Objective  To explore the relationship of fetal nucleated red blood cell counting and hemodynamics of umbilical arteries with chronic fetal distress

and provide experimental support to handle this clinic problem timely and rightly.   Methods  A total of 78 pregnant women

including 30 normal pregnant

18 acute fetal distress groups and 30 chronic fetal distress groups were enrolled in this study after the informed consent was signed and the protocol was approved by the Ethics Committee of our hospital. Fetal nucleated red blood cells were isolated from maternal peripheral blood with single density gradient centrifugation and then counted. Color Doppler blood flow visualize technology was used to defect the pulsatility indexes (PI)

resistance indexes (RI) and systolic/diastolic (S/D) ratio of fetal umbilical arteries. The results were compared among different groups. The sensitivity

speciality

diagnostic accuracy of the 2 methods

cell counting and ultrasonography

alone or combined together

were evaluated. Placenta change was verified by pathological method.   Results  The mean number of fetal nucleated red blood cells in maternal peripheral blood was 15.42±4.11

6.92±2.17

and 5.95±1.76 cells /6 ml respectively in chronic fetal distress group

acute fetal distress group and normal pregnant group. The cell numbers of chronic fetal distress group was markedly higher than the other 2 groups (P0.05). No difference was found between the acute fetal distress group and the normal control group (P0.05). In the chronic fetal distress group

umbilical artery S/D

PI and RI value was 3.27±0.66

1.12±0.15 and 0.71±0.07 respectively

which were higher than those of normal pregnant group (2.16±0.25

0.69±0.10 and 0.55±0.06 respectively

P0.05). The counting of fetal nucleated red blood cells in chronic fetal distress group had a positive linear correlation with its umbilical artery S/D and PI values

but no such correlation was found in the normal pregnant group. The sensitivity and diagnostic accuracy of combined 2 methods was higher than either method alone. The results of the 2 methods were verified by pathological observation on the placenta.   Conclusion  The numbers of fetal nucleated red blood cells in maternal blood and umbilical artery S/D are increased markedly in the fetal chronic distress groups. So the 2 values can be used as the markers of chronic fetal distress. Combining the 2 methods together will improve the sensitivity and diagnostic accuracy to predict and diagnose chronic fetal distress.