Francisco Rossana Pulcineli Vieira, Miyadahira Seizo, Zugaib Marcelo
Department of Obstetrics and Gynecology, University of São Paulo, São Paulo, Brazil.
Obstet Gynecol. 2006 May;107(5):1042-8. doi: 10.1097/01.AOG.0000209192.00890.3a.
To investigate arterial and venous blood flow in fetuses with absent or reversed end-diastolic flow in the umbilical arteries and to correlate the Doppler results with umbilical artery blood pH at birth to predict the probability of acidosis at birth.
Ninety-one fetuses from singleton pregnancies without fetal malformations with a diagnosis of absent or reversed end-diastolic flow in the umbilical arteries were prospectively studied. On the day of delivery, Doppler velocimetry of the umbilical arteries, middle cerebral artery, and ductus venosus was performed and the results were correlated with umbilical artery pH at birth at the following cutoff levels: pH < 7.20, < 7.15, < 7.10, and < 7.05. The association between fetal arterial and venous Doppler velocimetry and acidosis was then individually analyzed by the chi(2) and Fisher exact tests. The ability of these tests to predict the probability of acidosis at birth was estimated using a logistic regression model.
There was a negative correlation between pH at birth and umbilical artery pulsatility index (r = -0.39; P < .001) and pulsatility index for veins in the ductus venosus (r = -0.63; P < .001). Assessment of the fetal arterial circulation (middle cerebral artery) showed no statistical correlation with pH at birth. Using logistic regression analysis, probability curves were constructed for pH values less than 7.20 (odds ratio [OR] 8.03), less than 7.15 (OR 11.92), less than 7.10 (OR 12.16), and less than 7.05 (OR 8.20).
The pulsatility index for veins of the ductus venosus was related to pH at birth, demonstrating that the higher the ductus venosus pulsatility index for veins, the lower the pH at birth. Once the pulsatility index for veins in the ductus venosus is known, the probability of acidosis at birth can be estimated.
研究脐动脉舒张末期血流缺失或反向的胎儿的动脉和静脉血流情况，并将多普勒检查结果与出生时脐动脉血pH值相关联，以预测出生时酸中毒的可能性。
前瞻性研究了91例单胎妊娠、无胎儿畸形且诊断为脐动脉舒张末期血流缺失或反向的胎儿。在分娩当天，对脐动脉、大脑中动脉和静脉导管进行多普勒测速，并将结果与出生时脐动脉pH值在以下临界值水平进行关联：pH < 7.20、< 7.15、< 7.10和< 7.05。然后通过卡方检验和Fisher精确检验分别分析胎儿动脉和静脉多普勒测速与酸中毒之间的关联。使用逻辑回归模型评估这些检查预测出生时酸中毒可能性的能力。
出生时的pH值与脐动脉搏动指数（r = -0.39；P <.001）以及静脉导管中静脉的搏动指数（r = -0.63；P <.001）呈负相关。对胎儿动脉循环（大脑中动脉）的评估显示与出生时的pH值无统计学相关性。使用逻辑回归分析，构建了pH值小于7.20（优势比[OR] 8.03）、小于7.15（OR 11.92）、小于7.10（OR 12.16）和小于7.05（OR 8.20）的概率曲线。
静脉导管中静脉的搏动指数与出生时的pH值相关，表明静脉导管中静脉的搏动指数越高，出生时的pH值越低。一旦知道静脉导管中静脉的搏动指数，就可以估计出生时酸中毒的可能性。
