Atypical ductus venosus blood flow pattern during a prolonged fetal heart rate deceleration in labor

Arteriovenous malformation of vein of Galen as a rare non-hypoxic cause of changes in fetal heart rate pattern during labor

The aim of this case report is to describe a rare non-hypoxic cause of pathological changes in fetal heart rate pattern during labor, and to determine management, including a description of important prenatal aspects when pathologic cardiotocographic recording is performed during labor. A fetus with rare arteriovenous malformation of the vein of Galen, which represents less than 1% of all intracranial arteriovenous malformations, was monitored by intrapartum external cardiotocography in the 37 + 5 gestational week. The baby was born by cesarean section because of signs of imminent intrauterine hypoxia on cardiotocography. However, metabolic acidosis was not confirmed in umbilical cord blood sampling. Despite intensive neonatal care management, the newborn died 31 h after delivery because of progressive cardiac decompensation, hypotension and multi-organ failure. Precise diagnosis of the abovementioned pathology, a pre-labor plan for delivery and postnatal prognosis assessment can significantly contribute to the avoidance of a misdiagnosis of fetal hypoxia and unnecessary operative delivery with marked medico-legal consequences.

Fetal circulatory variation in an acute incident causing bradycardia

Umbilical artery\vein, middle cerebral artery, and ductus venosus Doppler velocimetry were performed at 33 weeks of gestation in the settings of an intrauterine growth restricted fetus during a heart rate deceleration. Interestingly, we recorded a sudden onset redistribution of fetal blood flow with fetal bradycardia. Spontaneous normalization of waveforms was observed once fetal heart rate returned to normal. Our case provides evidence to circulatory variation of a human fetus resulting from an acute incident causing bradycardia.

Reproducibility of fetal ductus venosus blood flow velocity waveforms during first stage of labor

OBJECTIVES

Fetal ductus venosus (DV) blood flow velocity waveforms are significantly altered during contractions in first stage of labor. We have evaluated the reproducibility of these waveforms during and between contractions.

METHODS

90 women between 37th and 41st week of gestation were included in the study. The measurements of the DV were obtained by three different investigators during and between contractions. The pulsatility index for veins (PIV), peak velocity index for veins (PVIV), and fetal heart rate (FHR) were calculated offline. Furthermore, differences in PVIV (PVIVdiff) and PIV (PIVdiff) and a mean of FHR (FHRmean) were calculated. Statistical analysis was used to verify differences in the PIV, PVIV and FHR during and between contractions of each subgroup as well as for the PVIVdiff, PIVdiff and FHRmean between the subgroups.

RESULTS

Investigator 1 examined 49 patients (group 1); investigator 2, 17 patients (group 2) and investigator 3, 24 patients (group 3), respectively. In all subgroups, there was a significant difference for the PVIV and PIV during and between contractions, but not for FHR. There was a correlation between gestational age and PVIVdiff, PIVdiff and FHRmean as well as for maternal age and PVIVdiff and PIVdiff. PVIVdiff and PIVdiff showed significant differences in group 1 compared to groups 2 and 3 (p < 0.001), but not between groups 2 and 3.

CONCLUSIONS

Significant differences in the measurements in the three subgroups have been revealed, which may be due to different timing of measurement during the contraction. For future studies further standardization of the measurement protocol should be established.

Ductus venosus Doppler measurement during labor

OBJECTIVES

To assess ductus venosus (DV) indices during the first stage of labor and the effect of ruptured membranes, meconium stained liquor and epidural analgesia (EDA).

METHODS

Prospective cross-sectional study. Eighty-one women with low-risk singleton term pregnancies participated, 51 had normal labor (Group 1), and 30 experienced ruptured membranes and/or stained liquor (Group 2). Of the latter group 14 received EDA. The effect of various interventions and application of EDA on the ductus venosus index (DVI) and pulsatility index for veins (DV PIV) were tested.

RESULTS

The feasibility rate was 94%. A significant increase of DV indices (DVI, DV PIV) was found in group 2 (P<0.001 and P<0.0005, respectively). The A-velocity was also significantly lower in group 2 (P<0.02). A markedly significant increase of DV indices (P<0.0001) among participants receiving EDA was observed in group 2. The mean+/-SD indices were: 0.53+/-0.10 for the DVI and 0.68+/-0.14 for the DV PIV in those women. There was a significant positive correlation of DV indices with the duration of amniorrhea in group 2 (PIV: r=0.66; P<0.002; DVI: r=0.68; P<0.001).

CONCLUSIONS

Long-term amniorrhea seems to affect the fetal venous circulation reflected in increased DV waveform indices.

Uterine activity and ductus venosus flow velocity patterns during the first stage of labor

OBJECTIVE

To analyze the effects of uterine contractions on ductus venosus (DV) pulsatility during the first stage of labor.

METHODS

Twenty healthy women were examined. Measurements were taken at three stages of cervical dilatation (<4 cm, 4-7 cm and >or=8 cm) during and between contractions. Peak velocity during ventricular systole (S) and atrial contraction (A), pulsatility index for veins (DV PIV), ductus venosus index (DVI) and the S/A ratio were measured.

RESULTS

The DV was observed successfully in 16 cases. The mean S velocity did not change significantly (64 cm/s during and 65 cm/s between contractions). The mean A velocity decreased significantly from 35 cm/s measured between contractions to 29 cm/s during contractions (P<0.0001). The mean DV PIV and DVI were significantly higher during contractions (0.72 and 0.55) than between contractions (0.57 and 0.45) (P<0.0001). There were no significant differences in means between stages of cervical dilatation.

CONCLUSION

Significant differences during and between uterine contractions can be observed in DV pulsatility during normal labor.