Tei index for prenatal diagnosis of acute fetal hypoxia due to intermittent umbilical cord occlusion in an animal model.
OBJECTIVE
To study the effectiveness of the pulsatility index for veins of ductus venosus (DV-PIV) and the Tei index in a prospective assessment of fetal hypoxic-ischemic brain damage in a near-term ovine fetus model with intermittent umbilical cord occlusion (UCO).


METHODS
Twelve fetal sheep were studied with umbilical cord occlusion performed in the experimental group animals by complete inflation of an occluder cuff for 90 s, every 30 min for approximately 2.5 h. Fetal arterial blood was sampled at 5 min before the first umbilical cord occlusions, approximately 60 s of the first umbilical cord occlusions, and 3 min after each occlusion for blood gas, pH, neuron-specific enolase (NSE) and S100B. Doppler measurements and Doppler echocardiographic examinations were performed 5 min before the first umbilical cord occlusions and 3 min after each successive occlusion.


RESULTS
In experimental group animals, UCO caused a large decline in arterial PaO(2) (to approximately 7.70 mmHg, p < 0.01), a modest decline in pH (to approximately 7.24, p < 0.01), and a modest rise in PaCO(2) (to approximately 53.31 mmHg, p < 0.01), with a return more or less to baseline after occluder release. and there was significant change as compared with the control animals (all p < 0.01) with cumulative changes in responses to repetitive cord occlusions. The DV-PIV waveforms, right ventricle (RV) and LV Tei indices, the serum levels of NSE and S100B increased with cord occlusions (all p < 0.05), and were significantly higher than the control animals (all p < 0.05) with a cumulative changes in responses to repetitive cord occlusions. RV and LV Tei indices were significantly correlated with PaO(2) (r = - 0.684, p < 0.01 and r = - 0.725, p < 0.01), PaCO(2) (r = 0.682, p < 0.01 and r = 0.780, p < 0.01), pH (r = - 0.538, p < 0.01 and r = - 0.681, p < 0.01), NSE (r = 0.653, p < 0.01 and r = 0.687, p < 0.01), and S100B (r = 0.606, p < 0.01 and r = 0.640, p < 0.01). Significant but weaker correlations were also present between DV-PIV and the parameters considered.


CONCLUSIONS
Umbilical cord occlusion during the latter part of the pregnancy, enough to cause significant hypoxemia and acidosis, results in a significant increase of DV-PIV, RV and LV Tei indices, and the serum levels of NSE and S100B. There was a strong correlation between the RV and LV Tei indices and blood gas, pH, and NSE, S100B with hypoxia. Therefore, the Tei index might be an easy and useful quantitative parameter for assessing fetal hypoxic ischemia.
Guorong
Lv
L
Department of Ultrasound, The Second Affiliated Hospital of Fujian Medical University, Quanzhou, Fujian, China. lgr_fe@sina.com
Shaozheng
He
H
Zhenghua
Wang
W
Boyi
Li
L
Qiuyue
Chen
C
Peng
Jin
J
Ruiyuan
Su
S
D000208:Acute Disease; D000818:Animals; D001784:Blood Gas Analysis; D002545:Brain Ischemia / Q000150:complications* / Q000175:diagnosis*; D003251:Constriction, Pathologic; D004195:Disease Models, Animal; D015150:Echocardiography, Doppler; D005260:Female; D005312:Fetal Blood / Q000737:chemistry; D005311:Fetal Hypoxia / Q000097:blood / Q000175:diagnosis* / Q000209:etiology; D006305:Health Status Indicators; D009414:Nerve Growth Factors / Q000097:blood; D010751:Phosphopyruvate Hydratase / Q000097:blood; D011247:Pregnancy; D011296:Prenatal Diagnosis / Q000379:methods*; D064568:S100 Calcium Binding Protein beta Subunit; D009418:S100 Proteins / Q000097:blood; D012756:Sheep; D014470:Umbilical Cord / Q000473:pathology*; D016276:Ventricular Function
D009414:Nerve Growth Factors; D064568:S100 Calcium Binding Protein beta Subunit; D009418:S100 Proteins; D010751:Phosphopyruvate Hydratase