Birth weight and asthma in young adults of a Brazilian birth cohort.

This article aims to evaluate the association between birth weight and asthma in adulthood, estimated by employing structural equation modeling. Cohort study with 1,958 participants aged 23-25 years from Ribeirão Preto, São Paulo, Brazil. Standardized questionnaires were applied and pulmonary function evaluated, including bronchial reactivity with methacholine. A theoretical model was proposed to explore the effects of birth weight and asthma in adulthood. Asthma, socioeconomic status at birth (Birth SES), and current socioeconomic status (Adult SES) were obtained by constructs. Maternal age, sex, skin color, body mass index (BMI), smoking, parental asthma history, history of respiratory infection before five years old, history of hospitalization for lung disease before two years old, and atopy were the studied variables. 14.1% of participants were diagnosed with asthma. Birth weight was associated with asthma (Standardized Coefficient - SCtotal=-0.110; p=0.030), and an indirect effect was also observed (SCindirect=-0.220; p=0.037), mediated by hospitalization before two years and respiratory infection before five years. Lower birth weight showed an increased risk of asthma in adulthood and the SES Birth and Adult SES variables underlie this association.

Association between placental efficiency with anthropometry and nutritional phenotypes in full-term newborns from the 2010/2011 BRISA birth cohort.

OBJECTIVE: To study the association between placental efficiency with anthropometry and nutritional phenotypes in full-term newborns from a birth cohort. METHOD: This was a secondary cross-sectional analysis of data obtained in a cohort study (Brazilian RibeirãoPreto and São Luís Birth Cohort Studies - BRISA), whose deliveries were performed between 2010 and 2011. Standardized questionnaires were applied to mothers, and placentas and newborns were evaluated shortly after delivery. Placental efficiency was assessed using the ratio between birth weight and placental weight (BW/PW ratio); values below the lower quartile (25th percentile for gestational age) were considered to have low placental efficiency. Newborn phenotypes were small and large for gestational age, stunted and wasted, evaluated using the INTERGROWTH-21 growth standard. To identify the confounding variables theoretical model was constructed using Directed Acyclic Graphs, and unadjusted and adjusted logistic regression were performed. Placental measurements were obtained blindly from pregnancy and delivery data. RESULTS: 723 mother-placenta-child triads were studied. 3.2 % of newborns were small-for-gestational-age (SGA), 6.5 %large-for-gestational-age (LGA), 5.7 %had stunting, and 0.27 % wasting. A significantly higher risk was found between low placental efficiency and SGA (OR 2.82;95 % CI 1.05-7.57), stunting (OR 2.23; 95 % CI 1.07-4.65), and wasting (OR 8.22; 95 % CI 1.96-34.37). No relationship was found between LGA and placental efficiency. CONCLUSIONS: Low placental efficiency was associated with increased risk for small-for-gestational-age, stunting, and wasting. Placental morphometry can provide valuable information on intrauterine conditions and neonatal health, helping to identify newborns at higher risk of future comorbidities.

Gestational weight gain charts for Latin American adolescents.

Monitoring gestational weight gain (GWG) throughout pregnancy among adolescents is important for detecting individuals at risk and timely intervention. However, there are no specific tools or guidelines for GWG monitoring of this group. We aimed to construct GWG charts for pregnant adolescents (10-19 years old) according to pre-pregnancy body mass index (BMI) using a pooled dataset from nine Latin American countries. Datasets from Argentina, Brazil, Chile, Colombia, Mexico, Panama, Paraguay, Peru, and Uruguay collected between 2003 and 2021 were combined after data cleaning and harmonization. Adolescents free of diseases that could affect GWG and who gave birth to newborns weighing between 2,500-4,000 g and free of congenital malformations were included. Multiple imputation techniques were applied to increase the sample size available for underweight and obesity categories. Generalized Additive Models for Location, Scale, and Shape were used to construct the charts of GWG according to gestational age. Internal and external validation procedures were performed to ensure that models were not over-adjusted to the data. The cohort included 6,414 individuals and 29,414 measurements to construct the charts and 1,684 individuals and 8,879 measurements for external validation. The medians (and interquartile ranges) for GWG at 40 weeks according to pre-pregnancy BMI were: underweight, 14.9 (11.9-18.6); normal weight, 14.0 (10.6-17.7); overweight, 11.6 (7.7-15.6); obesity, 10.6 kg (6.7-14.3). Internal and external validation showed that the percentages above/below selected percentiles were close to those expected, except for underweight adolescents. These charts describe the GWG throughout pregnancy among Latin American adolescents and represent a significant contribution to the prenatal care of this group. GWG cut-offs based on values associated with lower risks of unfavorable outcomes for the mother-child binomial should be determined before implementing the charts in clinical practice.

Growth phenotypes of very low birth weight infants for prediction of neonatal outcomes from a Brazilian cohort: comparison with INTERGROWTH

Abstract Objective: To assess the predictive value of selected growth phenotypes for neonatal morbidity and mortality in preterm infants < 30 weeks and to compare them with INTERGROWTH-21st (IG21). Methods: Retrospective analysis of data from the Brazilian Neonatal Research Network (BNRN) database for very low birth weight (VLBW) at 20 public tertiary-care university hospitals. Outcome: the composite neonatal morbidity and mortality (CNMM) consisted of in-hospital death, oxygen use at 36 weeks, intraventricular hemorrhage grade 3 or 4, and Bell stage 2 or 3 necrotizing enterocolitis. Selected growth phenotypes: small-for-gestational-age (SGA) defined as being < 3rd (SGA3) or 10th (SGA10) percentiles of BW, and large-for-gestational-age (LGA) as being > 97th percentile of BW. Stunting as being < 3rd percentile of the length and wasting as being < 3rd percentile of BMI. Single and multiple log-binomial regression models were fitted to estimate the relative risks of CNMM, comparing them to IG21. Results: 4,072 infants were included. The adjusted relative risks of CNMM associated with selected growth phenotypes were (BNRN/IG21): 1.45 (0.92-2.31)/1.60 (1.27-2.02) for SGA; 0.90 (0.55-1.47)/1.05 (0.55-1.99) for LGA; 1.65 (1.08-2.51)/1.58 (1.28-1.96) for stunting; and 1.48 (1.02-2.17) for wasting. Agreement between the two references was variable. The growth phenotypes had good specificity (>95%) and positive predictive value (70-90%), with poor sensitivity and low negative predictive value. Conclusion: The BNRN phenotypes at birth differed markedly from the IG21 standard and showed poor accuracy in predicting adverse neonatal outcomes.

Growth phenotypes of very low birth weight infants for prediction of neonatal outcomes from a Brazilian cohort: comparison with INTERGROWTH.

OBJECTIVE: To assess the predictive value of selected growth phenotypes for neonatal morbidity and mortality in preterm infants < 30 weeks and to compare them with INTERGROWTH-21st (IG21). METHOD: Retrospective analysis of data from the Brazilian Neonatal Research Network (BNRN) database for very low birth weight (VLBW) at 20 public tertiary-care university hospitals. OUTCOME: the composite neonatal morbidity and mortality (CNMM) consisted of in-hospital death, oxygen use at 36 weeks, intraventricular hemorrhage grade 3 or 4, and Bell stage 2 or 3 necrotizing enterocolitis. Selected growth phenotypes: small-for-gestational-age (SGA) defined as being < 3rd (SGA3) or 10th (SGA10) percentiles of BW, and large-for-gestational-age (LGA) as being > 97th percentile of BW. Stunting as being < 3rd percentile of the length and wasting as being < 3rd percentile of BMI. Single and multiple log-binomial regression models were fitted to estimate the relative risks of CNMM, comparing them to IG21. RESULTS: 4,072 infants were included. The adjusted relative risks of CNMM associated with selected growth phenotypes were (BNRN/IG21): 1.45 (0.92-2.31)/1.60 (1.27-2.02) for SGA; 0.90 (0.55-1.47)/1.05 (0.55-1.99) for LGA; 1.65 (1.08-2.51)/1.58 (1.28-1.96) for stunting; and 1.48 (1.02-2.17) for wasting. Agreement between the two references was variable. The growth phenotypes had good specificity (>95%) and positive predictive value (70-90%), with poor sensitivity and low negative predictive value. CONCLUSION: The BNRN phenotypes at birth differed markedly from the IG21 standard and showed poor accuracy in predicting adverse neonatal outcomes.

Associations between child and adolescent marriage and reproductive outcomes in Brazil, Ecuador, the United States and Canada.

BACKGROUND: Although marriage is associated with favourable reproductive outcomes among adult women, it is not known whether the marriage advantage applies to girls (< 18 years). The contribution of girl child marriage (< 18 years) to perinatal health is understudied in the Americas. METHODS: National singleton birth registrations were used to estimate the prevalence of girl child marriage among mothers in Brazil (2011-2018, N = 23,117,661), Ecuador (2014-2018, N = 1,519,168), the USA (2014-2018, N = 18,618,283) and Canada (2008-2018, N = 3,907,610). The joint associations between marital status and maternal age groups (< 18, 18-19 and 20-24 years) with preterm birth (< 37 weeks), small-for-gestational age (SGA < 10 percentile) and repeat birth were assessed with logistic regression. RESULTS: The proportion of births to < 18-year-old mothers was 9.9% in Ecuador, 8.9% in Brazil, 1.5% in the United States and 0.9% in Canada, and marriage prevalence among < 18-year-old mothers was 3.0%, 4.8%, 3.7% and 1.7%, respectively. In fully-adjusted models, marriage was associated with lower odds of preterm birth and SGA among 20-24-year-old mothers in the four countries. Compared to unmarried 20-24-year-old women, married and unmarried < 18-year-old girls had higher odds of preterm birth in the four countries, and slightly higher odds of SGA in Brazil and Ecuador but not in the USA and Canada. In comparisons within age groups, the odds of repeat birth among < 18-year-old married mothers exceeded that of their unmarried counterparts in Ecuador [AOR: 1.99, 95%CI: 1.82, 2.18], the USA [AOR: 2.96, 95%CI: 2.79, 3.14], and Canada [AOR: 2.17, 95%CI: 1.67, 2.82], although minimally in Brazil [AOR: 1.09, 95%CI: 1.07, 1.11]. CONCLUSIONS: The prevalence of births to < 18-year-old mothers varies considerably in the Americas. Girl child marriage was differentially associated with perinatal health indicators across countries, suggesting context-specific mechanisms.

The perinatal epidemiology of child and adolescent marriage in Brazil, 2011-2018.

Brazil is one of the top contributors of girl child marriages in the world and one of the United Nations' members that committed to end child marriage by 2030 as part of the Sustainable Development Goals. Child marriage is an indicator of gender inequality associated with poor health outcomes. However, the perinatal epidemiology of minor mothers (<18 years) according to marital status has been insufficiently studied. We used 23,163,209 birth registrations (2011-2018) to describe the sociodemographic distribution of births to minor mothers. The association between adverse outcomes and marital status and maternal age was restricted to 7,953,739 births of mothers aged ≤15, 16-17, 18-19, 20-24 years. Multinomial logistic models were used for very (24-31 weeks) and moderately preterm birth (32-36 weeks), and severe (<3rd percentile) and moderately small-for-gestational age (SGA) (3rd to <10th percentile). Logistic models were used for binary outcomes. The proportion of births to minor mothers in the study period was 8.9%, composed of those of single (6.1%), common-law (2.4%) and married girls (0.4%). Births to minor mothers decreased over time (p-value <0.001), were more common in the North Region (13.2%) and among Indigenous (17.4%). Very and moderately preterm birth increased with decreasing age but within each age group, rates were highest among single, followed by common-law and lowest among married mothers. A similar pattern was observed for SGA, low Apgar and late prenatal care initiation. Repeat birth and low age-appropriate education were less common among married compared to single mothers in all age groups, except among ≤15-year-olds [Adjusted Odds Ratio (AOR): 2.56; 95% Confidence Interval (95%CI): 2.40, 2.74 and AOR: 1.30; 95%CI: 1.03, 1.64, respectively]. The association between perinatal indicators and marital status among adolescents is strongly modified by decreasing maternal age. Marital status is relevant for the understanding of early pregnancies.

Abuse, disrespect and mistreatment during childbirth care: contribution of the Ribeirão Preto cohorts, Brazil.

This study aimed to estimate the perception and frequency of abuse, disrespect and mistreatment (ADM) situations during childbirth care of 745 women from the Ribeirão Preto birt cohorts. Confidential questionnaires containing one question regarding perceived abuse during childbirth care and other questions addressing exposure to ADM situations were applied. The chi-squared test was used to compare the situations presented between women who did and did not report mistreatment using the Stata 14.0 software. Among the 745 women evaluated, 66.2% were exposed to some situation of ADM and 8.3% reported having perceived ADM. The most frequent situations were that the woman could not eat or drink (30.5%), the woman had her belly squeezed to help the child be born (27.5%), and the woman could not stay with a companion of her choice (25.5%). Women who reported to have suffered maltreatment more frequently responded positively to all situations of ADM when compared to the other participants, except for the following statements: "I was not allowed to eat or drink anything" (p = 0.975) and "I was forced to have a cesarean delivery against my will" (p = 0.073). Although most women of the Ribeirão Preto cohorts reported exposure to ADM situations during childbirth care, a minority perceived disrespect or mistreatment.

Abuse, disrespect and mistreatment during childbirth care: contribution of the Ribeirão Preto cohorts, Brazil / Abuso, desrespeito e maltrato na assistência ao parto: contribuição das Coortes de Ribeirão Preto, Brasil

Abstract This study aimed to estimate the perception and frequency of abuse, disrespect and mistreatment (ADM) situations during childbirth care of 745 women from the Ribeirão Preto birt cohorts. Confidential questionnaires containing one question regarding perceived abuse during childbirth care and other questions addressing exposure to ADM situations were applied. The chi-squared test was used to compare the situations presented between women who did and did not report mistreatment using the Stata 14.0 software. Among the 745 women evaluated, 66.2% were exposed to some situation of ADM and 8.3% reported having perceived ADM. The most frequent situations were that the woman could not eat or drink (30.5%), the woman had her belly squeezed to help the child be born (27.5%), and the woman could not stay with a companion of her choice (25.5%). Women who reported to have suffered maltreatment more frequently responded positively to all situations of ADM when compared to the other participants, except for the following statements: "I was not allowed to eat or drink anything" (p = 0.975) and "I was forced to have a cesarean delivery against my will" (p = 0.073). Although most women of the Ribeirão Preto cohorts reported exposure to ADM situations during childbirth care, a minority perceived disrespect or mistreatment.

Resumo O objetivo do estudo foi estimar percepção e ocorrência de situações de abuso, desrespeito e maltrato (ADM) na assistência ao parto de 745 mulheres pertencentes às coortes de nascimentos de Ribeirão Preto. Foram aplicados questionários sigilosos contendo uma pergunta sobre percepção de maltrato na assistência ao parto e outras sobre exposição a situações de ADM. Utilizou-se o teste qui-quadrado para comparar as situações apresentadas entres as mulheres que relataram ou não maltrato. A análise foi realizada por meio do programa Stata 14. Das 745 mulheres avaliadas, 66,2% foram expostas a alguma situação de ADM e 8,3% referiram ter percebido ADM. As situações mais frequentes foram: 30,5% não puderam comer nem beber nada; 27,5% tiveram sua barriga apertada para ajudar a criança a nascer; e 25,5% não puderam ficar com acompanhante de sua escolha. Mulheres que afirmaram ter sofrido maltrato apresentaram maiores frequências de respostas positivas a todas situações de ADM quando comparadas com às demais, exceto para os seguintes relatos: "Não me deixaram comer nem beber nada" (p = 0,975) e "Fui forçada a ter parto cesáreo contra minha vontade" (p = 0,073). Apesar de a maior parte das mulheres pertencentes às coortes de Ribeirão Preto relatarem exposição a situações de ADM durante a assistência ao parto, uma minoria percebeu desrespeito ou maltrato.

Weight/length ratio references and newborn body composition estimation at birth from a Brazilian cohort

Abstract Objectives: The objective was to calculate weight/length (W/L) ratio values and percentiles by sex and gestational age (GA) to estimate fat mass (FM), fat-free mass (FFM) and body fat percentage (BF%) as well as to compare these indices in preterm, small (SGA), and large (LGA) for GA, stunted and wasted infants from a Brazilian cohort of newborns, comparing with the INTERGROWTH-21st. Methods: Secondary, cross-sectional analysis of data obtained of 7427 live-born infants from the BRISA Cohort Study in the city of Ribeirão Preto, SP, Brazil in 2010. For body composition estimation, W/L ratio was used in multiple regression models. The 3rd, 50th, and 97th percentiles for W/L ratio and body composition measures (FM, FFM, and BF%) were calculated using fractional polynomial regression models. Results: Average W/L ratio was 6.50 kg/m (SD 0.87), while for FM, BF%, and FFM the corresponding values were 359.64 g (145.76), 10.90% (3.05) and 2798.84 g (414.84), respectively. SGA (< 3rd percentile), and wasted infants showed the lowest W/L ratios and measures of body composition. The 3rd, 50th, and 97th percentiles charts of W/L, FM, BF%, and FFM by GA and sex are presented. Conclusions: W/L ratio values of the RP-BRISA Cohort are higher than IG-21st. SGA (< 3rd) and wasted infants showed the lowest W/L ratio and measures of body composition. The body composition references presented here could be used to refine the nutritional assessment of Brazilian newborns and to facilitate comparisons across populations.

Alterations in fetal kidney development and increased risk for adult diseases. / Desarrollo renal fetal alterado y riesgo aumentado de enfermedades del adulto.

A low birth weight (LBW, < 2500 g), intrauterine growth restriction (IUGR), and preterm birth (PB, < 37 weeks of gestational age) are the most common clinical factors for an altered programming of nephron number and are associated with a greater risk for hypertension, proteinuria, and kidney disease later in life. At present, an indirect assessment of total nephron number based on postnatal markers is the most important approach to evaluate the risk for future kidney disorders in newborn infants with a LBW, IUGR or PB. Here we describe advances made in animal experiments and biochemical markers in humans, and the recommendations for the prevention of preconception kidney injury, including social factors and chronic diseases. According to the evidence, IUGR and prematurity alone can modulate nephrogenesis and kidney function, and, if occurring simultaneously, their effects tend to be cumulative.

El bajo peso al nacer (BP, < 2500 g), la restricción del crecimiento intrauterino (RCIU) y el parto prematuro (PP, < 37 semanas de gestación) son los factores clínicos más habituales para la programación alterada del número de nefronas y se asocian con un mayor riesgo de hipertensión, proteinuria y enfermedad renal futura en la vida. En la actualidad la evaluación indirecta del número total de nefronas mediante el uso de marcadores en el período posnatal representa el enfoque principal para evaluar el riesgo de evolución futura de los trastornos renales en los recién nacidos con BP, RCIU o PP. Se presentan los avances en la investigación en animales y sobre marcadores bioquímicos en humanos, y recomendaciones para la prevención del daño renal preconcepcional, incluidos los factores sociales y las enfermedades crónicas. La evidencia demuestra que la restricción de crecimiento y la prematuridad solas son capaces de modular la nefrogénesis y la función renal y, cuando son concurrentes, sus efectos tienden a ser acumulativos.

Desarrollo renal fetal alterado y riesgo aumentado de enfermedades del adulto / Alterations in fetal kidney development and increased risk for adult diseases

El bajo peso al nacer (BP, < 2500 g), la restricción del crecimiento intrauterino (RCIU) y el parto prematuro (PP, < 37 semanas de gestación) son los factores clínicos más habituales para la programación alterada del número de nefronas y se asocian con un mayor riesgo de hipertensión, proteinuria y enfermedad renal futura en la vida. En la actualidad la evaluación indirecta del número total de nefronas mediante el uso de marcadores en el período posnatal representa el enfoque principal para evaluar el riesgo de evolución futura de los trastornos renales en los recién nacidos con BP, RCIU o PP.Se presentan los avances en la investigación en animales y sobre marcadores bioquímicos en humanos, y recomendaciones para la prevención del daño renal preconcepcional, incluidos los factores sociales y las enfermedades crónicas. La evidencia demuestra que la restricción de crecimiento y la prematuridad solas son capaces de modular la nefrogénesis y la función renal y, cuando son concurrentes, sus efectos tienden a ser acumulativos.

A low birth weight (LBW, < 2500 g), intrauterine growth restriction (IUGR), and preterm birth (PB, < 37 weeks of gestational age) are the most common clinical factors for an altered programming of nephron number and are associated with a greater risk for hypertension, proteinuria, and kidney disease later in life. At present, an indirect assessment of total nephron number based on postnatal markers is the most important approach to evaluate the risk for future kidney disorders in newborn infants with a LBW, IUGR or PB.Here we describe advances made in animal experiments and biochemical markers in humans, and the recommendations for the prevention of preconception kidney injury, including social factors and chronic diseases. According to the evidence, IUGR and prematurity alone can modulate nephrogenesis and kidney function, and, if occurring simultaneously, their effects tend to be cumulative.

Relationship between metalloproteinase-2 and -9 levels in plasma and vaginal secretion with preterm birth.

OBJECTIVE: To study the association of plasma and vaginal levels of matrix metalloproteinases 2 (MMP-2) and 9 (MMP-9), determined between 20+0 and 25+6 weeks of gestation, with preterm birth and its predictive value. STUDY DESIGN: All 129 cases of preterm birth (cases) and 258 randomly selected term patients (control group) were included in a cohort study with a nested case-control design. Inclusion criteria were living in Ribeirão Preto, Brazil, and gestational age 20+0 to 25+6 at enrollment. Exclusion criteria were multiple fetuses, congenital malformations or chromosome syndromes, and loss to follow-up. Maternal age, parity, smoking, and previous preterm birth were included as covariates. A blood sample and vaginal secretion were obtained for the determination of MMP-2 and MMP-9; the patients were screened for urinary tract infection and bacterial vaginosis, and cervical length was measured by ultrasound. The cut-off values for matrix metalloproteinases were calculated using receiver operating characteristic (ROC) curves for logistic regression analysis (crude and adjusted odds ratios). RESULTS: According to the WHO, in this study, preterm subtypes included 3.8 % extremely preterm, 6.9 % very preterm, and 89.2 % late preterm births. The plasma MMP-9 cut-off was 63.25 ng/mL and the area under the ROC curve was 0.725 (standard error 0.03; 95 % confidence interval, 0.677-0.769). The cut-off for plasma MMP-2 was 239.4 ng/mL and the area under the ROC curve was 0.585 (standard error 0.03, 95 % confidence interval, 0.521-0.649). Crude odds ratios showed an increased risk of preterm birth associated with plasma MMP-2 (odds ratio, 1.75; 95 % confidence interval, 1.14-2.68) and plasma MMP-9 (odds ratio, 3.26, 95 % confidence interval, 2.09-5.07); no association was detected for vaginal MMP-2 or 9. For plasma, adjusted odds ratios were 1.42 (95 % confidence interval, 0.80-2.53) for MMP-2 and 2.71 (95 % confidence interval, 1 .52-4.83) for MMP-9, along with an increased risk in other covariates. CONCLUSION: Elevated plasma MMP-9 levels and decreased MMP-2 levels were positively associated with preterm birth. Plasma MMP-9 level increased nearly three times the preterm risk.

Weight/length ratio references and newborn body composition estimation at birth from a Brazilian cohort.

OBJECTIVES: The objective was to calculate weight/length (W/L) ratio values and percentiles by sex and gestational age (GA) to estimate fat mass (FM), fat-free mass (FFM) and body fat percentage (BF%) as well as to compare these indices in preterm, small (SGA), and large (LGA) for GA, stunted and wasted infants from a Brazilian cohort of newborns, comparing with the INTERGROWTH-21st. METHODS: Secondary, cross-sectional analysis of data obtained of 7427 live-born infants from the BRISA Cohort Study in the city of Ribeirão Preto, SP, Brazil in 2010. For body composition estimation, W/L ratio was used in multiple regression models. The 3rd, 50th, and 97th percentiles for W/L ratio and body composition measures (FM, FFM, and BF%) were calculated using fractional polynomial regression models. RESULTS: Average W/L ratio was 6.50 kg/m (SD 0.87), while for FM, BF%, and FFM the corresponding values were 359.64 g (145.76), 10.90% (3.05) and 2798.84 g (414.84), respectively. SGA (< 3rd percentile), and wasted infants showed the lowest W/L ratios and measures of body composition. The 3rd, 50th, and 97th percentiles charts of W/L, FM, BF%, and FFM by GA and sex are presented. CONCLUSIONS: W/L ratio values of the RP-BRISA Cohort are higher than IG-21st. SGA (< 3rd) and wasted infants showed the lowest W/L ratio and measures of body composition. The body composition references presented here could be used to refine the nutritional assessment of Brazilian newborns and to facilitate comparisons across populations.

Proportionality indices, geographic altitude, and gestational age in newborns from Jujuy, Argentina.

BACKGROUND: There are several different proportionality indices (PRIs) to evaluate size at birth by gestational age (GA). Yet, the explanatory power of alternative PRIs has not been evaluated in highland (HL) populations. AIM: Evaluate the relative utility of three PRIs, weight to length ratio (W/L), body mass index (BMI), and ponderal index (PI), for assessing nutritional status in newborns (NBs) from highland (HL ≥ 2000 m) and lowland (LL < 2000 m) regions of the Jujuy Province of Argentina. SUBJECTS AND METHODS: Births were registered by the Ministry of Health (Jujuy, 2009-2014). Data were grouped according to HL and LL altitude groups based on of maternal residence. The main outcome measures were the PRIs W/L ratio, BMI, and PI. Percentiles were generated by the LMS method and compared with references. ANOVAs and Pearson correlations were used to examine the relationship between outcome measures with weight and length by altitude, sex, and GA. RESULTS: In both altitude zones, W/L and BMI increased with GA, while PI stabilized between 37th and 42th weeks. The LL sample had significantly higher values for all the PRIs from the 37th week of GA. In the HL sample, the 50th percentiles for all three PRIs were lower than the reference. Regardless of GA and altitude level, BMI showed the lowest correlation with length and the higher with the weight. CONCLUSION: The HL sample of term NBs had lower values for all PRIs compared to their LL counterparts. In both altitude zones, the BMI is the preferred PRI to evaluate the nutritional status.

Comparison of birth weight, length, and head circumference between the BRISA-RP and Intergrowth-21st cohorts, / Comparação de peso, comprimento e perímetro cefálico ao nascer entre Coorte BRISA-RP e Intergrowth-21st,

Abstract Objectives: (a) To determine the 3rd, 50th, and 97th percentiles of weight, length, and head circumference of newborns from the Ribeirão Preto BRISA cohort, according to gender and gestational age, and compare them with the Intergrowth-21st standard; (b) To estimate the small for gestational age ( < 3rd percentile), large for gestational age ( > 97th percentile), stunting (length < 3rd percentile), and wasting (body mass index < 3rd percentile). Methods: Observational study of a cohort of 7702 newborns between 01/01/2010 and 12/31/2010 in the city of Ribeirão Preto, SP, Brazil. The 3rd, 50th, and 97th percentiles were determined for the anthropometric measurements using fractional polynomial regression. Results: The weight difference between Ribeirão Preto and Intergrowth-21st was small, being more pronounced in preterm infants (mean difference between the two populations of +266 g); for full-term newborns, there was a mean difference of +66 g, and for post-term infants, of -113 g. For length, the mean variation was always <1 cm; whereas for head circumference, preterm newborns showed a variation >1 cm, and full-term and post-term newborns showed a variation of <1 cm. The small and large for gestational age detection rates were 2.9% and 4.3%, respectively. Stunting affected 6.5% of all newborns and wasting, 1.5%, with a predominance in girls and in full-term pregnancies; both conditions were present in 0.4% of the sample. Conclusions: Newborns from Ribeirão Preto, when compared to the Intergrowth-21 standard, are heavier, longer, and have a larger head circumference until they reach full-term.

Resumo Objetivos: Determinar os percentis 3, 50 e 97 de peso, comprimento e perímetro cefálico de recém-nascidos da Coorte BRISA Ribeirão Preto, segundo sexo e idade gestacional, e comparar com o padrão Intergrowth-21st; b) Estimar os fenótipos pequeno para idade gestacional (< percentil 3), grande para idade gestacional (> percentil 97), stunting (comprimento < percentil 3) e waisting (índice de massa corporal < percentil 3). Método: Estudo observacional de uma coorte de 7.702 recém-nascidos entre 01/01 e 31/12/2010 na cidade de Ribeirão Preto, SP, Brasil. Os percentis 3, 50 e 97 para as medidas antropométricas foram determinados com regressão polinomial fracionária. Resultados: A diferença de peso entre Ribeirão Preto e Intergrowth-21st foi pequena, mais acentuada nos recém-nascidos pré-termo (diferença média entre as duas populações foi de + 266 gramas); para os recém-nascidos a termo a diferença média foi de + 66 gramas e para os pós-termo de -113 gramas. Para comprimento, a variação média foi sempre < 1 cm; enquanto que para perímetro cefálico os recém-nascidos pré-termo apresentaram variação > 1 cm e os recém-nascidos a termo e pós-termo tiveram variação < 1 cm. As taxas de detecção de pequeno e grande para idade gestacional foram 2,9% e 4,3%, respectivamente. Stunting afetou 6,5% de todos os recém-nascidos e waisting 1,5%, com predomínio em meninas e em gestações a termo; ambas as condições estavam presentes em 0,4% da amostra. Conclusões: Os recém-nascidos de Ribeirão Preto, quando comparados com o padrão Intergrowth-21st, apresentam-se mais pesados, mais longos e com maior circunferência craniana até chegarem a termo.

Evaluation of the INTERGROWTH-21st project newborn standard for neonatal phenotypes and neonatal morbidity and mortality.

INTRODUCTION: The use of local references or standard for neonatal studies still requires their validation through indicators of morbidity and mortality. OBJECTIVE: evaluate the performance of the INTERGROWTH-21st Project (IG-21) standard and a commonly used Argentinian reference (Urquia) by examining the differences in the frequency of growth phenotypes, and the associated neonatal morbidity and mortality. METHODS: Retrospective cohort study of all singleton live-births from Sarda Maternity Hospital (Buenos Aires, Argentina) between 33 and 42 gestational age, using information obtained from a Perinatal Surveillance System (Agustina) dataset between 1996-2001 (n = 25948). Phenotypes small- and large-for-gestational age, stunting and waisting and a composite of neonatal morbidity/mortality (CNMM) were contrasted between the IG-21 standard and Urquia reference. RESULTS: the Urquia 3rd centile value was lower than IG-21 before 37 weeks, but then it surpassed IG-21 until term. Among Sarda , 2.3%, 5.9% and 8.9 were <3rd, <10th and >97th centile, respectively, under the IG-21 standard, while 3.7%, 10.1% and 8.4% were <3rd, <10th and >97th centile, respectively, under the Urquia reference. Stunting and waisting were 16.1% and 0.9%, respectively under IG-21. The IG-21 detection rates of CNMM showed that 28.5%, 19.6% and 8.5% occurred among weight<3rd,<10th and >97th centile, respectively, while 21.8%, 14.2% and 8.0%  occurred among <3rd, <10th and >97th centile under the Urquia criteria. Newborn weight <3rd,<10th and >97th  centile under IG-21 showed higher neonatal CNMM risk compared with Urquia reference. CONCLUSIONS: The IG-21 standard identified a higher risk of neonatal morbidity and mortality than the Urquia reference.

Introducción: El uso de referencias locales o estándares para estudios neonatales aún requiere su validación a través de indicadores de morbilidad y mortalidad. Objetivo: Comparar la capacidad predictiva del estándar INTERGROWTH-21st (IG-21st) y una referencia argentina (Urquia) mediante los fenotipos de crecimiento fetal y morbi-mortalidad neonatales. Métodos: Estudio de cohorte retrospectivo de recién nacidos vivos entre 33 y 42 semanas del Hospital Materno-Infantil Ramón Sarda (Buenos Aires, Argentina), entre 1996-2001 (n = 25948). Los fenotipos pequeños (PEG) y grandes para la edad gestacional, acortado y emaciado y un índice compuesto de morbilidad / mortalidad neonatal (CNMM) se contrastaron entre IG-21st y la referencia Urquia. Resultados: El 3er percentil del peso al nacer de Urquia fue menor que el de IG-21st antes de las 37 semanas; 2.3%, 5.9% y 8.9 de los RN fueron <3o, <10° y > 97° percentil, respectivamente, bajo el estándar IG-21st, mientras que 3,7%, 10,1% y 8,4% fueron <3 °, <10 ° y> 97 ° percentil, respectivamente, bajo la referencia Urquia. Acortados fueron 16.1% y emaciados 0.9%, bajo IG-21st. CNMM bajo IG-21st fueron 28.5%, 19.6% y 8.5% en peso<3o, <10º y >97º percentil, respectivamente, mientras que 21.8%, 14.2% y 8.0% ocurrieron en peso< 3°, <10° y > 97° percentil bajo Urquia. Acortados fueron 17.3% y emaciados 18.3%. Los RN <3er°, <10° y > 97° percentil bajo IG-21st mostraron mayor riesgo de CNMM en comparación con la referencia Urquia. Conclusiones: El estándar IG-21st identificó mayor riesgo de morbilidad y mortalidad que la referencia Urquia.

Placental measurements and their association with birth weight in a Brazilian cohort.

INTRODUCTION: Epidemiological studies have shown associations between placental measurements and perinatal and later life outcomes. OBJECTIVES: To report placental measurements and evaluate their association with birth weight in a Brazilian birth cohort. METHODS: Retrospective cohort study with 958 mothers, placentas, and newborns delivered at the Ribeirão Preto Medical School Hospital, Universidade de São Paulo, Brazil, in 2010 and 2011. The information was collected from interviews, medical records, and pathology reports. The placental measurements were: weight, largest and smallest diameters, eccentricity, thickness, shape, area, and birth weight/placental weight and placental weight/birth weight ratios. We analyzed the associations between birth weight and placental measurements using multiple linear regression. RESULTS: Placental weight alone accounted for 48% of birth weight variability (p < 0.001), whereas placental measurements combined (placental weight, largest and smallest diameters, and thickness) were responsible for 50% (p < 0.001). When adjusted for maternal and neonatal characteristics, placental measurements explained 74% of birth weight variability (p < 0.001). CONCLUSION: Placental measurements are powerful independent predictors of birth weight. Placental weight is the most predictive of them, followed by the smallest diameter.

Comparison of birth weight, length, and head circumference between the BRISA-RP and Intergrowth-21st cohorts.

OBJECTIVES: (a) To determine the 3rd, 50th, and 97th percentiles of weight, length, and head circumference of newborns from the Ribeirão Preto BRISA cohort, according to gender and gestational age, and compare them with the Intergrowth-21st standard; (b) To estimate the small for gestational age (<3rd percentile), large for gestational age (>97th percentile), stunting (length<3rd percentile), and wasting (body mass index<3rd percentile). METHODS: Observational study of a cohort of 7702 newborns between 01/01/2010 and 12/31/2010 in the city of Ribeirão Preto, SP, Brazil. The 3rd, 50th, and 97th percentiles were determined for the anthropometric measurements using fractional polynomial regression. RESULTS: The weight difference between Ribeirão Preto and Intergrowth-21st was small, being more pronounced in preterm infants (mean difference between the two populations of +266g); for full-term newborns, there was a mean difference of +66g, and for post-term infants, of -113g. For length, the mean variation was always <1cm; whereas for head circumference, preterm newborns showed a variation >1cm, and full-term and post-term newborns showed a variation of <1cm. The small and large for gestational age detection rates were 2.9% and 4.3%, respectively. Stunting affected 6.5% of all newborns and wasting, 1.5%, with a predominance in girls and in full-term pregnancies; both conditions were present in 0.4% of the sample. CONCLUSIONS: Newborns from Ribeirão Preto, when compared to the Intergrowth-21 standard, are heavier, longer, and have a larger head circumference until they reach full-term.

Placental measurements and their association with birth weight in a Brazilian cohort / Medidas placentárias e sua associação com o peso ao nascer em uma coorte brasileira

ABSTRACT: Introduction: Epidemiological studies have shown associations between placental measurements and perinatal and later life outcomes. Objectives: To report placental measurements and evaluate their association with birth weight in a Brazilian birth cohort. Methods: Retrospective cohort study with 958 mothers, placentas, and newborns delivered at the Ribeirão Preto Medical School Hospital, Universidade de São Paulo, Brazil, in 2010 and 2011. The information was collected from interviews, medical records, and pathology reports. The placental measurements were: weight, largest and smallest diameters, eccentricity, thickness, shape, area, and birth weight/placental weight and placental weight/birth weight ratios. We analyzed the associations between birth weight and placental measurements using multiple linear regression. Results: Placental weight alone accounted for 48% of birth weight variability (p < 0.001), whereas placental measurements combined (placental weight, largest and smallest diameters, and thickness) were responsible for 50% (p < 0.001). When adjusted for maternal and neonatal characteristics, placental measurements explained 74% of birth weight variability (p < 0.001). Conclusion: Placental measurements are powerful independent predictors of birth weight. Placental weight is the most predictive of them, followed by the smallest diameter.

RESUMO: Introdução: Estudos epidemiológicos demonstraram associações entre medidas placentárias, resultados perinatais e futuros. Objetivos: Descrever medidas placentárias e avaliar suas associações com peso ao nascer numa coorte de nascimentos brasileira. Metodologia: Estudo de coorte retrospectiva de 958 mães, placentas e recém-nascidos no Hospital das Clínicas da Faculdade de Medicina de Ribeirão Preto da Universidade de São Paulo, Brasil, em 2010 e 2011. As informações foram coletadas por entrevistas, prontuários médicos e laudos de patologia. As medidas placentárias foram: peso, diâmetros maior e menor, excentricidade, espessura, forma, área, relações peso ao nascer/ peso da placenta e peso da placenta/ peso ao nascer. As associações entre peso ao nascer e medidas placentárias foram examinadas por meio de regressão linear múltipla. Resultados: O peso da placenta foi responsável por 48% da variabilidade do peso ao nascer (p < 0,001), enquanto o conjunto de medidas placentárias (peso, diâmetros maior e menor e espessura) foi responsável por 50% (p < 0,001). Quando ajustadas pelas características maternas e neonatais, as medidas placentárias explicaram 74% da variabilidade do peso ao nascer (p < 0,001). Conclusão: medidas placentárias são preditores independentes do peso ao nascer. O peso placentário é o mais forte preditor dentre elas, seguido pelo diâmetro menor.