Correlação entre Testes para Avaliação da Vitalidade Fetal, pH da Artéria Umbilical e os Resultados Neonatais em Gestações de Alto Risco Correlation between the Assessment of Fetal Well-being, Umbilical Artery pH at Birth and the Neonatal Results in High-risk Pregnancies

Abstract

Objetivos: analisar a relação entre valores de pH no nascimento, testes de vitalidade fetal e resultados neonatais. Métodos: foram incluídas 1346 pacientes com gestação de alto risco atendidas no Setor de Vitalidade Fetal do HCFMUSP. Para estudo do bem-estar fetal foram realizados exames de cardiotocografia, perfil biofísico fetal e índice de líquido amniótico. Após o parto foram obtidos os seguintes parâmetros dos recém-nascidos: idade gestacional no parto, sexo e peso dos recém-nascidos, índices de Apgar de 1º e 5º minutos, pH da artéria umbilical no nascimento e a ocorrência de óbito neonatal. Para estudo destes resultados neonatais, os casos foram divididos em quatro grupos: G1 (pH ou = 7,20). Resultados: a cardiotocografia anormal relacionou-se com valores de pH inferiores a 7,20 (p = 0,001). Resultados anormais do perfil biofísico fetal (Purpose: to analyze the relationship between the values of pH at birth, fetal surveillance examinatios and neonatal results. Methods: one thousand, three hundred and forty-six high-risk pregnancies were evaluated at the Fetal Surveillance Unit. The assessment of fetal well-being included cardiotocography, fetal biophysical profile and amniotic fluid index. After birth, the perinatal results (gestational age at birth, birth weight, Apgar scores at 1st and 5th minutes, umbilical cord pH at birth) were collected. To study the results, the patients were divided into four groups: G1 (pH or = 7.20). Results: the abnormal patterns of cardiotocography were associated with pH at birth inferior to 7.20 (p = 0.001). Abnormal results of the fetal biophysical profile (<=4) were related to decrease in pH values at birth (p<0.001). The adverse neonatal outcomes were associated with acidosis at birth, and they were selected to be analyzed by the logistic regression model, showing that the odds ratio of each adverse neonatal outcome increases significantly when the values of pH at birth decrease. Conclusions: significant correlation was found between the values of pH at birth and adverse neonatal results, providing the possibility to estimate the risk of neonatal complications according to the pH values at birth.

Keywords

• Anoxia perinatal
• Cardiotocografia
• Perfil biofísico fetal
• Óbito neonatal
• Fetal distress
• Cardiotocography
• Biophysical profile scores
• Neonatal death