study the association between male sex and infant death, adjusting for: birthweight, within- and between-pair effects of birthweight, birth order and gestational age, including interactions. The main outcome was infant mortality (0–365 days) stratified by neonatal (early and late) and postneonatal deaths.ResultsMales were 100 g heavier and more at risk of infant death than their female co-twins before [odds ratio (OR) = 1.28, 95% confidence interval (CI): 1.11–1.49, P = 0.001] and after (OR = 1.60, 95% CI: 1.39–1.83, P <0.001) adjusting for birthweight and birth order. When adjusting for birthweight within-pair difference and mean separately, the OR attenuated to 1.40 (95% CI: 1.21–1.61, P <0.001), with evidence of familial confounding (likelihood ratio test, P <0.001). We found evidence of interaction (P = 0.001) between male sex and gestational age for early neonatal death.ConclusionsAfter matching for gestational age and familial factors by design and controlling for birthweight and birth order, males remain at greater risk of infant death than their female co-twins. Birthweight’s role as a confounder can be partially explained by familial factors.

U.S. Infant Mortality Rates: An Exploration of Black/White Disparities, Current Trends, and Social Inequalities

The purpose of this paper is to explore 10-year trends in infant mortality rates (IMRs) from 2007 to 2016 for non-Hispanic (NH) blacks and NH whites by levels of sociodemographic characteristics such as maternal age, marital status, education, and access to prenatal care. Using data from the Centers for Disease Control and Prevention (CDC) Wonder Online database, descriptive statistics were performed, and a measure of disparity was calculated to illustrate racial differences in IMRs. Between 2007 and 2016, IMRs for NH blacks have declined at a faster rate (15.8%) compared to NH whites (13.5%). As for the selected sociodemographic indicators, reductions were observed for both racial groups for most age categories assessed, married and unmarried women, and for women with early or no access to prenatal care. For educational attainment levels, declines were observed for both racial groups for all levels except for high school graduate or GED and some college, in which increases were observed for NH white women. The measure of disparity illustrates the large racial gap in IMRs persists between NH blacks and NH whites. More structural and systemic mechanisms, including research and policies, are needed to address the disparities in IMRs.

Women’s empowerment and infant mortality in Latin America: evidence from 286 cities

ABSTRACT Levels of women’s empowerment (WE) can contribute to differences in infant mortality rates (IMRs) across cities. We used a cross-sectional multilevel study to examine associations of WE with IMRs across 286 cities in seven Latin American countries. We estimated IMRs for 2014–2016 period and combined city socioeconomic indicators into factors reflecting living conditions and service provision. WE was operationalized: (1) in cities, by using scores for women’s labor force participation (WLFP) and educational attainment among women derived from education and employment indicators disaggregated by sex; (2) in countries, by including a scale of enforcements of laws related to women’s rights. We estimated adjusted percent differences in IMRs associated with higher WE scores across all cities and stratified by country GDP. We found substantial heterogeneity in IMRs and WE across cities. Higher WLFP was associated with lower IMRs. Higher women’s educational attainment was associated with lower IMRs only in cities from countries with lower GDP. Poorer national enforcement of laws protecting women’s rights was associated with higher IMRs in all countries. Women’s empowerment could have positive implications for population health. Fostering women’s socioeconomic development and girls’ education should be part of strategies to reduce IMRs in cities of Global South.

Residential inequality and spatial patterns of infant mortality in Ethiopia: evidence from Ethiopian Demographic and Health Surveys

BackgroundDespite the remarkable decrease in infant mortality rate in most countries, the rate of decline is slow and it remains unacceptably high in Sub-Saharan Africa. The progress in infant mortality in Ethiopia is far below the rate needed to achieve the Sustainable Development Goal. Understanding the residential inequality and spatiotemporal clusters of infant mortality is essential to prioritize areas and guide public health interventions. Therefore, this study aimed to investigate the residential inequality and spatial patterns of infant mortality in Ethiopia.MethodsA secondary data analysis was done based on the Ethiopian demographic and health surveys conducted in 2000, 2005, 2011, and 2016. A total weighted sample of 46,317 live births was included for the final analysis. The residential inequality was assessed by calculating the risk difference in infant mortality rates between urban and rural live births and presented using a forest plot. For the spatial patterns of infant mortality, the SaTScan version 9.6 and ArcGIS version 10.6 statistical software were used to identify the spatial patterns of infant mortality.ResultsThe study revealed that the infant mortality rate significantly declined from 96.9 per 1000 live births [95% CI 93.6, 104.2] in 2000 to 48.0 per 1000 live births [95% CI 44.2, 52.2] in 2016 with an annual rate of reduction of 3.2%. The infant mortality rate has substantial residential inequality over time, which is concentrated in the rural area. The spatial distribution of infant mortality was significantly clustered at the national level in survey periods (global Moran’s I, 0.04–0.081, p value < 0.05). In 2000, the most likely clusters were found in east Afar and at the border areas of south Amhara and north Oromia regions (LLR = 7.61, p value < 0.05); in 2005, at the border areas of Southern Nations Nationalities and People and in the entire Amhara region (LLR = 10.78, p value< 0.05); in 2011, at Southern Nations Nationalities and People and Gambella regions (LLR = 6.63, p value< 0.05); and in 2016, at east Oromia and northeast Somali regions (LLR = 8.38, p value < 0.05).ConclusionIn this study, though infant mortality has shown remarkable reduction, infant mortality remains a major health care concern and had significant spatial variation across regions. Besides, the study found that infant mortality was highly concentrated in rural areas. Identifying the hotspot areas of infant mortality would help in designing effective interventions to reduce the incidence of infant mortality in these areas. Therefore, the findings highlighted that public health interventions should target rural areas and identified hotspot areas to reduce the incidence of infant mortality.

Structural racism, racial inequities and urban–rural differences in infant mortality in the US

BackgroundWhile evidence shows considerable geographic variations in county-level racial inequities in infant mortality, the role of structural racism across urban–rural lines remains unexplored. The objective of this study was to...

Infant Mortality Rates for Farming and Unemployed Households in the Japanese Prefectures: An Ecological Time Trend Analysis, 1999-2017.

BackgroundRecent research suggests that Japanese inter-prefecture inequality in the risk of death before reaching 5 years old has increased since the 2000s. Despite this, there have been no studies examining recent trends in inequality in the infant mortality rate (IMR) with associated socioeconomic characteristics. This study specifically focused on household occupation, environment, and support systems for perinatal parents.MethodsUsing national vital statistics by household occupation aggregated in 47 prefectures from 1999 through 2017, we conducted multilevel negative binomial regression analysis to evaluate occupation/IMR associations and joinpoint analysis to observe temporal trends. We also created thematic maps to depict the geographical distribution of the IMR.ResultsCompared to the most privileged occupations (ie, type II regular workers; including employees in companies with over 100 employees), IMR ratios were 1.26 for type I regular workers (including employees in companies with less than 100 employees), 1.41 for the self-employed, 1.96 for those engaged in farming, and 6.48 for unemployed workers. The IMR ratio among farming households was 1.75 in the prefectures with the highest population density (vs the lowest) and 1.41 in prefectures with the highest number of farming households per 100 households (vs the lowest). Joinpoint regression showed a yearly monotonic increase in the differences and ratios of IMRs among farming households compared to type II regular worker households. For unemployed workers, differences in IMRs increased sharply from 2009 while ratios increased from 2012.ConclusionsInter-occupational IMR inequality increased from 1999 through 2017 in Japan. Further studies using individual-level data are warranted to better understand the mechanisms that contributed to this increase.

A Participatory, State-Community-Academic Model to Improve Pregnancy Outcomes in Texas: The Healthy Families Initiative.

While the Texas infant mortality rate (IMR) is below the Healthy People 2020 objective (5.7 per 1,000 live births), stark differences in IMR are seen across Texas communities. Health indicators for the state suggest important missed opportunities for improving maternal and infant outcomes. The Healthy Families initiative was a collaboration between a Texas state agency, community partners, and academic institutions to understand how evidence-based interventions could be identified, adapted, and implemented to address community priorities and reduce disparities in pregnancy outcomes. The Healthy Families initiative included two Texas counties, one with low utilization of prenatal care and one with persistent disparities in infant mortality. The model served to (1) identify community factors influencing IMR and maternal morbidity through stakeholder engagement and secondary data, (2) build community capacity to link pregnant women with existing and newly developed services, and (3) develop partnerships within the community and clinics to improve access to and sustainability of services. A community-based participatory approach focused on stakeholder engagement was used to identify, design, and adapt strategies to address community-identified priorities. The Healthy Families initiative is a unique state-community-academic partnership aimed at improving pregnancy outcomes in vulnerable communities, with a focus on promotion of capacity building, maintenance, and sustainability of maternal and infant health programs.

Sex Differences in Infant Mortality: A Population Data Linkage Study of Brazilian Male-Female Twin Pairs

IntroductionEpidemiological studies of twin pairs provide researchers with the opportunity to better understand the roles of genetics and the environment on human traits and health conditions. Twin births are also of interest for public health, given they are five times more likely to be of low birth weight and preterm compared to singletons. Male twin newborns are at high risk of mortality, although the causes of such disadvantage are still largely unknown.&#x0D; Objectives and ApproachWe deterministically linked population birth to death records of twins born in Brazil from 2012–2016, and probabilistically linked twins within pairs through a bespoke algorithm. We studied male-female twin pairs to investigate sex differences in infant mortality stratified by early neonatal (0–6 days), late neonatal (7–27 days) and late infant (28–365 days) deaths. We used conditional logistic regression to estimate odds ratios (OR) for male sex, adjusting for birth weight and matching for familial factors by design.&#x0D; ResultsOur algorithm successfully matched 101,382 twin pairs, 28,558 were male-female pairs included in the study. Average birthweight was 100g greater for males compared with females. We found that males were at higher risk of infant mortality than their female co-twins even after adjusting for birth weight and familial factors (aOR = 1.42, 95% CI: 1.22–1.66). The aORs for neonatal death increased from those born at less than 28 weeks to those born at 28–31, 32–26 and 37+ weeks: 1.47 (1.02–2.13), 1.73 (1.17–2.57), 1.99 (1.17–3.38), and 3.35 (1.29–8.73), respectively.&#x0D; Conclusion / ImplicationsMale twins have greater risk of infant and neonatal mortality compared with female co-twins, more so the higher the gestational age. Unmeasured familial and maternal factors may influence the role of birth weight in the association between sex and poor early life outcomes.

Characterising variability and predictors of infant mortality in urban settings: findings from 286 Latin American cities

BackgroundUrbanisation in Latin America (LA) is heterogeneous and could have varying implications for infant mortality (IM). Identifying city factors related to IM can help design policies that promote infant health...

Gender differentials and risk of infant and under five mortality in India. A comparative survival analysis

• Infant mortality rate (IMR) and under five mortality rate (U5MR) are vital indicators of the health of a population. • For U5MR, mother ’s age, birth order, and birth interval are significant factors, as discussed before. Parental education is an important factor for U5MR. • This paper focused more on the gender differential in child survival by selected sociodemographic and economic factors. Future research can take care of this limitation and take a holistic approach to child survival analysis. • Infant mortality rate (IMR) and under five mortality rate (U5MR) are vital indicators of the health of a population. • For U5MR, mother ’s age, birth order, and birth interval are significant factors, as discussed before. Parental education is an important factor for U5MR. • This paper focused more on the gender differential in child survival by selected sociodemographic and economic factors. Future research can take care of this limitation and take a holistic approach to child survival analysis. Infant mortality rate (IMR) and under five mortality rate (U5MR) are vital indicators of the health of a population. Included in the Sustainable Development Goals (SDGs), they are, together with health and nutrition status, considered significant indicators of child well-being. In India, during the period 1990 to 2015, female IMR declined from 81 to 39 deaths per 1000 live births, while male IMR declined from 78 to 35. Further decline was reported by SRS 2018 (Female IMR 33, Male IMR 32). However, the female-male gap in IMR continues to persist. The aim of the present study is to assess the gender disparities in and the risk of infant and under five mortality in India. The study used data from the fourth round of the National Family Health Survey (NFHS-4, 2015–16). The study revealed that the risk of under-five mortality was higher among males. The pattern of sex differences in infant mortality appears to be the same across India, while that of under-five mortality shows slight differences among males and females. The findings of this study suggest that though socioeconomic characteristics appear to significantly influence infant mortality, sex differences in infant mortality are not influenced by these factors. These findings will enable policymakers and public health practitioners to develop cost-effective interventions targeting the sub-populations of children at risk.

The Effect of Infant's Sex on Human Milk Macronutrients Content: An Observational Study.

Background: Sex differences in infant mortality and neonatal morbidity have been previously documented. Few studies, with conflicting results, have investigated the interaction between human milk (HM) macronutrients and energy content and infant sex. Objective: To test the null hypothesis that HM macronutrients content will not be affected by infant's sex. Materials and Methods: We compiled previously generated data on macronutrients content of colostrum samples and mature milk samples collected from lactating mothers of healthy term infants. Macronutrient content was measured using mid-infrared spectroscopy. Results: A total of 324 milk samples were included in the analysis consisting of 189 colostrum and 135 mature milk samples. There were 92 female and 97 male infants in the colostrum group and 65 female and 70 male infants in the mature milk group. Maternal age, gestational age, mode of delivery and percentage of large for gestational age, small for gestational age, and appropriate for gestational age were similar between female and male groups at all stages of lactation. Birth weight in male infants was significantly higher than in female infants (3389.5 ± 444.6 versus 3229.2 ± 415 g, p = 0.016). There were no statistically significant differences in macronutrient contents between the female and male groups at all stages studied. Conclusion: Macronutrients and energy content in colostrum and mature milk collected from mothers of term infants were unaffected by the sex of their offspring.