Curva dos valores normais de peso fetal estimado por ultra-sonografia segundo a idade gestacional

Cadernos de Saúde Pública (Impact Factor: 0.89). 01/2000; DOI: 10.1590/S0102-311X2000000400026
Source: DOAJ

ABSTRACT Este trabalho teve por objetivo avaliar a evolução do peso fetal estimado em gestações normais de 20 a 42 semanas. Quanto ao desenho e métodos empregados na pesquisa, realizou-se estudo descritivo de um universo constituído por 2.874 gestantes normais da cidade de Campinas, efetuando-se exame ultra-sonográfico obstétrico de rotina com medida da biometria fetal e utilizando-se, para o cálculo do peso fetal, a fórmula de Hadlock et al. (1991). Calcularam-se os valores dos percentis 10, 50 e 90 do peso fetal, por idade gestacional, com construção de curva posteriormente alisada mediante ajuste polinomial de 2º grau. Como resultado, obteve-se que o valor do percentil 50 foi de 368 gramas na 20ª semana, 1.512 gramas na 30ª semana, atingindo 3.417 gramas na 42ª semana. Constatou-se ter havido ganho médio de 200 gramas de peso por semana, de 27 a 38 semanas, a partir de quando o incremento diminuiu. Concluiu-se que a disponibilidade de curva brasileira do peso fetal estimado normal permitirá o diagnóstico pré-natal de seus desvios pela ultra-sonografia.


Available from: Jose G Cecatti, Sep 21, 2014
  • [Show abstract] [Hide abstract]
    ABSTRACT: All gases are slightly soluble in water and radon is relatively soluble in groundwater. Concentrations from a few tens to hundreds of bequerels per liter of water can be found in most countries. After maternal ingestion of Rn-222 in raw water, it is transported by the blood and diffuses throughout the body including into the placenta. The short-lived alpha-particle emitting decay products from radon can thus reach an embryo/fetus. In the case of the embryo/fetus, it is of special interest to estimate the radiation dose because there is an early interval of pregnancy when the fetus is at the most risk for severe effects from radiation. In the very tiny early embryos, there are two important factors to consider. The very small size of the embryo should yield a commensurately small target for alpha-particle hits, but conversely, alpha-particle damage to nuclear DNA may have major consequences. For the purposes of dosimetric calculations in the developing embryo and fetus, both the maternal and the fetal placental blood supply at different time points were estimated. Our calculations relied on the available published data for these and for fetal weights as starting points. The Rn-222 accumulating in the various compartments following the ingestion of 100 Bq dissolved in water was estimated and the dose as a function of time is based on the pharmacokinetic model we developed. The clearance half times for the various tissues in the mother are based on some historic published human data for radon. If we assume an average of 0.6 liters of raw tap water at a concentration of 100 Bq per liter are consumed per day, the calculated total dose to the fetus over the term of the pregnancy is about 250 mu Sv or 25% of the normal background radiation dose.
  • [Show abstract] [Hide abstract]
    ABSTRACT: Objectives-The purpose of this study was to establish reference charts of fetal biometric parameters measured by 2-dimensional sonography in a large Brazilian population. Methods-A cross-sectional retrospective study was conducted including 31,476 low-risk singleton pregnancies between 18 and 38 weeks' gestation. The following fetal parameters were measured: biparietal diameter, head circumference, abdominal circumference, femur length, and estimated fetal weight. To assess the correlation between the fetal biometric parameters and gestational age, polynomial regression models were created, with adjustments made by the determination coefficient (R-2). Results-The means +/- SDs of the biparietal diameter, head circumference, abdominal circumference, femur length, and estimated fetal weight measurements at 18 and 38 weeks were 4.2 +/- 2.34 and 9.1 +/- 4.0 cm, 15.3 +/- 7.56 and 32.3 +/- 11.75 cm, 13.3 +/- 10.42 and 33.4 +/- 20.06 cm, 2.8 +/- 2.17 and 7.2 +/- 3.58 cm, and 256.34 +/- 34.03 and 3169.55 +/- 416.93 g, respectively. Strong correlations were observed between all fetal biomettic parameters and gestational age, best represented by second-degree equations, with R-2 values of 0.95, 0.96, 0.95, 0.95, and 0.95 for biparietal diameter, head circumference, abdominal circumference, femur length, and estimated fetal weight. Conclusions-Fetal biometric parameters were determined for a large Brazilian population, and they may serve as reference values in cases with a high risk of intrauterine growth disorders.
    Journal of ultrasound in medicine: official journal of the American Institute of Ultrasound in Medicine 07/2014; 33(7):1185-91. DOI:10.7863/ultra.33.7.1185 · 1.53 Impact Factor
  • Source