Fetal Doppler Flow Research Articles

Uterine and fetal Doppler flow changes after misoprostol and oxytocin therapy for induction of labor in post-term pregnancies

Objectives: To compare the effect of misoprostol vs. oxytocin on blood flow in uteroplacental circulation during labor induction. Methods: Ninety-one women with indications for induction of labor were assigned to receive either misoprostol 50 μg per vagina every 4 h as needed or intravenous oxytocin by means of a randomization table generated by computer. Doppler velocimetry of umbilical, uterine and arcuate arteries was performed immediately before and 2–3 h after administration of misoprostol or oxytocin. Pulsatility index (PI), resistance index (RI) and systolic/diastolic (S/D) ratios were measured for these arteries. The SAS system was used to perform statistical analysis. Results: There were no significant changes of PI, RI and S/D ratios in umbilical arteries during misoprostol and oxytocin inductions. Vaginal application of misoprostol significantly increased PI, RI and S/D ratios in arcuate arteries and S/D ratio in uterine arteries. Conclusions: Our results indicate that intravaginal misoprostol administration increases uteroplacental resistance but probably does not substantially affect placental perfusion.

The effect of betamethasone on fetal biophysical activities and Doppler velocimetry of umbilical and middle cerebral arteries

Preliminary reports suggest that antenatal steroid administration may confound the assessment of fetal well-being by suppressing biophysical activities, consequently drug-induced effects could prompt unwarranted delivery of premature fetuses. The purpose of this study was to examine the effect of antenatal betamethasone administration on fetal biophysical activities and Doppler flow indices of the umbilical and middle cerebral circulation. Forty women at risk of premature delivery between 27-32 weeks gestation (mean 30.2 weeks) received two consecutive doses of intramuscular betamethasone, 24 hours apart. Ultrasonographic observations of fetal behavior for 30 minute periods and Doppler examination of the umbilical and cerebral arteries were performed prior to (0 hours), 48 hours after, and 96 hours after administration of the first dose. To account for fetal circadian rhythms and maternal prandial status, all examinations were carefully timed and performed between 1-4 pm. Analysis of Variance, chi-square test and Fisher's Exact test were used for statistical analysis, as appropriate. Nine patients were excluded from analysis due to delivery prior to completion of all examinations. Number of breathing episodes as well as total breathing time at 48 hours decreased by 83.0% (p<0.01) and 90.4% (p<0.01), respectively, at 48 hours in comparison to baseline. Fetal limb and trunk movements decreased by 53.2% (p<0.01) and 48.6% (p<0.01), respectively. Amniotic fluid volume and fetal tone were normal in all patients. At 48 hours, 14 of 31 fetuses and 4 of 31 fetuses had a biophysical profile score of 6/8 and 4/8, respectively, in comparison to 0 of 31 and 0 of 31 at 0 hours (p<0.05 and p<0.001, respectively). All parameters returned to baseline values at 96 h. Pulsatility indices of umbilical and middle cerebral arteries remained unchanged at 48 hours and 96 hours (p=NS). Betamethasone induces a profound, albeit transient, suppression of fetal breathing, limb and trunk movements, resulting in decreased biophysical profile scores. Awareness of this drug-induced effect might prevent unnecessary iatrogenic delivery of preterm fetuses.

Effect of Local Prostaglandin E2 on Uterine and Fetal Doppler Flow in Pregnancy-Induced Hypertension

Objectives: To evaluate the effects of vaginal and intracervical administration of prostaglandin E2 (PGE2) on the uterine, umbilical, and fetal blood flow in hypertensive pregnancies.Methods: Thirty-two women with pregnancy-induced hypertension undergoing cervical ripening for preinduction of labor were randomized to receive either 2.0 mg of PGE2 gel vaginally (n = 12), 0.5 mg of PGE2 gel intracervically (n = 10), or placebo gel vaginally (n = 10). The pulsatility index (PI) and resistance index (RI) in uterine arteries, umbilical artery, and fetal middle cerebral artery were calculated before and 30 and 60 min after administration of PGE2 or placebo.Results: Placebo gel caused no changes in any one flow variable. Because the vaginal and intracervical mode of administration of PGE2 caused similar changes in flow, these groups were combined. PGE2 increased (P < 0.0001) impedance to flow in uterine arteries 30 min (9.7 ± 2.8%, mean ± SE) and 60 min (20.5 ± 4.8%) after application. In contrast, impedance to flow tended to decrease in fetal cerebral arteries 30 min (8.1 ± 4.0%, NS) and 60 min (11.5 ± 3.5%, P < 0.004) later. No changes were seen, following PGE2 use, in umbilical blood flow. No clear-cut relationships could be found between changes in blood flow and uterine contractility, as assessed by external tochography.Conclusion: In hypertensive pregnancies, cervical ripening with PGE2 gel leads to increase in uterine vascular resistance, and to decrease in fetal middle cerebral artery resistance.

Fetal Renal Artery and Umbilical Artery Doppler Flow and Fetal Urine Output

The object of this study was to determine if a correlation exists between the resistance index (RI) of the umbilical artery, the RI of the fetal renal artery, and hourly urine output by fetuses of normal pregnancies. Doppler flow study of the fetal renal artery and the umbilical artery was performed in 110 fetuses between 19 and 40 weeks' gestation. Color and pulse wave Doppler was used to obtain the flow velocity waveforms. The RI of the flow velocity waveforms was calculated. Fetal bladder volume was calculated by transverse, anteroposterior, and longitudinal diameters obtained from coronal and transverse sonographic images of the fetal urinary bladder. The difference in bladder volume at 30-minute intervals was used to determine hourly urine output. Gestational age has a positive linear association with fetal urine output (P < 0.01). The RI of the fetal renal artery has a negative linear association with gestational age (P < 0.05). The RI of the umbilical artery decreased with an increase in gestation age (P < 0.01). There was a significant correlation between the RI of the umbilical artery (P < 0.01) and the fetal renal artery (P < 0.05) and hourly urine output by the fetus. The RI of the fetal renal artery decreased with gestational age. Hourly urine output of the fetus increased with gestational age. The RI of the umbilical artery and the fetal renal artery had a significant correlation with fetal urine output.

Prenatal diagnosis of cerebellar hemorrhage: Medicolegal implications

Perinatal brain damage and compromised long-term neurologic outcome have been a topic of major concern and continuing debate. Until recently the occurrence of fetal brain injury was attributed to intrapartum events. However, evidence continues to accumulate that neurologic damage can occur during fetal life unrelated to intrapartum events. We report a case of massive cerebellar hemorrhage of unknown cause diagnosed by ultrasonography at 36 weeks of gestation, after decreased fetal movements. Fetal heart rate pattern and Doppler flow study of cerebral arteries are correlated with neuropathologic findings, and the medicolegal aspects of this condition are discussed. Perinatal brain damage and compromised long-term neurologic outcome have been a topic of major concern and continuing debate. Until recently the occurrence of fetal brain injury was attributed to intrapartum events. However, evidence continues to accumulate that neurologic damage can occur during fetal life unrelated to intrapartum events. We report a case of massive cerebellar hemorrhage of unknown cause diagnosed by ultrasonography at 36 weeks of gestation, after decreased fetal movements. Fetal heart rate pattern and Doppler flow study of cerebral arteries are correlated with neuropathologic findings, and the medicolegal aspects of this condition are discussed.

Prenatal diagnosis of cerebellar hemorrhage: Medicolegal implications

Perinatal brain damage and compromised long-term neurologic outcome have been a topic of major concern and continuing debate. Until recently the occurrence of fetal brain injury was attributed to intrapartum events. However, evidence continues to accumulate that neurologic damage can occur during fetal life unrelated to intrapartum events. We report a case of massive cerebellar hemorrhage of unknown cause diagnosed by ultrasonography at 36 weeks of gestation, after decreased fetal movements. Fetal heart rate pattern and Doppler flow study of cerebral arteries are correlated with neuropathologic findings, and the medicolegal aspects of this condition are discussed. (AM J OBSTET GYNECOL 1994;170:1392-5.)

Single Dose of Pindolol in Normotensive Pregnancy: The Lack of Changes in Hemodynamics in Spite of Effective Beta-Receptor Binding

Objective: To evaluate the absorption, placental transfer, receptor occupancy, and acute hemodynamic effects of a single peroral dose of pindolol in healthy term pregnancy.Methods: Ten pregnant healthy women admitted for cesarean section at term after uneventful pregnancy received each 5 mg of pindolol perorally before operation. The acute hemodynamic responses were measured, and maternal and fetal circulations were assessed with color Doppler ultrasonography. Pindolol concentrations were measured with a sensitive radioreceptor binding assay, and the corresponding beta2-receptor occupancy was determined.Results: Mean maternal concentration of pindolol 1 h after ingestion was 9.4 ng/ml, and it rose to 14.6 ng/ml at the time of cesarean section; respective beta2-receptor occupancies were 91.8% and 98.8%. In the umbilical artery, pindolol concentration was 50% of the maternal concentration. A plasma concentration of 2.5 ng/ml yielded 90% beta2-receptor occupancy, which reflects the high potency of pindolol.Conclusion: Despite almost total blockade of beta2-receptors, no changes in maternal or fetal hemodynamics or Doppler flow velocity waveforms were observed.

Uterine and fetal Doppler flow changes after intravaginal prostaglandin E 2 therapy for cervical ripening

Nineteen patients received prostaglandin E2 as a 2.5 mg gel (seven cases), 3.3 mg chip (five cases), or 10 mg controlled-release pessary (seven cases) for preinduction cervical ripening. Blood flow velocities did not change significantly for the uterine arcuate artery, fetal aorta, and umbilical artery circulations after any of the treatments. In no case did systolic/diastolic ratios consistently elevate above baseline values.

317 Does fetal Doppler flow study have an effect on biophysical activity?

317 Does fetal Doppler flow study have an effect on biophysical activity?

Fetal cardiac Doppler flow studies in prenatal diagnosis of heart disease

The prenatal diagnosis of fetal cardiac disease has become increasingly accurate as the technology of ultrasound has improved. Although two-dimensional real-time ultrasound remains the primary method of diagnosis, Doppler blood flow velocity estimates can provide valuable pathophysiologic information to support the anatomic diagnosis. We present six cases in which Doppler studies contributed to the accuracy of the diagnosis of fetal heart disease, including tetralogy of Fallot, right and left ventricular hypoplasia, atrioventricular canal defect, double-outlet right ventricle, and pulmonic stenosis. Velocities in these cases are compared with those in normal fetuses. If Doppler flow velocities are not consistent with the observed morphologic changes, further observations are indicated. Inasmuch as most anatomical heart lesions result in altered flow patterns, Doppler investigations of intracardiac and extra cardiac flow should be a routine component of the fetal echocardiogram when structural abnormalities are found.

The relation between fetal heart rate and Doppler flow velocity waveform A/B ratio.

The relation between fetal heart rate and Doppler flow velocity waveform A/B ratio.

The use of Doppler ultrasound to assess intrauterine growth retardation in the fetus.

presented at the 34th Annual Meeting of the Society or Gynecologic Investigation, Atlanta, GA, March 18-2 I, 1987 82. Horensetin JH, Brar HS, Platt LD, et al: Cardiovascular evaluation of the post term fetus. Abstract presented at the 34th Annual Meeting of the Society for Gynecologic Investigation. Atlanta, GA, March 18-21, 1987 83. Rightmire DA, Campbell S: Fetal and maternal Doppler blood flow parameters in postterm pregnancies. Obstet Gym- col 69:891-894, 1987 84. Bracero L, Schulman H, Fleischer A, et al: Umbilical artery velocimetry in diabetes and pregnancy. Obster Gynecol 68:654-658, 1986 85. Friedman DM. Rutkowski M, Snyder JR, et al Doppler blood velocity waveforms in the umbilical artery as an indicator of fetal well being. JCU 13: 161.165, 1985 86. Trudinger BJ, Cook CM, Jones L, et al: A comparison of fetal heart rate monitoring and umbilical artery \haveforms in the recognition of fetal compromise. Br J Obstet Gynaeccll 93:171-175, 1986 87. Trudinger BJ, Cook CM, Giles WB. et al. ijmhilical artery flow velocity waveforms in high risk pregnancy. Ran- domized controlled trial. Lancet I: 188-190, 1987 88. Giles WB, Lingman G. Marsal K. et al: Fetal volume blood flow and umbilical artery flow velocity waveforms anal- ysis: A comparison. Br J Obstet Gynaecol 93:461-465. 1986 89. Griffin DR, Teague MJ, Tallet , et al: A combmed ultrasonic linear array scanner and pulsed Doppler velocmetry for estimation of blood flow in the foetus and adult abdomen. 11. Clinical evaluation. Ultrasound Med Biol 11:37-4 1, I985 90. Teague MJ. Wilson K, Battye CK. et al: A combined ultrasonic linear array scanner and pulsed Doppler velocimetry for the estimation of blood flow in the foetus and adult abdo- men. I. Technical aspects. Ultrasound Med Biol I I 27-36. 1985

Fetal and maternal doppler flow velocity waveforms in normal sheep pregnancy

Abnormalities in placental vascular resistance have been shown to have an important association with intrauterine growth retardation in both human and sheep pregnancies. In this study we have assessed impedance to blood flow through the ovine placental circulation by Doppler flow velocity waveform analysis. As gestation advanced from 66 to 136 days, a significant decrease in impedance to flow was observed in both umbilical and maternal placental arteries. The greatest decrease in impedance was observed between 66 and log days' gestation in umbilical arteries and between 66 and 80 days' gestation in maternal placental arteries. In these normal pregnancies, no significant correlations could be found between Doppler flow velocity waveform analyses and fetal or placental growth. We conclude that Doppler flow velocity waveform analysis is a valuable and non-invasive method to assess impedance to blood flow through the placental circulation in pregnant sheep.