THE EFFECTS OF FETAL BLOOD-SAMPLING AND PLACENTAL PUNCTURE ON UMBILICAL ARTERY AND FETAL ARTERIAL VESSELS BLOOD-FLOW VELOCITY WAVE-FORMS

This study was performed to investigate whether fetal blood sampling a nd/or transplacental puncture are associated with changes of blood flo w velocity waveforms in umbilical artery and fetal circulation. The pu lsatility index (PI) was measured from umbilical artery, thoracic desc ending aorta, renal artery, and middle cerebral artery immediately bef ore and after fetal blood sampling (n=28) or third trimester amniocent esis (n=32). No significant changes in PI values were evidenced after amniocentesis performed either transamniotically (n=21) or transplacen tally (n=11). Fetal blood sampling induced a significant decrease of P I values in all the vessels investigated. However, in presence of a tr ansplacental procedure (n=15) the amplitude of the decrease of PI in u mbilical artery was significantly higher than after a transamniotic pr ocedure (n=13), while no differences were evidenced in the other vesse ls tested. These findings indicate that umbilical cord puncture at the time of fetal blood sampling is associated with a decrease in PI in u mbilical artery and several peripheral arterial vessels. The isolated placental puncture does not induce Doppler-detectable hemodynamic effe cts, while in conjunction with cord needling, it increases the amplitu de of the effects in umbilical artery.