Fetal brain venous return in complicated pregnancy

Objective. To estimate the fetal brain venous return in the complicated pregnancy. Methods. Blood flow waveforms (BFW) in jugular vein (JV) were recorded in 162 fetuses from 13 to 40 weeks of normal gestation and in 63 growth restricted fetuses. Peak velocity in ventricular systole (S), peak velocity in early diastole which corresponds to passive ventricular filling (D), peak velocity in atria contraction with active ventricular filling (A), mean velocity (TAV) were measured and pulsatility index (PIV=S-A/TAV), systolic to diastolic ratio (S/D) were calculated. Results. S, D, A, TAV in growth restricted fetuses were significantly greater and PIV, S/D were significantly lower than in normal fetuses after 36 weeks of gestation. Conclusions. The results demonstrate that there are neuroprotective reactions of fetal cerebral venous blood flow after 36 weeks of gestation.