Rahman F, Detti L, Ozcan T, Khan R, Manohar S, Mari G
Department of Obstetrics and Gynecology, King Faisal Hospital and Specialist Centre, Riyadh, Saudi Arabia.
Acta Obstet Gynecol Scand. 1998 Sep;77(8):804-7.
To assess the efficacy of a single measurement of amniotic fluid optical density deviation at 450 nanometers in predicting fetal anemia in Rhesus-alloimmunization before 27 weeks gestation.
In this cross-sectional study, fetal blood and amniotic fluid samples from 43 Rhesus-alloimmunized pregnancies at 18 to 26 weeks gestation were obtained under ultrasound guidance. Amniotic fluid samples were scanned by spectrophotometry for optic density at various wavelengths. Deviation at 450 nanometers was calculated between 550 and 365 nanometers. The fetuses were divided into three groups based on their hematocrit levels and the predictive efficacy of optic density zones for anemia was evaluated.
A high number of false positive and false negative results were observed when the delta-amniotic fluid optical density of fetuses at risk for anemia was plotted to the zones recently proposed to manage Rhesus-alloimmunized pregnancies.
These data confirm previous results that the diagnosis of fetal anemia in Rhesus-alloimmunized pregnancies before 27 weeks' gestation cannot be accurately made by a single measurement of amniotic fluid optical density at 450 nanometers.
评估妊娠27周前对恒河猴血型同种免疫孕妇单次测量450纳米羊水光密度偏差在预测胎儿贫血方面的疗效。
在这项横断面研究中，于超声引导下获取了43例妊娠18至26周的恒河猴血型同种免疫孕妇的胎儿血液和羊水样本。羊水样本通过分光光度法扫描不同波长下的光密度。计算450纳米处相对于550和365纳米处的偏差。根据胎儿血细胞比容水平将胎儿分为三组，并评估光密度区域对贫血的预测疗效。
当将有贫血风险胎儿的羊水光密度差值绘制成图并与最近提出的用于管理恒河猴血型同种免疫妊娠的区域进行对照时，观察到大量假阳性和假阴性结果。
这些数据证实了先前的结果，即在妊娠27周前，对恒河猴血型同种免疫孕妇的胎儿贫血诊断不能通过单次测量450纳米羊水光密度准确做出。
