UTERINE AND FETAL BLOOD FLOWS IN PREGNANCIES COMPLICATED BY PRETERM LABOR

Flow velocity waveforms were recorded by Doppler ultrasonography from the uterine arteries, umbilical artery, thoracic descending aorta, ren al artery and middle cerebral artery in fetuses of 57 pregnancies comp licated by preterm labor with intact membranes. The uterine artery res istance index was significantly increased in patients with preterm lab or when compared to reference limits for gestation, but no relationshi p was found with the time interval between Doppler recordings and deli very. The group of fetuses (n = 15) delivered within 48 h from entry t o the study showed significantly reduced pulsatility index values from the middle cerebral artery when compared to fetuses delivered later o r to the normal reference limits for gestation. No significant differe nces were found in the other vessels studied. In conclusion preterm de livery is associated with alterations in fetal cerebral waveforms and knowledge of these changes may prove useful in the evaluation of patie nts with preterm labor.