Blood flow Doppler velocimetry measured during active labor.

PURPOSE: To evaluate blood flow Doppler velocimetry during the first and second stages of active labor. METHODS: A prospective observational study was performed. Patients at term (37-42 weeks gestation), with normal fetal heart rate tracing patterns (categorized as category I) were examined during the first and second stages of labor. The sonographic parameters that were measured included the blood flow resistance of the maternal uterine artery (UtA) and umbilical artery (UA). Wilcoxon-matched pair test was used for the comparison of flows between the first and the second stages of labor. RESULTS: UtA and UA Doppler velocimetry measurements were obtained from 31 parturients. The left (LT) and right (RT) UtA pulsatility index (PI) was lower in the second stage of labor as compared with the first stage. However, only the LT side reached a statistically significant difference (0.88 ± 0.32 and 0.73 ± 0.18; P = 0.005). Compared with the first stage of labor, UA PI was significantly higher during the second stage of labor (0.72 ± 0.17 vs. 0.84 ± 0.33; respectively, P = 0.05). CONCLUSION: Significant blood flow resistance changes in maternal as well as in fetal blood vessels occur during the second stage as compared with the first stage of active labor.

Third-trimester abnormal uterine artery Doppler findings are associated with adverse pregnancy outcomes.

OBJECTIVES: To evaluate the association between third-trimester abnormal uterine artery Doppler findings and pregnancy outcomes. METHODS: A prospective study was designed, including 198 consecutive singleton pregnancies between 27 and 41 weeks' gestation. In the study population, 144 had normal uterine artery Doppler waveforms, 37 had unilateral pathologic waveforms, and 17 had bilateral pathologic waveforms. Eighty patients had intrauterine growth restriction (IUGR), preeclampsia toxemia, or both, and 118 had no complications and served as a control group. The uterine artery Doppler waveform was considered abnormal when a notch or pulsatility index above the 90th percentile was noted. RESULTS: In patients with bilateral pathologic uterine artery Doppler waveforms, the rates of cesarean delivery, small-for-gestational-age (SGA) neonates, preterm delivery, and low Apgar scores were increased compared to patients with normal or pathologic unilateral waveforms (P = .009; P > .001; P = .007; P > .001, respectively). The incidence rates for SGA neonates, cesarean delivery, and preterm delivery were significantly higher among patients without IUGR or preeclampsia toxemia when associated with pathologic bilateral waveforms in comparison to normal waveforms (P = .01 for all). A bilateral pathologic waveform was found to be an independent risk factor for cesarean delivery and SGA neonates. The incidence rates for SGA neonates and preterm delivery were significantly higher among patients with IUGR and/or preeclampsia toxemia when associated with bilateral abnormalities in comparison to normal waveforms (P = .01 for both). CONCLUSIONS: Third-trimester abnormal uterine artery Doppler findings are associated with worse perinatal outcomes among patients both with and without pregnancy complications.