Myers S A, Ferguson R
Department of Obstetrics and Gynecology, Mount Sinai Hospital Medical Center, Chicago, Illinois.
Obstet Gynecol. 1989 Sep;74(3 Pt 1):325-31.
In order to describe the relationship between fetal death rate and impaired fetal growth, we examined over 850,000 births in Illinois between 1980-1984 (using the state computer data file) and assessed the mean/modal birth weights at each gestational age and the relationship between birth weight and fetal death rate at each gestational age. We were interested in the following questions: 1) Is the relationship between impaired fetal growth and fetal death rate the same at each gestational age? and 2) What birth weight would result in a quadrupling of the fetal death rate at each gestational age? Using exponential regression analysis, we determined for each gestational age the fetal death rate at the modal birth weight and similarly, the birth weight expected to result in a quadrupling of the fetal death rate. As gestational age advanced, the birth weight percentile resulting in the constant outcome also increased (second percentile at 25 weeks; 17th percentile at 42 weeks). We also compared these data with similar data from Denver. The findings indicate the following: 1) Fetal death rate increases exponentially as birth weight decreases at each gestational age; 2) the birth weight percentile that results in a constant outcome is not consistent at each gestational age; and 3) if assessment of risk is to be inferred based on the relationship between birth weight and gestational age, the tenth percentile (whether Denver, Illinois, or elsewhere) does not predict stillbirth accurately. The implications point to the use of outcome-oriented risk assessments to predict fetal death when examining the relationship between birth weight and gestational age.
为了描述胎儿死亡率与胎儿生长受限之间的关系，我们调查了1980年至1984年伊利诺伊州超过850,000例出生情况（使用该州计算机数据文件），评估了每个孕周的平均/众数出生体重以及每个孕周出生体重与胎儿死亡率之间的关系。我们关注以下问题：1）胎儿生长受限与胎儿死亡率之间的关系在每个孕周是否相同？以及2）每个孕周出生体重达到多少会使胎儿死亡率增加四倍？通过指数回归分析，我们确定了每个孕周众数出生体重时的胎儿死亡率，同样也确定了预期会使胎儿死亡率增加四倍的出生体重。随着孕周增加，导致相同结果的出生体重百分位数也增加（25周时为第2百分位数；42周时为第17百分位数）。我们还将这些数据与丹佛的类似数据进行了比较。研究结果表明：1）在每个孕周，胎儿死亡率随着出生体重的降低呈指数增加；2）导致相同结果的出生体重百分位数在每个孕周并不一致；3）如果要根据出生体重与孕周之间的关系推断风险评估，第十百分位数（无论是丹佛、伊利诺伊州还是其他地方）并不能准确预测死产情况。这些结果表明，在研究出生体重与孕周之间的关系时，应使用以结果为导向的风险评估来预测胎儿死亡。
