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1.
J Nutr ; 154(6): 1917-1926, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38621624

RESUMEN

BACKGROUND: Data regarding effects of small-quantity-lipid-based nutrient supplements (SQ-LNS) on maternal serum zinc concentrations (SZC) in pregnancy and lactation are limited. OBJECTIVES: The objectives of this study were to evaluate the effect of preconception compared with prenatal zinc supplementation (compared with control) on maternal SZC and hypozincemia during pregnancy and early lactation in women in low-resource settings, and assess associations with birth anthropometry. METHODS: From ∼100 women/arm at each of 3 sites (Guatemala, India, and Pakistan) of the Women First Preconception Maternal Nutrition trial, we compared SZC at 12- and 34-wk gestation (n = 651 and 838, respectively) and 3-mo postpartum (n = 742) in women randomly assigned to daily SQ-LNS containing 15 mg zinc from ≥3 mo before conception (preconception, arm 1), from ∼12 wk gestation through delivery (early pregnancy, arm 2) or not at all (control, arm 3). Birth anthropometry was examined for newborns with ultrasound-determined gestational age. Statistical analyses were performed separately for each time point. RESULTS: At 12-wk gestation and 3-mo postpartum, no statistical differences in mean SZC were observed among arms. At 34-wk, mean SZC for arms 1 and 2 were significantly higher than for arm 3 (50.3, 50.8, 47.8 µg/dL, respectively; P = 0.005). Results were not impacted by correction for inflammation or albumin concentrations. Prevalence of hypozincemia at 12-wk (<56 µg/dL) was 23% in Guatemala, 26% in India, and 65% in Pakistan; at 34 wk (<50 µg/dL), 36% in Guatemala, 48% in India, and 74% in Pakistan; and at 3-mo postpartum (<66 µg/dL) 79% in Guatemala, 91% in India, and 92% in Pakistan. Maternal hypozincemia at 34-wk was associated with lower birth length-for-age Z-scores (all sites P = 0.013, Pakistan P = 0.008) and weight-for-age Z-scores (all sites P = 0.017, Pakistan P = 0.022). CONCLUSIONS: Despite daily zinc supplementation for ≥7 mo, high rates of maternal hypozincemia were observed. The association of hypozincemia with impaired fetal growth suggests widespread zinc deficiency in these settings. This trial is registered at clinicaltrials.gov as #NCT01883193.


Asunto(s)
Suplementos Dietéticos , Lactancia , Fenómenos Fisiologicos Nutricionales Maternos , Zinc , Humanos , Femenino , Embarazo , Zinc/administración & dosificación , Zinc/sangre , Adulto , Recién Nacido , Prevalencia , Adulto Joven , Complicaciones del Embarazo , India , Estado Nutricional , Atención Preconceptiva
2.
Matern Child Nutr ; 20(1): e13572, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-37817452

RESUMEN

This research describes the proportion of children in four low- and middle-income countries with adequate dietary practices at 6, 12, 18 and 24 months of age and how these practices changed over time using the World Health Organisation and UNICEF's infant young child feeding (IYCF) indicators. The associations between the IYCF indicators and anthropometric z-scores from 6 to 24 months, and between the IYCF indicators and the family care indicators (FCIs) at 24 months are described. This was a longitudinal study of offspring from participants in the Women First Preconception Maternal Nutrition Trial conducted in Sud-Ubangi, Democratic Republic of Congo; Chimaltenango, Guatemala; Belagavi, North Karnataka, India; and Thatta, Sindh Province, Pakistan. The frequency of the minimum dietary diversity (MDD), minimum meal frequency (MMF), and minimum adequate diet (MAD) increased between 6 and 24 months, but even at 24 months MAD remained below 50% at all sites. MDD (ß = 0.12; 95% CI = 0.04-0.22) and MMF (ß = 0.10; 95% CI = 0.03-0.17) were positively associated with length-for-age z-score at 24 months. All IYCF indicators were positively associated with mean total FCI score: MDD (proportion ratio [PR] = 1.04; 95% CI = 1.02-1.07), MMF (PR = 1.02; 95% CI = 1.01-1.04), MAD (PR = 1.05; 95% CI = 1.02-1.08). Although there are multiple barriers to young children having an adequate diet, our results support a positive association between familial interactions and improved IYCF feeding practices.


Asunto(s)
Lactancia Materna , Fenómenos Fisiológicos Nutricionales del Lactante , Lactante , Niño , Humanos , Femenino , Preescolar , Estudios Longitudinales , India , Dieta , Conducta Alimentaria
3.
BJOG ; 130(4): 366-376, 2023 03.
Artículo en Inglés | MEDLINE | ID: mdl-36504437

RESUMEN

OBJECTIVES: To determine COVID-19 antibody positivity rates over time and relationships to pregnancy outcomes in low- and middle-income countries (LMICs). DESIGN: With COVID-19 antibody positivity at delivery as the exposure, we performed a prospective, observational cohort study in seven LMICs during the early COVID-19 pandemic. SETTING: The study was conducted among women in the Global Network for Women's and Children's Health's Maternal and Newborn Health Registry (MNHR), a prospective, population-based study in Kenya, Zambia, the Democratic Republic of the Congo (DRC), Bangladesh, Pakistan, India (two sites), and Guatemala. POPULATION: Pregnant women enrolled in an ongoing pregnancy registry at study sites. METHODS: From October 2020 to October 2021, standardised COVID-19 antibody testing was performed at delivery among women enrolled in MNHR. Trained staff masked to COVID-19 status obtained pregnancy outcomes, which were then compared with COVID-19 antibody results. MAIN OUTCOME MEASURES: Antibody status, stillbirth, neonatal mortality, maternal mortality and morbidity. RESULTS: At delivery, 26.0% of women were COVID-19 antibody positive. Positivity increased over the four time periods across all sites: 13.8%, 15.4%, 21.0% and 40.9%. In the final period, positivity rates were: DRC 27.0%, Kenya 33.1%, Pakistan 32.8%, Guatemala 37.0%, Zambia 37.8%, Bangladesh 47.2%, Nagpur, India 57.4% and Belagavi, India 62.4%. Adjusting for site and maternal characteristics, stillbirth, neonatal mortality, low birthweight and preterm birth were not significantly associated with COVID-19. The adjusted relative risk (aRR) for stillbirth was 1.27 (95% CI 0.95-1.69). Postpartum haemorrhage was associated with antibody positivity (aRR 1.44; 95% CI 1.01-2.07). CONCLUSIONS: In pregnant populations in LMICs, COVID-19 antibody positivity has increased. However, most adverse pregnancy outcomes were not significantly associated with antibody positivity.


Asunto(s)
COVID-19 , Nacimiento Prematuro , Niño , Embarazo , Femenino , Recién Nacido , Humanos , Resultado del Embarazo/epidemiología , Mortinato/epidemiología , Salud Infantil , Países en Desarrollo , Estudios Prospectivos , Prueba de COVID-19 , Pandemias , Nacimiento Prematuro/epidemiología , COVID-19/epidemiología , Salud de la Mujer , Mortalidad Infantil
4.
Reprod Health ; 20(1): 167, 2023 Nov 13.
Artículo en Inglés | MEDLINE | ID: mdl-37957689

RESUMEN

BACKGROUND: Many low- and-middle-income countries are disproportionately burdened by cervical cancer, resulting in high morbidity and mortality. HPV-DNA testing coupled with treatment with thermal ablation is a recommended screening and precancer treatment strategy, but not enough is known about how this can be effectively implemented in the context of integrated services. The (Scale Up Cervical Cancer Elimination by Secondary prevention Strategy, (SUCCESS) project is conducting a study to understand this approach, integrated into existing women's health services in Burkina Faso, Cote d'Ivoire, Guatemala, and the Philippines (2020-2024). METHODS: A hybrid effectiveness-implementation type III mixed-methods observational study design is used to assess feasibility, acceptability, and costs of integrated service delivery in 10 sites per country, selected considering urban/rural location, facility level, onsite/offsite laboratories, and health services type. In each country, a sample size of 2227 women aged 25-49 years will be enrolled with about 20% being women living with HIV. The primary outcome is proportion of HPV positive women completing precancer treatment, if eligible, within three months of screening. Data collection and analysis includes; facility and client exit surveys, key informant and client interviews, registries and project records extractions, and costing data analysis. Analysis includes descriptive statistics, context description, thematic analysis, and document analysis. Quantitative analyses will be stratified by participant's HIV status. DISCUSSION: Recruitment of study participants started in April 2022 (Burkina Faso and Côte d'Ivoire) and August 2022 (Guatemala and the Philippines). Enrolment targets for women screened, client exit, in-depth and key informant interviews conducted were reached in Burkina Faso and Cote d'Ivoire in November 2022. Guatemala and Philippines are expected to complete enrolment by June 2023. Follow-up of study Participants 12-months post-treatment is ongoing and is expected to be completed for all countries by August 2024. In LMICs, integrating cervical cancer secondary prevention services into other health services will likely require specific rather than incidental recruitment of women for screening. Reconfiguration of laboratory infrastructure and planning for sample management must be made well in advance to meet induced demand for screening. Trail Registration ClinicalTrials.Gov ID: NCT05133661 (24/11/2021).


Asunto(s)
Infecciones por VIH , Infecciones por Papillomavirus , Neoplasias del Cuello Uterino , Humanos , Femenino , Masculino , Côte d'Ivoire/epidemiología , Burkina Faso/epidemiología , Neoplasias del Cuello Uterino/diagnóstico , Neoplasias del Cuello Uterino/prevención & control , Guatemala/epidemiología , Filipinas/epidemiología , Infecciones por Papillomavirus/diagnóstico , Infecciones por Papillomavirus/prevención & control , Infecciones por VIH/prevención & control , Estudios Observacionales como Asunto
5.
BJOG ; 129(12): 2002-2009, 2022 11.
Artículo en Inglés | MEDLINE | ID: mdl-35596701

RESUMEN

OBJECTIVES: We sought to determine the knowledge, attitudes and practices of pregnant women regarding COVID-19 vaccination in pregnancy in seven low- and middle-income countries (LMIC). DESIGN: Prospective, observational, population-based study. SETTINGS: Study areas in seven LMICs: Bangladesh, India, Pakistan, Guatemala, Democratic Republic of the Congo (DRC), Kenya and Zambia. POPULATION: Pregnant women in an ongoing registry. METHODS: COVID-19 vaccine questionnaires were administered to pregnant women in the Global Network's Maternal Newborn Health Registry from February 2021 through November 2021 in face-to-face interviews. MAIN OUTCOME MEASURES: Knowledge, attitude and practice regarding vaccination during pregnancy; vaccination status. RESULTS: No women were vaccinated except for small proportions in India (12.9%) and Guatemala (5.5%). Overall, nearly half the women believed the COVID-19 vaccine is very/somewhat effective and a similar proportion believed that the COVID-19 vaccine is safe for pregnant women. With availability of vaccines, about 56.7% said they would get the vaccine and a 34.8% would refuse. Of those who would not get vaccinated, safety, fear of adverse effects, and lack of trust predicted vaccine refusal. Those with lower educational status were less willing to be vaccinated. Family members and health professionals were the most trusted source of information for vaccination. CONCLUSIONS: This COVID-19 vaccine survey in seven LMICs found that knowledge about the effectiveness and safety of the vaccine was generally low but varied. Concerns about vaccine safety and effectiveness among pregnant women is an important target for educational efforts to increase vaccination rates.


Asunto(s)
COVID-19 , Vacunas , COVID-19/epidemiología , COVID-19/prevención & control , Vacunas contra la COVID-19/uso terapéutico , Niño , Salud Infantil , Países en Desarrollo , Femenino , Conocimientos, Actitudes y Práctica en Salud , Humanos , Recién Nacido , Embarazo , Mujeres Embarazadas , Estudios Prospectivos , Vacunación
6.
BJOG ; 129(8): 1298-1307, 2022 07.
Artículo en Inglés | MEDLINE | ID: mdl-35377514

RESUMEN

OBJECTIVE: To assess, on a population basis, the medical care for pregnant women in specific geographic regions of six countries before and during the first year of the coronavirus disease 2019 (COVID-19) pandemic in relationship to pregnancy outcomes. DESIGN: Prospective, population-based study. SETTING: Communities in Kenya, Zambia, the Democratic Republic of the Congo, Pakistan, India and Guatemala. POPULATION: Pregnant women enrolled in the Global Network for Women's and Children's Health's Maternal and Newborn Health Registry. METHODS: Pregnancy/delivery care services and pregnancy outcomes in the pre-COVID-19 time-period (March 2019-February 2020) were compared with the COVID-19 time-period (March 2020-February 2021). MAIN OUTCOME MEASURES: Stillbirth, neonatal mortality, preterm birth, low birthweight and maternal mortality. RESULTS: Across all sites, a small but statistically significant increase in home births occurred between the pre-COVID-19 and COVID-19 periods (18.9% versus 20.3%, adjusted relative risk [aRR] 1.12, 95% CI 1.05-1.19). A small but significant decrease in the mean number of antenatal care visits (from 4.1 to 4.0, p = <0.0001) was seen during the COVID-19 period. Of outcomes evaluated, overall, a small but significant decrease in low-birthweight infants in the COVID-19 period occurred (15.7% versus 14.6%, aRR 0.94, 95% CI 0.89-0.99), but we did not observe any significant differences in other outcomes. There was no change observed in maternal mortality or antenatal haemorrhage overall or at any of the sites. CONCLUSIONS: Small but significant increases in home births and decreases in the antenatal care services were observed during the initial COVID-19 period; however, there was not an increase in the stillbirth, neonatal mortality, maternal mortality, low birthweight, or preterm birth rates during the COVID-19 period compared with the previous year. Further research should help to elucidate the relationship between access to and use of pregnancy-related medical services and birth outcomes over an extended period.


Asunto(s)
COVID-19 , Nacimiento Prematuro , Peso al Nacer , COVID-19/epidemiología , Niño , Salud Infantil , Atención a la Salud , Países en Desarrollo , Femenino , Humanos , Lactante , Recién Nacido , Pandemias , Embarazo , Resultado del Embarazo/epidemiología , Nacimiento Prematuro/epidemiología , Estudios Prospectivos , Sistema de Registros , Mortinato/epidemiología , Salud de la Mujer
7.
Lancet ; 395(10220): 285-293, 2020 01 25.
Artículo en Inglés | MEDLINE | ID: mdl-31982074

RESUMEN

BACKGROUND: Preterm birth remains a common cause of neonatal mortality, with a disproportionately high burden in low-income and middle-income countries. Meta-analyses of low-dose aspirin to prevent pre-eclampsia suggest that the incidence of preterm birth might also be decreased, particularly if initiated before 16 weeks of gestation. METHODS: ASPIRIN was a randomised, multicountry, double-masked, placebo-controlled trial of low-dose aspirin (81 mg daily) initiated between 6 weeks and 0 days of pregnancy, and 13 weeks and 6 days of pregnancy, in nulliparous women with an ultrasound confirming gestational age and a singleton viable pregnancy. Participants were enrolled at seven community sites in six countries (two sites in India and one site each in the Democratic Republic of the Congo, Guatemala, Kenya, Pakistan, and Zambia). Participants were randomly assigned (1:1, stratified by site) to receive aspirin or placebo tablets of identical appearance, via a sequence generated centrally by the data coordinating centre at Research Triangle Institute International (Research Triangle Park, NC, USA). Treatment was masked to research staff, health providers, and patients, and continued until 36 weeks and 7 days of gestation or delivery. The primary outcome of incidence of preterm birth, defined as the number of deliveries before 37 weeks' gestational age, was analysed in randomly assigned women with pregnancy outcomes at or after 20 weeks, according to a modified intention-to-treat (mITT) protocol. Analyses of our binary primary outcome involved a Cochran-Mantel-Haenszel test stratified by site, and generalised linear models to obtain relative risk (RR) estimates and associated confidence intervals. Serious adverse events were assessed in all women who received at least one dose of drug or placebo. This study is registered with ClinicalTrials.gov, NCT02409680, and the Clinical Trial Registry-India, CTRI/2016/05/006970. FINDINGS: From March 23, 2016 to June 30, 2018, 14 361 women were screened for inclusion and 11 976 women aged 14-40 years were randomly assigned to receive low-dose aspirin (5990 women) or placebo (5986 women). 5780 women in the aspirin group and 5764 in the placebo group were evaluable for the primary outcome. Preterm birth before 37 weeks occurred in 668 (11·6%) of the women who took aspirin and 754 (13·1%) of those who took placebo (RR 0·89 [95% CI 0·81 to 0·98], p=0·012). In women taking aspirin, we also observed significant reductions in perinatal mortality (0·86 [0·73-1·00], p=0·048), fetal loss (infant death after 16 weeks' gestation and before 7 days post partum; 0·86 [0·74-1·00], p=0·039), early preterm delivery (<34 weeks; 0·75 [0·61-0·93], p=0·039), and the incidence of women who delivered before 34 weeks with hypertensive disorders of pregnancy (0·38 [0·17-0·85], p=0·015). Other adverse maternal and neonatal events were similar between the two groups. INTERPRETATION: In populations of nulliparous women with singleton pregnancies from low-income and middle-income countries, low-dose aspirin initiated between 6 weeks and 0 days of gestation and 13 weeks and 6 days of gestation resulted in a reduced incidence of preterm delivery before 37 weeks, and reduced perinatal mortality. FUNDING: Eunice Kennedy Shriver National Institute of Child Health and Human Development.


Asunto(s)
Aspirina/administración & dosificación , Preeclampsia/epidemiología , Nacimiento Prematuro/epidemiología , Adolescente , Adulto , Aspirina/efectos adversos , Presión Sanguínea , Parto Obstétrico/estadística & datos numéricos , Países en Desarrollo , Método Doble Ciego , Femenino , Humanos , Preeclampsia/prevención & control , Embarazo , Resultado del Embarazo/epidemiología , Nacimiento Prematuro/prevención & control , Adulto Joven
8.
J Pediatr ; 229: 199-206.e4, 2021 02.
Artículo en Inglés | MEDLINE | ID: mdl-32956698

RESUMEN

OBJECTIVE: To evaluate whether the fetal linear growth effects of maternal nutrition supplementation would be maintained through 6 months postnatal age. STUDY DESIGN: The Women First trial was a multicountry, individually randomized clinical trial that compared the impact of maternal nutrition supplementation initiated preconception (Arm 1) vs at ∼11 weeks of gestation (Arm 2), vs no supplement (Arm 3); the intervention was discontinued at delivery. Trial sites were in Democratic Republic of Congo, Guatemala, India, and Pakistan. Analysis includes 2421 infants born to 2408 randomized women. Primary outcome was the trajectory of length-for-age z scores (LAZ) by arm, based on assessments at birth and 1, 3, and 6 months. We fitted longitudinal models on growth from birth to 6 months using generalized estimating equations; maternal intervention effects were evaluated, adjusting for site and baseline maternal covariates. RESULTS: Linear growth for Arms 1 and 2 was statistically greater than for Arm 3 in 3 of the 4 countries, with average pairwise mean differences in LAZ of 0.25 (95% CI 0.15-0.35; P < .001) and 0.19 (95% CI 0.09-0.28; P < .001), respectively. Compared with Arm 3, average overall adjusted relative risks (95% CI) for stunting (LAZ <-2) were lower for Arms 1 and 2: 0.76 (0.66-0.87; P < .001) and 0.77 (0.67-0.88; P < .001), respectively. CONCLUSIONS: Improved linear growth in early infancy observed for the 2 intervention arms supports the critical importance of maternal nutrition before conception and in the early phase of gestation. TRIAL REGISTRATION: ClinicalTrials.gov: NCT01883193.


Asunto(s)
Suplementos Dietéticos , Desarrollo Fetal , Crecimiento , Fenómenos Fisiologicos Nutricionales Maternos , Atención Preconceptiva , Femenino , Humanos , Lactante , Recién Nacido , Adulto Joven
9.
J Nutr ; 151(3): 556-569, 2021 03 11.
Artículo en Inglés | MEDLINE | ID: mdl-33382407

RESUMEN

BACKGROUND: Preconceptional maternal small-quantity lipid-based nutrient supplementation (SQLNS) improved intrauterine linear growth in low-resource countries as demonstrated by the Women First Preconception Maternal Nutrition Trial (WF). Fetal growth is dependent on nutrient availability and regulated by insulin-like growth factor 1 (IGF-1) through changes in placental transfer capacity, mediated by the mechanistic target of rapamycin (mTOR) pathway. OBJECTIVES: Our objective was to evaluate the role of placental mTOR and IGF-1 signaling on fetal growth in women from 2 low-resource countries with high rates of stunting after they received preconceptional SQLNS. METHODS: We studied 48 women from preconception through delivery who were from Guatemala and Pakistan and received SQLNS or not, as part of the WF study. Placental samples were obtained at delivery (control, n = 24; SQLNS, n = 24). Placental protein or mRNA expression of eukaryotic translation initiation factor binding protein-1 (4E-BP1), ribosomal protein S6 (rpS6), AMP-activated protein kinase α (AMPKA), IGF-1, insulin-like growth factor receptor (IGF-1R), and pregnancy associated plasma protein (PAPP)-A, and DNA methylation of the IGF1 promoter were determined. Maternal serum IGF-1, insulin-like growth factor binding protein (IGFBP)-3, IGFBP-4, IGFBP-5, PAPP-A, PAPP-A2, and zinc were measured. RESULTS: Mean ± SEM maternal prepregnancy BMI differed between participants in Guatemala (26.5 ± 1.3) and Pakistan (19.8 ± 0.7) (P < 0.001). In Pakistani participants, SQLNS increased the placental rpS6(T37/46):rpS6 ratio (1.5-fold) and decreased the AMPKA(T172):AMPKA ratio. Placental IGF1 mRNA expression was positively correlated with birth length and birth weight z-scores. Placental PAPP-A (30-fold) and maternal serum zinc (1.2-fold) increased with SQLNS. In Guatemalan participants SQLNS did not influence placental mTOR signaling. Placental IGF-1R protein expression was positively associated with birth length and birth weight z-scores. SQLNS increased placental PAPP-A (40-fold) and maternal serum IGFBP-4 (1.6-fold). CONCLUSIONS: In Pakistani pregnant women with poor nutritional status, preconceptional SQLNS activated placental mTOR and IGF-1 signaling and was associated with improved fetal growth. In contrast, in Guatemalan women SQLNS did not activate placental nutrient-sensing pathways. In populations experiencing childhood stunting, preconceptional SQLNS improves placental function and fetal growth only in the context of poor maternal nutrition. This trial was registered at clinicaltrials.gov as NCT01883193.


Asunto(s)
Suplementos Dietéticos , Factor I del Crecimiento Similar a la Insulina/metabolismo , Lípidos/química , Placenta/metabolismo , Atención Preconceptiva , Serina-Treonina Quinasas TOR/metabolismo , Países en Desarrollo , Femenino , Regulación de la Expresión Génica/efectos de los fármacos , Humanos , Factor I del Crecimiento Similar a la Insulina/genética , Placenta/efectos de los fármacos , Embarazo , Serina-Treonina Quinasas TOR/genética
10.
BMC Pregnancy Childbirth ; 21(1): 516, 2021 Jul 20.
Artículo en Inglés | MEDLINE | ID: mdl-34284728

RESUMEN

BACKGROUND: The objective of this analysis was to observe whether maternal and perinatal/neonatal outcomes of birth vary by timing of repeat cesarean among women with a history of one prior cesarean birth in a Guatemalan cohort. METHODS: This secondary analysis was conducted using data from a prospective study conducted in communities in Chimaltenango, Guatemala through the Global Network for Women's and Children's Health Research. RESULTS: Between January 2017 and April 2020, 26,465 women delivered; 3,143 (11.9%) of those women had a singleton gestation and a history of prior cesarean delivery. 2,210 (79.9%) women with a history of prior cesarean birth had data available on mode of delivery and gave birth by repeat cesarean; 1312 (59.4%) were pre-labor cesareans while 896 (40.5%) were intrapartum cesarean births. Risk factors associated with an increased risk of intrapartum cesarean birth included hospital delivery as compared to "other" location (ARR 1.6 [1.2,2.1]) and dysfunctional labor (ARR 1.6 [1.4,1.9]). Variables associated with a reduced risk of intrapartum cesarean birth were hypertensive disease (ARR 0.7 [0.6,0.9]), schooling (ARR 0.9 [0.8,0.9]), and increasing age, which was associated with a very slight reduction in the outcome (ARR 0.99 [0.98,0.99]). Maternal and neonatal outcomes did not vary by type of cesarean birth. CONCLUSION: Outcomes of cesarean birth do not seem to vary by timing of repeat cesarean birth, with hypertensive disease increasing the likelihood of pre-labor cesarean. This information might be useful in counseling women that outcomes after failed trial of labor do not appear worse than those after pre-labor cesarean birth.


Asunto(s)
Cesárea Repetida/métodos , Cesárea Repetida/estadística & datos numéricos , Adulto , Estudios de Cohortes , Femenino , Guatemala , Humanos , Embarazo , Factores de Riesgo , Factores Socioeconómicos
11.
Reprod Health ; 18(1): 99, 2021 May 21.
Artículo en Inglés | MEDLINE | ID: mdl-34020660

RESUMEN

OBJECTIVES: Our objectives were to analyze how pregnancy outcomes varied by cesarean birth as compared to vaginal birth across varying interpregnancy intervals (IPI) and determine if IPI modified mode of birth. METHODS: This secondary analysis used data from a prospective registry of home and hospital births in Chimaltenango, Guatemala from January 2017 through April 2020, through the Global Network for Women's and Children's Health Research. Bivariate comparisons and multivariable logistic regression were used to answer our study question, and the data was analyzed with STATA software v.15.1. RESULTS: Of 26,465 Guatemalan women enrolled in the registry, 2794 (10.6%) had a history of prior cesarean. 560 (20.1%) women delivered by vaginal birth after cesarean with the remaining 2,233 (79.9%) delivered by repeat cesarean. Repeat cesarean reduced the risk of needing a dilation and curettage compared to vaginal birth after cesarean, but this association did not vary by IPI, all p-values > p = 0.05. Repeat cesarean delivery, as compared to vaginal birth after cesarean, significantly reduced the likelihood a woman breastfeeding within one hour of birth (AOR ranged from 0.009 to 0.10), but IPI was not associated with the outcome. Regarding stillbirth, repeat cesarean birth reduced the likelihood of stillbirth as compared to vaginal birth (AOR 0.2), but again IPI was not associated with the outcome. CONCLUSION: Outcomes by mode of delivery among a Guatemalan cohort of women with a history of prior cesarean birth do not vary by IPI.


Asunto(s)
Intervalo entre Nacimientos/estadística & datos numéricos , Cesárea/estadística & datos numéricos , Resultado del Embarazo/epidemiología , Parto Vaginal Después de Cesárea/estadística & datos numéricos , Adulto , Cesárea/efectos adversos , Niño , Salud Infantil , Estudios de Cohortes , Femenino , Guatemala/epidemiología , Humanos , Recién Nacido , Trabajo de Parto , Embarazo , Estudios Retrospectivos , Factores de Tiempo , Salud de la Mujer
12.
Matern Child Nutr ; 17(4): e13204, 2021 10.
Artículo en Inglés | MEDLINE | ID: mdl-34036728

RESUMEN

Maternal iodine (I) status is critical in embryonic and foetal development. We examined the effect of preconception iodine supplementation on maternal iodine status and on birth outcomes. Non-pregnant women in Guatemala, India and Pakistan (n ~ 100 per arm per site) were randomized ≥ 3 months prior to conception to one of three intervention arms: a multimicronutrient-fortified lipid-based nutrient supplement containing 250-µg I per day started immediately after randomization (Arm 1), the same supplement started at ~12 weeks gestation (Arm 2) and no intervention supplement (Arm 3). Urinary I (µg/L) to creatinine (mg/dl) ratios (I/Cr) were determined at 12 weeks for Arm 1 versus Arm 2 (before supplement started) and 34 weeks for all arms. Generalized linear models were used to assess the relationship of I/Cr with arm and with newborn anthropometry. At 12 weeks gestation, adjusted mean I/Cr (µg/g) for all sites combined was significantly higher for Arm 1 versus Arm 2: (203 [95% CI: 189, 217] vs. 163 [95% CI: 152, 175], p < 0.0001). Overall adjusted prevalence of I/Cr < 150 µg/g was also lower in Arm 1 versus Arm 2: 32% (95% CI: 26%, 38%) versus 43% (95% CI: 37%, 49%) (p = 0.0052). At 34 weeks, adjusted mean I/Cr for Arm 1 (235, 95% CI: 220, 252) and Arm 2 (254, 95% CI: 238, 272) did not differ significantly but were significantly higher than Arm 3 (200, 95% CI: 184, 218) (p < 0.0001). Nominally significant positive associations were observed between I/Cr at 12 weeks and birth length and head circumference z-scores (p = 0.028 and p = 0.005, respectively). These findings support the importance of first trimester iodine status and suggest need for preconception supplementation beyond salt iodization alone.


Asunto(s)
Yodo , Suplementos Dietéticos , Femenino , Desarrollo Fetal , Humanos , Recién Nacido , Estado Nutricional , Embarazo , Primer Trimestre del Embarazo
13.
BMC Public Health ; 20(1): 687, 2020 May 14.
Artículo en Inglés | MEDLINE | ID: mdl-32410611

RESUMEN

BACKGROUND: The World Health Organization (WHO-2007) and the International Obesity Task Force (IOTF-Cole) systems assess child weight status. However, derived estimations often differ. We aimed to a) compare the prevalence of overweight and obesity, b) analyze individual and contextual factors associated with child weight using multilevel analysis and c) explore the spatial distribution of overweight and obesity using both classification systems. METHODS: We used data from the 2015/2016 National School Height and Weight Census in El Salvador. Information on 111,991 children aged 6.0-9.9 years attending the first grade was analyzed. Body mass index Z-score (BMIZ), overweight and obesity were defined with both classification systems. Weighted kappa was used to measure agreement. Child, school and municipal potential determinants of BMIZ were examined by multilevel analysis. Municipal spatial clustering of overweight and obesity was tested using Moran's Index and Getis-ord Gi* statistics. RESULTS: The combined prevalence of overweight and obesity was higher according to the WHO system than the IOTF (30.4% vs 23.1%). The weighted kappa was 0.83. Boys, children attending urban schools, children attending private schools, and children residing in municipalities with high human development index had higher BMIZ than their counterparts. The Moran's indexes were positives and significant. Clusters of high prevalence (above the national prevalence) of overweight and obesity were found in 29 municipalities using the WHO and IOTF systems. For obesity, 28 and 23 municipalities in clusters of high prevalence were detected using the WHO and IOTF criteria, respectively. CONCLUSIONS: Overweight and obesity is high among school-age children in El Salvador. The prevalence of overweight and obesity was higher when using the WHO system, as compared to the IOTF system. Irrespective of the classification system, the multilevel and spatial analysis derived similar interpretations. These results support the need for national preventive interventions with targeting strategies to reduce overweight and obesity in school-age children.


Asunto(s)
Índice de Masa Corporal , Peso Corporal , Obesidad Infantil/epidemiología , Vigilancia de la Población/métodos , Comités Consultivos , Niño , Ciudades , El Salvador/epidemiología , Femenino , Humanos , Masculino , Sobrepeso/clasificación , Sobrepeso/epidemiología , Obesidad Infantil/clasificación , Prevalencia , Características de la Residencia , Instituciones Académicas , Análisis Espacial , Población Urbana , Organización Mundial de la Salud
14.
Reprod Health ; 17(Suppl 2): 153, 2020 Nov 30.
Artículo en Inglés | MEDLINE | ID: mdl-33256772

RESUMEN

BACKGROUND: Congenital anomalies are a significant cause of death and disability for infants, especially in low and middle-income countries (LMIC), where 95% of all deaths due to anomalies occur. Limited data on the prevalence and survival of infants with congenital anomalies are available from Central America. Estimates have indicated that 53 of every 10,000 live births in Guatemala are associated with a congenital anomaly. We aim to report on the incidence and survival of infants with congenital anomalies from a population-based registry and classify the anomalies according to the International Classification of Disease, Tenth Revision (ICD-10). METHODS: We conducted a planned secondary analysis of data from the Maternal Newborn Health Registry (MNHR), a prospective, population-based study carried out by the Global Network for Women's and Children's Health Research in seven research sites. We included all deliveries between 2014 and 2018 in urban and rural settings in Chimaltenango, in the Western Highlands of Guatemala. These cases of clinically evident anomalies were reported by field staff and reviewed by medically trained staff, who classified them according to ICD - 10 categories. The incidence of congenital anomalies and associated stillbirth, neonatal mortality, and survival rates were determined for up to 42 days. RESULTS: Out of 60,142 births, 384 infants were found to have a clinically evident congenital anomaly (63.8 per 10,000 births). The most common were anomalies of the nervous system (28.8 per 10,000), malformations and deformations of the musculoskeletal system (10.8 per 10,000), and cleft lip and palate (10.0 per 10,000). Infants born with nervous system anomalies had the highest stillbirth and neonatal mortality rates (14.6 and 9.0 per 10,000, respectively). CONCLUSIONS: This is the first population-based report on congenital anomalies in Guatemala. The rates we found of overall anomalies are higher than previously reported estimates. These data will be useful to increase the focus on congenital anomalies and hopefully increase the use of interventions of proven benefit. TRIAL REGISTRATION: ClinalTrial.gov ID: NCT01073475 .


Asunto(s)
Anomalías Congénitas/epidemiología , Niño , Labio Leporino/epidemiología , Fisura del Paladar/epidemiología , Femenino , Guatemala/epidemiología , Humanos , Lactante , Recién Nacido , Clasificación Internacional de Enfermedades , Embarazo , Prevalencia , Estudios Prospectivos
15.
Reprod Health ; 17(Suppl 3): 193, 2020 Dec 17.
Artículo en Inglés | MEDLINE | ID: mdl-33334359

RESUMEN

BACKGROUND: Socioeconomic status (SES) is an important determinant of health globally and an important explanatory variable to assess causality in epidemiological research. The 10th Sustainable Development Goal is to reduce disparities in SES that impact health outcomes globally. It is easier to study SES in high-income countries because household income is representative of the SES. However, it is well recognized that income is poorly reported in low- and middle- income countries (LMIC) and is an unreliable indicator of SES. Therefore, there is a need for a robust index that will help to discriminate the SES of rural households in a pooled dataset from LMIC. METHODS: The study was nested in the population-based Maternal and Neonatal Health Registry of the Global Network for Women's and Children's Health Research which has 7 rural sites in 6 Asian, sub-Saharan African and Central American countries. Pregnant women enrolling in the Registry were asked questions about items such as housing conditions and household assets. The characteristics of the candidate items were evaluated using confirmatory factor analyses and item response theory analyses. Based on the results of these analyses, a final set of items were selected for the SES index. RESULTS: Using data from 49,536 households of pregnant women, we reduced the data collected to a 10-item index. The 10 items were feasible to administer, covered the SES continuum and had good internal reliability and validity. We developed a sum score-based Item Response Theory scoring algorithm which is easy to compute and is highly correlated with scores based on response patterns (r = 0.97), suggesting minimal loss of information with the simplified approach. Scores varied significantly by site (p < 0.001). African sites had lower mean SES scores than the Asian and Central American sites. The SES index demonstrated good internal consistency reliability (Cronbach's alpha = 0.81). Higher SES scores were significantly associated with formal education, more education, having received antenatal care, and facility delivery (p < 0.001). CONCLUSIONS: While measuring SES in LMIC is challenging, we have developed a Global Network Socioeconomic Status Index which may be useful for comparisons of SES within and between locations. Next steps include understanding how the index is associated with maternal, perinatal and neonatal mortality. Trial Registration NCT01073475 Socioeconomic status (SES) is an important determinant of health globally, and improving SES is important to reduce disparities in health outcomes. It is easier to study SES in high-income countries because it can be measured by income and what income is spent on, but this concept does not translate easily to low and middle income countries. We developed a questionnaire that includes 10 items to determine SES in low-resource settings that was added to an ongoing Maternal and Neonatal Health Registry that is funded by the National Institutes of Child Health and Human Development's Global Network. The Registry includes sites that collect outcomes of pregnancies in women and their babies in rural areas in 6 countries in South Asia, sub-Saharan Africa and Central America. The Registry is population based and tracks women from early in pregnancy to day 42 post-partum. The questionnaire is easy to administer and has good reliability and validity. Next steps include understanding how the index is associated with maternal, fetal and neonatal mortality.


Asunto(s)
Salud Infantil , Salud Materna , Clase Social , Determinantes Sociales de la Salud , Niño , Países en Desarrollo , Femenino , Salud Global , Disparidades en Atención de Salud , Humanos , Recién Nacido , Embarazo , Reproducibilidad de los Resultados , Encuestas y Cuestionarios
16.
Reprod Health ; 17(Suppl 3): 182, 2020 Dec 17.
Artículo en Inglés | MEDLINE | ID: mdl-33334362

RESUMEN

BACKGROUND: Nulliparity has been associated with lower birth weight (BW) and other adverse pregnancy outcomes, with most of the data coming from high-income countries. In this study, we examined birth weight for gestational age z-scores and neonatal (28-day) mortality in a large prospective cohort of women dated by first trimester ultrasound from multiple sites in low and middle-income countries. METHODS: Pregnant women were recruited during the first trimester of pregnancy and followed through 6 weeks postpartum from Maternal Newborn Health Registry (MNHR) sites in the Democratic Republic of Congo (DRC), Guatemala, Belagavi and Nagpur, India, and Pakistan from 2017 and 2018. Data related to the pregnancy and its outcomes were collected prospectively. First trimester ultrasound was used for determination of gestational age; (BW) was obtained in grams within 48 h of delivery and later transformed to weight for age z-scores (WAZ) adjusted for gestational age using the INTERGROWTH-21st standards. RESULTS: 15,121 women were eligible and included. Infants of nulliparous women had lower mean BWs (males: 2676 gr, females: 2587 gr, total: 2634 gr) and gestational age adjusted weight for age z-scores (males: - 0.73, females: - 0.77, total: - 0.75,) than women with one or more previous pregnancies. The largest differences were between zero and one previous pregnancies among female infants. The associations of parity with BW and z-scores remained even after adjustment for maternal age, maternal height, maternal education, antenatal care visits, hypertensive disorders, and socioeconomic status. Nulliparous women also had a significantly higher < 28-day neonatal mortality rate (27.7 per 1,000 live births) than parous women (17.2 and 20.7 for parity of 1-3 and ≥ 4 respectively). Risk of preterm birth was higher among women with ≥ 4 previous pregnancies (15.5%) compared to 11.3% for the nulliparous group and 11.8% for women with one to three previous pregnancies (p = 0.0072). CONCLUSIONS: In this large sample from diverse settings, nulliparity was independently associated with both lower BW and WAZ scores as well as higher neonatal mortality compared to multiparity.


Asunto(s)
Peso al Nacer , Paridad , Muerte Perinatal , Nacimiento Prematuro , Femenino , Humanos , Lactante , Salud del Lactante , Recién Nacido , Masculino , Embarazo , Resultado del Embarazo , Estudios Prospectivos , Sistema de Registros
17.
Reprod Health ; 17(Suppl 3): 179, 2020 Dec 17.
Artículo en Inglés | MEDLINE | ID: mdl-33334337

RESUMEN

BACKGROUND: Few studies have shown how the move toward institutional delivery in low and middle-income countries (LMIC) impacts stillbirth and newborn mortality. OBJECTIVES: The study evaluated trends in institutional delivery in research sites in Belagavi and Nagpur India, Guatemala, Kenya, Pakistan, and Zambia from 2010 to 2018 and compared them to changes in the rates of neonatal mortality and stillbirth. METHODS: We analyzed data from a nine-year interval captured in the Global Network (GN) Maternal Newborn Health Registry (MNHR). Mortality rates were estimated from generalized estimating equations controlling for within-cluster correlation. Cluster-level analyses were performed to assess the association between institutional delivery and mortality rates. RESULTS: From 2010 to 2018, a total of 413,377 deliveries in 80 clusters across 6 sites in 5 countries were included in these analyses. An increase in the proportion of institutional deliveries occurred in all sites, with a range in 2018 from 57.7 to 99.8%. In 2010, the stillbirth rates ranged from 19.3 per 1000 births in the Kenyan site to 46.2 per 1000 births in the Pakistani site and by 2018, ranged from 9.7 per 1000 births in the Belagavi, India site to 40.8 per 1000 births in the Pakistani site. The 2010 neonatal mortality rates ranged from 19.0 per 1000 live births in the Kenyan site to 51.3 per 1000 live births in the Pakistani site with the 2018 neonatal mortality rates ranging from 9.2 per 1000 live births in the Zambian site to 50.2 per 1000 live births in the Pakistani site. In multivariate modeling, in some but not all sites, the reductions in stillbirth and neonatal death were significantly associated with an increase in the institutional deliveries. CONCLUSIONS: There was an increase in institutional delivery rates in all sites and a reduction in stillbirth and neonatal mortality rates in some of the GN sites over the past decade. The relationship between institutional delivery and a decrease in mortality was significant in some but not all sites. However, the stillbirth and neonatal mortality rates remain at high levels. Understanding the relationship between institutional delivery and stillbirth and neonatal deaths in resource-limited environments will enable development of targeted interventions for reducing the mortality burden. TRIAL REGISTRATION: The study is registered at clinicaltrials.gov . ClinicalTrial.gov Trial Registration: NCT01073475 .


Asunto(s)
Parto Obstétrico/estadística & datos numéricos , Instituciones de Salud/estadística & datos numéricos , Mortalidad Infantil , Mortinato/epidemiología , Adulto , Parto Obstétrico/métodos , Femenino , Humanos , Lactante , Salud del Lactante , Recién Nacido , Masculino , Edad Materna , Embarazo , Sistema de Registros
18.
Reprod Health ; 17(Suppl 3): 165, 2020 Dec 17.
Artículo en Inglés | MEDLINE | ID: mdl-33334352

RESUMEN

BACKGROUND: The objectives of this analysis were to document trends in and risk factors associated with the cesarean birth rate in low- and middle-income country sites participating in the Global Network for Women's and Children's Health Research (Global Network). METHODS: This is a secondary analysis of a prospective, population-based study of home and facility births conducted in the Global Network sites. RESULTS: Cesarean birth rates increased uniformly across all sites between 2010 and 2018. Across all sites in multivariable analyses, women younger than age twenty had a reduced risk of cesarean birth (RR 0.9 [0.9, 0.9]) and women over 35 had an increased risk of cesarean birth (RR 1.1 [1.1, 1.1]) compared to women aged 20 to 35. Compared to women with a parity of three or more, less parous women had an increased risk of cesarean (RR 1.2 or greater [1.2, 1.4]). Four or more antenatal visits (RR 1.2 [1.2, 1.3]), multiple pregnancy (RR 1.3 [1.3, 1.4]), abnormal progress in labor (RR 1.1 [1.0, 1.1]), antepartum hemorrhage (RR 2.3 [2.0, 2.7]), and hypertensive disease (RR 1.6 [1.5, 1.7]) were all associated with an increased risk of cesarean birth, p < 0.001. For multiparous women with a history of prior cesarean birth, rates of vaginal birth after cesarean were about 20% in the Latin American and Southeast Asian sites and about 84% at the sub-Saharan African sites. In the African sites, proportions of cesarean birth in the study were highest among women without a prior cesarean and a single, cephalic, term pregnancy. In the non-African sites, groups with the greatest proportion of cesarean births were nulliparous women with a single, cephalic, term pregnancy and all multiparous women with at least one previous uterine scar with a term, cephalic pregnancy. CONCLUSION: Cesarean birth rates continue to rise within the Global Network. The proportions of cesarean birth are higher among women with no history of cesarean birth in the African sites and among women with primary elective cesarean, primary cesarean after induction, and repeat cesarean in the non-African sites.


Asunto(s)
Tasa de Natalidad , Cesárea/estadística & datos numéricos , Cesárea/tendencias , Salud Infantil , Parto Vaginal Después de Cesárea/estadística & datos numéricos , Adulto , Cesárea/efectos adversos , Niño , Femenino , Humanos , Recién Nacido , Paridad , Vigilancia de la Población , Embarazo , Estudios Prospectivos , Factores de Riesgo , Adulto Joven
19.
Reprod Health ; 17(Suppl 3): 187, 2020 Dec 17.
Artículo en Inglés | MEDLINE | ID: mdl-33334356

RESUMEN

BACKGROUND: Preterm birth continues to be a major public health problem contributing to 75% of the neonatal mortality worldwide. Low birth weight (LBW) is an important but imperfect surrogate for prematurity when accurate assessment of gestational age is not possible. While there is overlap between preterm birth and LBW newborns, those that are both premature and LBW are at the highest risk of adverse neonatal outcomes. Understanding the epidemiology of preterm birth and LBW is important for prevention and improved care for at risk newborns, but in many countries, data are sparse and incomplete. METHODS: We conducted data analyses using the Global Network's (GN) population-based registry of pregnant women and their babies in rural communities in six low- and middle-income countries (Democratic Republic of Congo, Kenya, Zambia, Guatemala, India and Pakistan). We analyzed data from January 2014 to December 2018. Trained study staff enrolled all pregnant women in the study catchment area as early as possible during pregnancy and conducted follow-up visits shortly after delivery and at 42 days after delivery. We analyzed the rates of preterm birth, LBW and the combination of preterm birth and LBW and studied risk factors associated with these outcomes across the GN sites. RESULTS: A total of 272,192 live births were included in the analysis. The overall preterm birth rate was 12.6% (ranging from 8.6% in Belagavi, India to 21.8% in the Pakistani site). The overall LBW rate was 13.6% (ranging from 2.7% in the Kenyan site to 21.4% in the Pakistani site). The overall rate of both preterm birth and LBW was 5.5% (ranging from 1.2% in the Kenyan site to 11.0% in the Pakistani site). Risk factors associated with preterm birth, LBW and the combination were similar across sites and included nulliparity [RR - 1.27 (95% CI 1.21-1.33)], maternal age under 20 [RR 1.41 (95% CI 1.32-1.49)] years, severe antenatal hemorrhage [RR 5.18 95% CI 4.44-6.04)], hypertensive disorders [RR 2.74 (95% CI - 1.21-1.33], and 1-3 antenatal visits versus four or more [RR 1.68 (95% CI 1.55-1.83)]. CONCLUSIONS: Preterm birth, LBW and their combination continue to be common public health problems at some of the GN sites, particularly among young, nulliparous women who have received limited antenatal care services. Trial registration The identifier of the Maternal and Newborn Health Registry at ClinicalTrials.gov is NCT01073475. TRIAL REGISTRATION: The identifier of the Maternal and Newborn Health Registry at ClinicalTrials.gov is NCT01073475.


Asunto(s)
Recién Nacido de Bajo Peso , Nacimiento Prematuro/epidemiología , Peso al Nacer , Países en Desarrollo , Femenino , Humanos , Lactante , Recién Nacido , Embarazo , Factores de Riesgo
20.
Reprod Health ; 17(Suppl 3): 176, 2020 Dec 17.
Artículo en Inglés | MEDLINE | ID: mdl-33334365

RESUMEN

BACKGROUND: Birth weight (BW) is a strong predictor of neonatal outcomes. The purpose of this study was to compare BWs between global regions (south Asia, sub-Saharan Africa, Central America) prospectively and to determine if trends exist in BW over time using the population-based maternal and newborn registry (MNHR) of the Global Network for Women'sand Children's Health Research (Global Network). METHODS: The MNHR is a prospective observational population-based registryof six research sites participating in the Global Network (2013-2018), within five low- and middle-income countries (Kenya, Zambia, India, Pakistan, and Guatemala) in threeglobal regions (sub-Saharan Af rica, south Asia, Central America). The birth weights were obtained for all infants born during the study period. This was done either by abstracting from the infants' health facility records or from direct measurement by the registry staff for infants born at home. After controlling for demographic characteristics, mixed-effect regression models were utilized to examine regional differences in birth weights over time. RESULTS: The overall BW meanswere higher for the African sites (Zambia and Kenya), 3186 g (SD 463 g) in 2013 and 3149 g (SD 449 g) in 2018, ascompared to Asian sites (Belagavi and Nagpur, India and Pakistan), 2717 g (SD450 g) in 2013 and 2713 g (SD 452 g) in 2018. The Central American site (Guatemala) had a mean BW intermediate between the African and south Asian sites, 2928 g (SD 452) in 2013, and 2874 g (SD 448) in 2018. The low birth weight (LBW) incidence was highest in the south Asian sites (India and Pakistan) and lowest in the African sites (Kenya and Zambia). The size of regional differences varied somewhat over time with slight decreases in the gap in birth weights between the African and Asian sites and slight increases in the gap between the African and Central American sites. CONCLUSIONS: Overall, BWmeans by global region did not change significantly over the 5-year study period. From 2013 to 2018, infants enrolled at the African sites demonstrated the highest BW means overall across the entire study period, particularly as compared to Asian sites. The incidence of LBW was highest in the Asian sites (India and Pakistan) compared to the African and Central American sites. Trial registration The study is registered at clinicaltrials.gov. ClinicalTrial.gov Trial Registration: NCT01073475.


Asunto(s)
Peso al Nacer , Países en Desarrollo , Mortalidad Infantil/tendencias , África , Asia , América Central , Niño , Estudios de Cohortes , Femenino , Salud Global , Humanos , Lactante , Mortalidad Infantil/etnología , Recién Nacido de Bajo Peso , Recién Nacido , Estudios Longitudinales , Masculino , Estudios Prospectivos
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