Although the health benefits of breastfeeding are widely acknowledged, opinions and recommendations are strongly divided on the optimal duration of exclusive breastfeeding. Since 2001, the World ...Health Organization has recommended exclusive breastfeeding for six months. Much of the recent debate in developed countries has centred on the micronutrient adequacy, as well as the existence and magnitude of health benefits, of this practice.
To assess the effects on child health, growth, and development, and on maternal health, of exclusive breastfeeding for six months versus exclusive breastfeeding for three to four months with mixed breastfeeding (introduction of complementary liquid or solid foods with continued breastfeeding) thereafter through six months.
We searched The Cochrane Library (2011, Issue 6), MEDLINE (1 January 2007 to 14 June 2011), EMBASE (1 January 2007 to 14 June 2011), CINAHL (1 January 2007 to 14 June 2011), BIOSIS (1 January 2007 to 14 June 2011), African Index Medicus (searched 15 June 2011), Index Medicus for the WHO Eastern Mediterranean Region (IMEMR) (searched 15 June 2011), LILACS (Latin American and Caribbean Health Sciences) (searched 15 June 2011). We also contacted experts in the field.The search for the first version of the review in 2000 yielded a total of 2668 unique citations. Contacts with experts in the field yielded additional published and unpublished studies. The updated literature review in December 2006 yielded 835 additional unique citations.
We selected all internally-controlled clinical trials and observational studies comparing child or maternal health outcomes with exclusive breastfeeding for six or more months versus exclusive breastfeeding for at least three to four months with continued mixed breastfeeding until at least six months. Studies were stratified according to study design (controlled trials versus observational studies), provenance (developing versus developed countries), and timing of compared feeding groups (three to seven months versus later).
We independently assessed study quality and extracted data.
We identified 23 independent studies meeting the selection criteria: 11 from developing countries (two of which were controlled trials in Honduras) and 12 from developed countries (all observational studies). Definitions of exclusive breastfeeding varied considerably across studies. Neither the trials nor the observational studies suggest that infants who continue to be exclusively breastfed for six months show deficits in weight or length gain, although larger sample sizes would be required to rule out modest differences in risk of undernutrition. In developing-country settings where newborn iron stores may be suboptimal, the evidence suggests that exclusive breastfeeding without iron supplementation through six months may compromise hematologic status. Based on the Belarusian study, six months of exclusive breastfeeding confers no benefit (versus three months of exclusive breastfeeding followed by continued partial breastfeeding through six months) on height, weight, body mass index, dental caries, cognitive ability, or behaviour at 6.5 years of age. Based on studies from Belarus, Iran, and Nigeria, however, infants who continue exclusive breastfeeding for six months or more appear to have a significantly reduced risk of gastrointestinal and (in the Iranian and Nigerian studies) respiratory infection. No significant reduction in risk of atopic eczema, asthma, or other atopic outcomes has been demonstrated in studies from Finland, Australia, and Belarus. Data from the two Honduran trials and from observational studies from Bangladesh and Senegal suggest that exclusive breastfeeding through six months is associated with delayed resumption of menses and, in the Honduran trials, more rapid postpartum weight loss in the mother.
Infants who are exclusively breastfed for six months experience less morbidity from gastrointestinal infection than those who are partially breastfed as of three or four months, and no deficits have been demonstrated in growth among infants from either developing or developed countries who are exclusively breastfed for six months or longer. Moreover, the mothers of such infants have more prolonged lactational amenorrhea. Although infants should still be managed individually so that insufficient growth or other adverse outcomes are not ignored and appropriate interventions are provided, the available evidence demonstrates no apparent risks in recommending, as a general policy, exclusive breastfeeding for the first six months of life in both developing and developed-country settings.
Objective Because the diagnosis of postpartum hemorrhage (PPH) depends on the accoucheur's subjective estimate of blood loss and varies according to mode of delivery, we examined temporal trends in ...severe PPH, defined as PPH plus receipt of a blood transfusion, hysterectomy, and/or surgical repair of the uterus. Study Design We analyzed 8.5 million hospital deliveries in the US Nationwide Inpatient Sample from 1999 to 2008 for temporal trends in, and risk factors for, severe PPH, based on International Classification of Diseases, 9th revision, clinical modification diagnosis and procedure codes. Sequential logistic regression models that account for the stratified random sampling design were used to assess the extent to which changes in risk factors explain the trend in severe PPH. Results Of the total 8,571,209 deliveries, 25,906 (3.0 per 1000) were complicated by severe PPH. The rate rose from 1.9 to 4.2 per 1000 from 1999 to 2008 ( P for yearly trend < .0001), with increases in severe atonic and nonatonic PPH, due especially to PPH with transfusion, but also PPH with hysterectomy. Significant risk factors included maternal age ≥35 years (adjusted odds ratio aOR, 1.5; 95% confidence interval CI, 1.5–1.6), multiple pregnancy (aOR, 2.8; 95% CI, 2.6–3.0), fibroids (aOR, 2.0; 95% CI, 1.8–2.2), preeclampsia (aOR, 3.1; 95% CI, 2.9–3.3), amnionitis (aOR, 2.9; 95% CI, 2.5–3.4), placenta previa or abruption (aOR, 7.0; 95% CI, 6.6–7.3), cervical laceration (aOR, 94.0; 95% CI, 87.3–101.2), uterine rupture (aOR, 11.6; 95% CI, 9.7–13.8), instrumental vaginal delivery (aOR, 1.5; 95% CI, 1.4–1.6), and cesarean delivery (aOR, 1.4; 95% CI, 1.3–1.5). Changes in risk factors, however, accounted for only 5.6% of the increase in severe PPH. Conclusion A doubling in incidence of severe PPH over 10 years was not explained by contemporaneous changes in studied risk factors.
To explore international differences in the classification of births at extremely low gestation and the subsequent impact on the calculation of survival rates.
We used national data on births at 22 ...to 25 weeks' gestation from the United States (2014;
= 11 144), Canada (2009-2014;
= 5668), the United Kingdom (2014-2015;
= 2992), Norway (2010-2014;
= 409), Finland (2010-2015;
= 348), Sweden (2011-2014;
= 489), and Japan (2014-2015;
= 2288) to compare neonatal survival rates using different denominators: all births, births alive at the onset of labor, live births, live births surviving to 1 hour, and live births surviving to 24 hours.
For births at 22 weeks' gestation, neonatal survival rates for which we used live births as the denominator varied from 3.7% to 56.7% among the 7 countries. This variation decreased when the denominator was changed to include stillbirths (ie, all births 1.8%-22.3% and fetuses alive at the onset of labor 3.7%-38.2%) or exclude early deaths and limited to births surviving at least 12 hours (50.0%-77.8%). Similar trends were seen for infants born at 23 weeks' gestation. Variation diminished considerably at 24 and 25 weeks' gestation.
International variation in neonatal survival rates at 22 to 23 weeks' gestation diminished considerably when including stillbirths in the denominator, revealing the variation arises in part from differences in the proportion of births reported as live births, which itself is closely connected to the provision of active care.
One of the United Nations' Millennium Development Goals of 2000 was to reduce maternal mortality by 75% in 15 y; however, this challenge was not met by many industrialized countries. As average ...maternal age continues to rise in these countries, associated potentially life-threatening severe maternal morbidity has been understudied. Our primary objective was to examine the associations between maternal age and severe maternal morbidities. The secondary objective was to compare these associations with those for adverse fetal/infant outcomes.
This was a population-based retrospective cohort study, including all singleton births to women residing in Washington State, US, 1 January 2003-31 December 2013 (n = 828,269). We compared age-specific rates of maternal mortality/severe morbidity (e.g., obstetric shock) and adverse fetal/infant outcomes (e.g., perinatal death). Logistic regression was used to adjust for parity, body mass index, assisted conception, and other potential confounders. We compared crude odds ratios (ORs) and adjusted ORs (AORs) and risk differences and their 95% CIs. Severe maternal morbidity was significantly higher among teenage mothers than among those 25-29 y (crude OR = 1.5, 95% CI 1.5-1.6) and increased exponentially with maternal age over 39 y, from OR = 1.2 (95% CI 1.2-1.3) among women aged 35-39 y to OR = 5.4 (95% CI 2.4-12.5) among women aged ≥50 y. The elevated risk of severe morbidity among teen mothers disappeared after adjustment for confounders, except for maternal sepsis (AOR = 1.2, 95% CI 1.1-1.4). Adjusted rates of severe morbidity remained increased among mothers ≥35 y, namely, the rates of amniotic fluid embolism (AOR = 8.0, 95% CI 2.7-23.7) and obstetric shock (AOR = 2.9, 95% CI 1.3-6.6) among mothers ≥40 y, and renal failure (AOR = 15.9, 95% CI 4.8-52.0), complications of obstetric interventions (AOR = 4.7, 95% CI 2.3-9.5), and intensive care unit (ICU) admission (AOR = 4.8, 95% CI 2.0-11.9) among those 45-49 y. The adjusted risk difference in severe maternal morbidity compared to mothers 25-29 y was 0.9% (95% CI 0.7%-1.2%) for mothers 40-44 y, 1.6% (95% CI 0.7%-2.8%) for mothers 45-49 y, and 6.4% for mothers ≥50 y (95% CI 1.7%-18.2%). Similar associations were observed for fetal and infant outcomes; neonatal mortality was elevated in teen mothers (AOR = 1.5, 95% CI 1.2-1.7), while mothers over 29 y had higher risk of stillbirth. The rate of severe maternal morbidity among women over 49 y was higher than the rate of mortality/serious morbidity of their offspring. Despite the large sample size, statistical power was insufficient to examine the association between maternal age and maternal death or very rare severe morbidities.
Maternal age-specific incidence of severe morbidity varied by outcome. Older women (≥40 y) had significantly elevated rates of some of the most severe, potentially life-threatening morbidities, including renal failure, shock, acute cardiac morbidity, serious complications of obstetric interventions, and ICU admission. These results should improve counselling to women who contemplate delaying childbirth until their forties and provide useful information to their health care providers. This information is also useful for preventive strategies to lower maternal mortality and severe maternal morbidity in developed countries.
In a Perspective, Sarka Lisonkova and Michael Kramer discuss the accompanying study by Kathryn Fitzpatrick and co-authors on management of amniotic fluid embolism.
Some breastfed infants with atopic eczema benefit from elimination of cow milk, egg, or other antigens from their mother's diet. Maternal dietary antigens are also known to cross the placenta.
To ...assess the effects of prescribing an antigen avoidance diet during pregnancy or lactation, or both, on maternal and infant nutrition and on the prevention or treatment of atopic disease in the child.
We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (6 July 2012).
All randomized or quasi-randomized comparisons of maternal dietary antigen avoidance prescribed to pregnant or lactating women. We excluded trials of multimodal interventions that included manipulation of the infant's diet other than breast milk or of non-dietary aspects of the infant's environment.
We extracted data from published reports, supplemented by additional information received from the trialists we contacted.
The evidence from five trials, involving 952 participants, does not suggest a protective effect of maternal dietary antigen avoidance during pregnancy on the incidence of atopic eczema during the first 18 months of life. Data on allergic rhinitis or conjunctivitis, or both, and urticaria are limited to a single trial each and are insufficient to draw meaningful inferences. Longer-term atopic outcomes have not been reported. The restricted diet during pregnancy was associated with a slightly but statistically significantly lower mean gestational weight gain, a non-significantly higher risk of preterm birth, and a non-significant reduction in mean birthweight.The evidence from two trials, involving 523 participants, did not observe a significant protective effect of maternal antigen avoidance during lactation on the incidence of atopic eczema during the first 18 months or on positive skin-prick tests to cow milk, egg, or peanut antigen at one, two, or seven years.One crossover trial involving 17 lactating mothers of infants with established atopic eczema found that maternal dietary antigen avoidance was associated with a non-significant reduction in eczema severity.
Prescription of an antigen avoidance diet to a high-risk woman during pregnancy is unlikely to reduce substantially her child's risk of atopic diseases, and such a diet may adversely affect maternal or fetal nutrition, or both. Prescription of an antigen avoidance diet to a high-risk woman during lactation may reduce her child's risk of developing atopic eczema, but better trials are needed.Dietary antigen avoidance by lactating mothers of infants with atopic eczema may reduce the severity of the eczema, but larger trials are needed.
Racial disparities in health are well-documented and represent a significant public health concern in the US. Racism-related factors contribute to poorer health and higher mortality rates among ...Blacks compared to other racial groups. However, methods to measure racism and monitor its associations with health at the population-level have remained elusive. In this study, we investigated the utility of a previously developed Internet search-based proxy of area racism as a predictor of Black mortality rates. Area racism was the proportion of Google searches containing the "N-word" in 196 designated market areas (DMAs). Negative binomial regression models were specified taking into account individual age, sex, year of death, and Census region and adjusted to the 2000 US standard population to examine the association between area racism and Black mortality rates, which were derived from death certificates and mid-year population counts collated by the National Center for Health Statistics (2004-2009). DMAs characterized by a one standard deviation greater level of area racism were associated with an 8.2% increase in the all-cause Black mortality rate, equivalent to over 30,000 deaths annually. The magnitude of this effect was attenuated to 5.7% after adjustment for DMA-level demographic and Black socioeconomic covariates. A model controlling for the White mortality rate was used to further adjust for unmeasured confounders that influence mortality overall in a geographic area, and to examine Black-White disparities in the mortality rate. Area racism remained significantly associated with the all-cause Black mortality rate (mortality rate ratio = 1.036; 95% confidence interval = 1.015, 1.057; p = 0.001). Models further examining cause-specific Black mortality rates revealed significant associations with heart disease, cancer, and stroke. These findings are congruent with studies documenting the deleterious impact of racism on health among Blacks. Our study contributes to evidence that racism shapes patterns in mortality and generates racial disparities in health.
Abstract
Natal kicks and spins are characteristic properties of neutron stars (NSs) and black holes (BHs). Both offer valuable clues to dynamical processes during stellar core collapse and explosion. ...Moreover, they influence the evolution of stellar multiple systems and the gravitational-wave signals from their inspiral and merger. Observational evidence of a possibly generic spin-kick alignment has been interpreted as an indication that NS spins are either induced with the NS kicks or inherited from the progenitor rotation, which thus might play a dynamically important role during stellar collapse. Current three-dimensional supernova simulations suggest that NS kicks are transferred in the first seconds of the explosion, mainly by anisotropic mass ejection and, on a secondary level, anisotropic neutrino emission. By contrast, the NS spins are only determined minutes to hours later by the angular momentum associated with the fallback of matter that does not become gravitationally unbound in the supernova. Here, we propose a novel scenario to explain spin-kick alignment as a consequence of tangential vortex flows in the fallback matter that is accreted mostly from the direction of the NS’s motion. For this effect the initial NS kick is crucial, because it produces a growing offset of the NS away from the explosion center, thus promoting one-sided accretion. In this new scenario conclusions based on traditional concepts are reversed. For example, pre-kick NS spins are not required, and rapid progenitor core rotation can hamper spin-kick alignment. We also discuss implications for natal BH kicks and the possibility of tossing the BH’s spin axis during its formation.
That the places we live, work, and play matter for individual and population health across the human life course is both incredibly consequential and relatively uncontested in modern social ...epidemiology. In a keynote address at the 2019 GEOMED meeting, Ana Diez Roux-an early proponent of applying the sociological neighborhood effects framework to the descriptive and explanatory tasks of epidemiology-summarized four evolving stages of conceptual thinking in the place and population health scholarship since the 1990s1: (1) places are context for health, (2) places are causes ofhealth, (3) places are effect modifiers or reinforcers of individual or social health-relevant processes, and (4) places are components of complex systems that dynamically produce and distribute experiences, exposures, and opportunities, which give rise to socially structured patterns of population health.This progression toward increasingly complex and dynamic thinking about relations between places and population health is evident in the growth and evolution of research examining how residential locale affects reproductive and perinatal health outcomes. In this issue of AJPH, Krieger et al. (p. 1046) make an important contribution to this body of research by asking whether the historical process of mortgage redlining in specific New York City neighborhoods predicts the risk for preterm birth among women residing in those neighborhoods and delivering liveborn, singleton infants in 2013 through 2017. By contrast to much of the neighborhood effects research focusing on temporally proximate or contemporary exposures and outcomes, Krieger et al. use the 1938 maps created by the federally sponsored Home Owners Loan Corporation (HOLC) of investment "risk" guiding mortgage lenders as predictive exposures. These maps-where "hazardous" neighborhoods are outlined in red giving rise to the term "redlining"-codified the racialized government policy of public investment in White and middle-class communities and disinvestment in neighborhoods with Black, Puerto Rican, or foreign-born residents. Anyone doubting the explicit racialized motivation underpinning the map categories should peruse the comments and notes abstracted from the original maps as summarized in Table B of Krieger et al. (available as a supplement to the online version of their article at http://www.ajph.org).The inclusion of 1938 mortgage lending policy is not evoked in this study as a direct experience or exposure for women who are not giving birth until the second decade of the 21st century. Instead, Krieger et al. posit that this historical fact (the HOLC maps and their role in guiding mortgage lending) stands as an influential node in the spatiotemporally dynamic urban ecology of populations and places. The authors find modest empirical evidence that the 1938 HOLC categories predicted contemporary risk for preterm birth, independent of important individual demographic, socioeconomic, and health risk factors. These findings have implications for how we interpret cross-sectional analysis of geographic variation in health, how we conceive of the social causes of health and health disparities, and consequently what kinds of public health actions might plausibly disrupt the status quo ofhealth inequity.
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