Patterson R M, Prihoda T J, Gibbs C E, Wood R C
Obstet Gynecol. 1986 Oct;68(4):459-63.
Birth weight-gestational age tables are convenient methods for the neonatal evaluation of intrauterine growth, however, the limits of acceptable birth weight for gestational age are controversial. The purpose of this study was to identify the birth weight percentiles that accurately predicted poor perinatal outcome from 28 through 41 weeks' gestational age. In a homogeneous population of 44,811 patients, the birth weight percentile that predicted poor perinatal outcome varied with gestational age. The birth weight percentile that predicted normal outcome in 80% of normal patients declined from the 55th percentile at 28 to 29 weeks to the 24th percentile at 34 to 35 weeks. From 28 through 35 weeks' gestational age, possibly owing to the confounding effects of prematurity, patients classified as normal by birth weight criteria still had a significant risk of poor outcome. After 36 weeks' gestational age, poor perinatal outcome occurred in 3.9% of patients and tended to occur at the extremes of birth weight. Classification by birth weights approximating the tenth and 90th percentiles identified a population in which the majority of the poor perinatal outcome occurred. However, poor outcome occurred in only 10% of patients with birth weights below the tenth or above the 90th percentiles. Among those with birth weights between the tenth and 90th percentiles, outcome was normal in 98%. Therefore, from 36 through 41 weeks' gestational age, the prevalence of poor perinatal outcome was low, and birth weight percentile was a weak predictor of outcome in the individual patient.
出生体重与孕周对照表是评估胎儿宫内生长情况的便捷方法，但孕周对应的可接受出生体重范围仍存在争议。本研究旨在确定能准确预测孕28至41周围产期不良结局的出生体重百分位数。在44,811例同质化患者中，预测围产期不良结局的出生体重百分位数随孕周变化。在80%正常患者中预测正常结局的出生体重百分位数从孕28至29周的第55百分位数降至孕34至35周的第24百分位数。孕28至35周，可能由于早产的混杂效应，按出生体重标准分类为正常的患者仍有显著的不良结局风险。孕36周后，3.9%的患者出现围产期不良结局，且往往发生在出生体重的极端值。按接近第10和第90百分位数的出生体重分类，可确定大多数围产期不良结局发生的人群。然而，出生体重低于第10百分位数或高于第90百分位数的患者中只有10%出现不良结局。出生体重在第10和第90百分位数之间的患者中，98%结局正常。因此，孕36至41周，围产期不良结局的发生率较低，出生体重百分位数对个体患者结局的预测能力较弱。
