| 1. |
- Maesel, A, et al.
(författare)
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Fetal cerebral blood flow velocity during labor and the early neonatal period
- 1994
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Ingår i: Ultrasound in Obstetrics & Gynecology. - : Wiley. - 1469-0705 .- 0960-7692. ; 4:5, s. 372-376
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Tidskriftsartikel (refereegranskat)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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| 2. |
- Sladkevicius, Povilas, et al.
(författare)
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Blood flow velocity in the uterine and ovarian arteries during menstruation
- 1994
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Ingår i: Ultrasound in Obstetrics & Gynecology. - : Wiley. - 1469-0705 .- 0960-7692. ; 4:5, s. 421-427
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Tidskriftsartikel (refereegranskat)abstract
- Eleven healthy women with regular menstrual cycles were examined with a combination of two-dimensional real-time ultrasound and color and spectral Doppler techniques on the 7th day after follicular rupture, and on the 1st, 2nd, 3rd and 4th days of menstrual bleeding. Both uterine arteries, arteries in the stroma and hila of both ovaries, in the wall of the largest follicle of the non-dominant ovary and in the wall of the corpus luteum were examined with the Doppler technique. The pulsatility index (PI) and the time-averaged maximum velocity were calculated. In the uterine arteries, the PI was highest on the first day of menstrual bleeding (median PI 3.2 for the dominant and 3.0 for the non-dominant uterine artery), after which it decreased to its lowest values on the second day (median PI 2.1 and 1.8, respectively) and third day (median PI 2.2 and 2.1, respectively). The time-averaged maximum velocity reached its highest value on the second and third days of menstruation. The corpus luteum was still visible on the first day of menstrual bleeding in all women, and on the second day in five. It was indistinguishable on the third and fourth days of menstruation in all women. In the dominant ovary, the time-averaged maximum velocity of flow in the arteries in the ovarian hilum decreased during menstrual bleeding and was lower during menstruation than in the preceding luteal phase. In the non-dominant ovary, neither the PI nor the time-averaged maximum velocity manifested any consistent changes during the period studied. We conclude that substantial changes in PI and time-averaged maximum velocity occur in the uterine arteries and in the arteries of the dominant ovary during menstruation.
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| 3. |
- Sladkevicius, Povilas, et al.
(författare)
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Blood flow velocity in the uterine and ovarian arteries during the normal menstrual cycle
- 1993
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Ingår i: Ultrasound in Obstetrics & Gynecology. - : Wiley. - 1469-0705 .- 0960-7692. ; 3:3, s. 199-208
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Tidskriftsartikel (refereegranskat)abstract
- Twelve healthy women with regular menstrual cycles were examined with a combination of two-dimensional real-time ultrasound and color and spectral Doppler techniques on cycle days 4 and 8 and daily from cycle day 12 until follicular rupture, then days + 1, +2, +5, +7 and +12 after follicular rupture. The uterine and subendometrial arteries, arteries in the ovarian stroma and hilum, in the wall of the largest follicle of each ovary, and in the wall of the corpus luteum were examined. The pulsatility index and the time-averaged maximum velocity were calculated. In the uterine arteries the pulsatility index was highest on day + 2, after which it decreased successively to its lowest value, whereas the time-averaged maximum velocity reached its highest value on day + 12. Similar changes were observed in the subendometrial arteries. In the non-dominant ovary, neither the pulsatility index nor the time-averaged maximum velocity manifested any consistent changes during the cycle. In the dominant ovary, the time-averaged maximum velocity increased and the pulsatility index decreased after follicular rupture, being significantly higher and lower, respectively, in the luteal than in the follicular phase. These changes were seen in the ovarian hilum, stroma and follicular wall, but were most obvious in the wall of the dominant follicle and of the corpus luteum. We conclude that the blood circulation in the uterus and in the dominant ovary changes considerably during the menstrual cycle, whereas that in the non-dominant ovary shows no unequivocal changes.
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