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- Maesel, A, et al.
(author)
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Fetal cerebral blood flow velocity during labor and the early neonatal period
- 1994
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In: Ultrasound in Obstetrics & Gynecology. - : Wiley. - 1469-0705 .- 0960-7692. ; 4:5, s. 372-376
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Journal article (peer-reviewed)abstract
- This study was performed to elucidate circulatory changes in the fetal cerebral circulation during uncomplicated labor and in early neonatal life. Eighteen healthy term singleton fetuses were followed longitudinally during labor. Using the transabdominal approach, and the color Doppler technique, the middle cerebral artery was identified and Doppler flow velocity waveforms recorded between and during uterine contractions. Neonatal recordings were made by insonating the middle cerebral artery from the temporal region before and immediately after the cutting of the umbilical cord, and at 1 hour and 1 day after birth. The recorded Doppler signals were evaluated for pulsatility index, heart rate, peak systolic flow velocity, end-diastolic flow velocity and time-averaged maximum velocity. There was no change in the pulsatility index between and during contractions (1.39 +/- 0.36 and 1.40 +/- 0.39, respectively, mean +/- SD). A significant decrease in the pulsatility index compared to fetal values was seen 4 min after birth (1.06 +/- 0.30, p < 0.01). One hour after birth, the pulsatility index values increased significantly (1.52 +/- 0.25, p < 0.001), to fall again between I hour and 1 day after birth (0.95 +/- 0.26, p < 0.001). Mechanical compression of the skull, blood gas changes and a decrease in ductal shunting may all have contributed to these changes. The present study has shown physiological neonatal circulatory adaptation and onset of breathing to cause manifest changes in cerebral blood flow velocity.
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- Maesel, A, et al.
(author)
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Mode of delivery and perinatal cerebral blood flow
- 1996
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In: Early Human Development. - 1872-6232. ; 44:3, s. 85-179
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Journal article (peer-reviewed)abstract
- OBJECTIVE: To ascertain whether the perinatal cerebral blood flow velocity differed between vaginally delivered appropriate for gestational age (vag. AGA) term babies, AGA babies delivered by Caesarean section (C.s. AGA), and small for gestational age (C.s. SGA) babies also delivered by Caesarean section. STUDY DESIGN: Forty-five babies were examined by Doppler ultrasound of the middle cerebral artery prior to and immediately after delivery, and at 1 h and 24 h after birth. The pulsatility index (PI) and time-averaged maximum velocity (TAMXV) were calculated. RESULTS: No differences in TAMXV were found between the vag. AGA and C.s. AGA groups at any of the four recordings. A significantly higher PI value was found in the C.s. AGA group 1 h after birth. The C.s. SGA group had lower PI values before and just after birth, but did not differ significantly from the C.s. AGA group at 1 h or 24 h after birth. CONCLUSIONS: The results suggest mode of delivery to have a transitory effect on cerebral vascular resistance in healthy term AGA babies. The C.s. SGA group differed in the initial recording just after birth, but later manifested similar blood flow velocities in middle cerebral artery as the C.s. AGA group.
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