Razão peso/perímetro cefálico ao nascer na avaliação do crescimento fetal / Weight/head circumference ratio at birth for assessing fetal growth / La razón peso/perímetro cefálico al nacer para evaluar el crecimiento fetal

Objetivou-se utilizar a razão peso/perímetro cefálico ao nascer para avaliar o crescimento fetal. Foi realizado um estudo de coorte retrospectiva na Zona da Mata de Pernambuco, Brasil, com 915 crianças nascidas a termo. As medidas antropométricas da criança, assistência pré-natal, fumo durante a gestação, renda familiar, escolaridade e estado nutricional materno foram coletados nas primeiras 24 horas pós-parto. As crianças foram classificadas em proporcionais (razão peso/perímetro cefálico ≥ 0,90) e desproporcionais (< 0,90). Recém-nascidos de mães fumantes, com menor idade, sem consulta pré-natal, baixos IMC, altura e prega cutânea tricipital apresentaram menores médias da razão peso/perímetro cefálico. As médias do peso, comprimento, perímetros cefálico e torácico, circunferência braquial e prega cutânea tricipital foram menores entre as crianças classificadas como desproporcionais, por meio da razão peso/perímetro cefálico, ajustadas pelo sexo da criança. Conclui-se que a razão peso/perímetro cefálico e peso ao nascer são importantes indicadores do crescimento fetal.

The objective of this study was to use weight/head circumference ratio at birth to assess fetal growth. A retrospective cohort study was conducted in Zona da Mata, Pernambuco State, Brazil, with 915 term infants. Infants’ anthropometric measurements and data on prenatal care, smoking during pregnancy, family income, and maternal schooling and nutritional status were collected in the first 24 hours after birth. Infants were classified as proportionate (weight/head circumference ratio ≥ 0.90) versus disproportionate (< 0.90). Lower mean weight/head circumference ratio was associated with maternal smoking, younger age, inadequate prenatal care, and low BMI, height, and triceps skinfold thickness. Mean weight, length, head and chest circumference, arm circumference, and triceps skinfold thickness were lower among infants with disproportionate weight/head circumference ratio, independently of sex. In conclusion, weight/head circumference ratio and birth weight are important indicators of fetal growth.

El objetivo era usar el peso/perímetro cefálico al nacer para evaluar el crecimiento fetal. Se realizó un estudio de cohorte retrospectivo en Pernambuco Zona Mata con 915 niños recién nacidos. Las medidas antropométricas del niño, cuidado prenatal, fumar durante el embarazo, ingresos familiares, educación y estado nutricional de la madre se recogieron durante las primeras 24 horas después del parto. Los niños fueron clasificados en: proporcionados (peso/perímetro cefálico ≥ 0,90) y desproporcionados (< 0,90). Los recién nacidos de madres fumadoras con una menor edad, sin atención prenatal, bajo índice de masa corporal, altura y el espesor del pliegue cutáneo tricipital tuvieron promedios más bajos de peso/perímetro cefálico. La media de peso, talla, circunferencia de la cabeza y el pecho, circunferencia del brazo y el espesor del pliegue cutáneo tricipital fueron menores entre los niños clasificados como desproporcionados en peso/perímetro cefálico, sin independencia del sexo del niño. Se concluye que el peso/perímetro cefálico y el peso al nacer es un indicador importante del crecimiento fetal.

A ultrassonografia rotineira em pré-natal de baixo risco colabora com a diminuição das mortalidades maternas e neonatais / Does routine ultrasound in low risk pregnancy collaborate with the reduction of maternal and neonatal mortality

Esta revisão sistemática teve como objetivo avaliar se a realização da ultrassonografia (US) de rotina em gestações de baixo risco colabora com a diminuição da mortalidade materna e neonatal. Foi realizada uma revisão criteriosa da literatura dos últimos 20 anos, analisamos 121 estudos e deu-se preferência às revisões e aos ensaios clínicos randomizados, sendo esses estudos classificados segundo os níveis de evidência da Associação Médica Brasileira. Resultados: A US precoce possibilita melhor datação da gestação, evitando pós-datismo e induções desnecessárias, diagnostica gestações múltiplas com estabelecimento da corionicidade, e em lugares e casos em que a interrupção da gestação é permitida, diminui a mortalidade perinatal. A US morfológica do primeiro e segundo trimestres tem boa sensibilidade para detectar anomalias fetais, e o morfológico de segundo trimestre mostrou-se com razoável relação custo-benefício. A US após 24 semanas não demonstrou nenhum benefício claro para a mãe ou para o feto, a exceção da avaliação da maturidade placentária que parece reduzir a mortalidade perinatal. Conclusões: O tema continua controverso, necessitando de mais estudos que avaliem seu benefício em longo prazo. Como os estudos demonstram maior benefício antes de 24 semanas, algumas sociedades recomendam a realização de 2 exames: um ao redor de 12 semanas e o morfológico de segundo trimestre.

This systematic review aimed to assess whether the implementation of ultrasound (US) in routine low-risk pregnancies collaborates with decreasing maternal and neonatal mortality. We conducted a careful review of the literature of the last 20 years and analyzed 121 studies, and preference was given to the reviews and randomized clinical trials. These studies were classified according to the levels of evidence from the Brazilian Medical Association. Results: The early US allows: early dating of pregnancy avoiding post-term pregnancy and unnecessary inductions, diagnosis of multiple pregnancies and the establishment of chorionicity and reduce perinatal mortality in places and circumstances in which termination of pregnancy is allowed. The first and second trimester US screening have good sensitivity for detecting fetal abnormalities, and the second trimester US proved to be a reasonable cost-benefit analysis. The US after 24 weeks showed no clear benefit to the mother or the fetus, except for the evaluation of placental maturity that seems to reduce perinatal mortality. Conclusions: The issue remains controversial, requiring further studies to evaluate its long-term benefit. As the studies show more benefit before 24 weeks, some guidelines recommend performing 2 tests: 1 around 12 weeks and the second trimester screening.

Influence of intrauterine and extrauterine growth on neurodevelopmental outcome of monozygotic twins

There have been indications that intrauterine and early extrauterine growth can influence childhood mental and motor function. The objective of the present study was to evaluate the influence of intrauterine growth restriction and early extrauterine head growth on the neurodevelopmental outcome of monozygotic twins. Thirty-six monozygous twin pairs were evaluated at the corrected age of 12 to 42 months. Intrauterine growth restriction was quantified using the fetal growth ratio. The effects of birth weight ratio, head circumference at birth and current head circumference on mental and motor outcomes were estimated using mixed-effect linear regression models. Separate estimates of the between (interpair) and within (intrapair) effects of each measure on development were thus obtained. Neurodevelopment was assessed with the Bayley Scales of Infant Development, 2nd edition, by a psychologist blind to the exposure. A standardized neurological examination was performed by a neuropediatrician who was unaware of the exposures under investigation. After adjustment, birth weight ratio and head circumference at birth were not associated with motor or mental outcomes. Current head circumference was associated with mental but not with motor outcomes. Only the intrapair twin effect was significant. An increase of 1 cm in current head circumference of one twin compared with the other was associated with 3.2 points higher in Mental Developmental Index (95 percentCI = 1.06-5.32; P < 0.03). Thus, no effect of intrauterine growth was found on cognition and only postnatal head growth was associated with cognition. This effect was not shared by the co-twin.

Relación entre los niveles de ácido todo trans-retinoico en sangre de cordón umbilical y medidas antropométricas del recién nacido / Retinoic acid levels in the serum of blood from umbilical cord and their relation to anthropometric measures in newborn

Antecedentes: La vitamina A, principalmente en su forma de ácido todo trans-retinoico, desempeña una función de vital importancia durante el desarrollo gestacional en todos los tejidos y órganos del cuerpo. Objetivo: Determinar los niveles de ácido retinoico en el suero de sangre de cordón umbilical y relacionarlos con el peso/edad gestacional del recién nacido y el consumo materno de vitamina A, conjuntamente con variables socio-económicas y nutricionales. Método: Estudio descriptivo de corte transversal, analizando un total de 62 neonatos y sus madres, provenientes de las maternidades de los Hospitales San José y Barros Luco-Trudeau, Santiago de Chile. Resultados: En la población en estudio se observó una relación directa entre el peso/edad gestacional del neonato y el consumo materno de vitamina A, pero no con los niveles de esa vitamina en el suero de sangre de cordón umbilical. Se encontró que el consumo medio de vitamina A en las embarazadas fue sólo de 2298 +/- 1416,8 Ul, siendo la dosis recomendada por OMS de 8000 Ul. Conclusión: Existe asociación entre la ingesta de vitamina A y el estado nutricional materno en relación con el peso/edad gestacional del neonato. Debido a que los requerimientos nutricionales del feto están privilegiados por sobre los maternos, no se observaron diferencias en las características antropométricas del neonato asociadas a la ingesta materna de vitamina A.

Background: Vitamin A, mainly in their form of retinoic acid, it carries out a function of vital importance during the gestational development, in all the tissues and organs of the body. Objective: To evaluate the levels of retinoic acid in the serum of blood from umbilical cord and to relate them with the weight/gestational age ratio of the newborns and the maternal intake of vitamin A, jointly with socioeconomic and nutritional variables. Method: A descriptive study of traverse court, in the maternities of the Hospitals San José and Barros Luco-Trudeau of Santiago, Chile, studying a total of 62 cases. Results: In the population in study a direct relationship was observed between the newborn ratio weight/gestational age and the maternal consumption of vitamin A, but no relationship was found among the same weight/gestational age ratio and the levels of this vitamin in the serum of blood of umbilical cord. On the other hand, it was found that the average consumption of vitamin A in the maternities it was of 2298 +/- 1416.8 IU, being the dose recommended by WHO for pregnant of 8000 IU, therefore, the whole population in study had a faulty consumption of vitamin A. Conclusion: Exists association among the intake of vitamin A and the maternal nutritional state with the weight/gestational age ratio of the newborn and the concentration of trans-retinoic acid in the umbilical cord. Because the nutritional requirements of the fetus are privileged over the maternal ones, differences were not observed in the newborn anthropometries features associated to the maternal vitamin A intake.