Fetal and maternal blood volumes in shed human placentae: discrepant results comparing morphometry to haemoglobin content

Barker, G.; Cunliffe, N.; D'Souza, S W; Donnai, P.; Boyd, Robert D.

doi:10.1016/0143-4004(88)90036-7

Cited by 15 publications

(8 citation statements)

References 17 publications

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“…These results compare favourably with the 35.3% obtained in a morphometric study of placentas sampled during caesarean section. 40 They also suggest that the proportion of blood within the placenta is not reduced by chronic hypoperfusion or fetal growth restriction: only placental perfusion appears to be reduced. This result could be explained by the absence of a significant change in the anatomy of the placenta during IUGR, but only by a modification of the perfusion of blood within the placenta.…”

Section: Discussionmentioning

confidence: 99%

SPIO‐enhanced magnetic resonance imaging study of placental perfusion in a rat model of intrauterine growth restriction

Deloison

Siauve

Aimot

et al. 2012

BJOG

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Objective To assess placental perfusion with magnetic resonance imaging (MRI) and superparamagnetic iron oxide (SPIO) in a rat model of intrauterine growth restriction (IUGR).Design Experimental animal study.Setting The study complied with US National Institutes of Health recommendations for animal care.Population Thirty-two rats at day 16 of gestation underwent surgical ligation of the left uterine vessel to induce IUGR.Methods Eighteen rats were examined by MRI 3 days later, after bolus injection of ferucarbotran.Main outcome measure Signal intensities were measured in the maternal left ventricle and in the placentas of the two horns. Quantitative microcirculation parameters were calculated and compared between the placentas of the two horns.Results Fifty-four kinetic curves of placental perfusion were obtained in 11 rats. The mean placental blood flow was significantly lower in the ligated horns than in the normal horns (108.1 versus 159.4 ml/minute/100 ml, p = 0.0004). The mean fractional volume of the maternal vascular placental compartment did not differ significantly between the pathological (42.8%) and normal placentas (39.2%).Conclusions Placental perfusion, including changes during experimental IUGR, can be measured in rats by using MRI with SPIO. These findings could have implications for human studies of placental microcirculation and for the management of disorders related to placental dysfunction.

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Section: Discussionmentioning

confidence: 99%

SPIO‐enhanced magnetic resonance imaging study of placental perfusion in a rat model of intrauterine growth restriction

Deloison

Siauve

Aimot

et al. 2012

BJOG

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show abstract

“…The discrepancy between values obtained using 5lCr-EDTA and 14C-inulin requires further investigation, but if 5lCr-EDTA gives as good a measure of placental ECV as it appears to do in the sheep [4], it can be calculated, using the value of 20% for the combined maternal and fetal blood volumes obtained for placentae treated similarly [1] to those here, that the interstitial volume of the human placenta accessible from both cir culations is between 55 and 60%. The mech anisms controlling this large, rather constant interstitial volume remain obscure.…”

Section: Discussionmentioning

confidence: 99%

“…To deter mine how much blood was left in the tissues after these experiments, the total haemoglobin content of weighed fragments of closed-circuit perfused, incu bated, and fresh placenta was also measured using homogenized tissue and the cyanmethaemoglobin method [1].…”

Section: Comparison O F F 'Cr-edta and '4c-inulin Spaces As Measured mentioning

confidence: 99%

Extracellular Volume of the Human Placenta in vitro

Lear

Barker²,

Sibley³

et al. 1989

Neonatology

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The extracellular volume of fresh and perfused human placenta has been measured in two sets of experiments. In the first set fragments of placenta which had been dually perfused for either 45 or 110 min as well as fragments from unperfused areas of the same placenta were incubated for 4 h in Earle’s bicarbonate buffer containing ⁵¹Cr-EDTA as an extracellular marker. The ⁵¹Cr-EDTA space, as a proportion of wet weight, was 76.5 ± (SE) 1.4 (n = 11) and 79.4 ± 1.8% (n = 6) for the short and long perfusions, respectively; these did not significantly differ from each other or from the values for the equivalent unperfused placenta: 75.2 ± 1.0 (n = 11) and 77.7 ± 0.9% (n = 6). In the second set of experiments ⁵¹Cr-EDTA and ¹⁴C-inulin were perfused through the maternal and fetal circulations of the placental lobules for 1 2, or 4 h, and simultaneously unperfused fragments from the same placenta were incubated with the markers for 1 2, or 4 h. The ⁵¹Cr-EDTA space was found to be significantly higher than the ¹⁴C-inulin space in both perfusion and incubation determinations. Irrespective of the marker, the incubation spaces were unaltered with time and were significantly higher than the perfusion spaces at all three time points. However, the difference decreased with the length of perfusion, so that by 4 h it was less than 10%. (At 4 h incubation the ⁵¹Cr-EDTA space was 76.2 ± 0.9% and the perfusion space 67.4 ± 1.1 %, n = 6; the ¹⁴C-inulin incubation space was 60.9 ± 2.2% and the perfusion space 52.5 ± 2.6%, n = 5.) As there was no evidence of increasing placental permeability with time, as judged by clearance of creatinine, it was concluded that the placental extracellular volume is large irrespective of the method of measurement.

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“…Maternal and fetal venous whole blood Hb levels were measured, as was the percentage of fetal Hb in placental extract and fetal blood. These values allowed calculation of maternal fetal vascular volumes for unperfused and perfused placenta (Barker, Cunliffe, Bardsley, D'Souza, Donnai & Boyd, 1987), the latter representing the residual unperfused vascular volume. Creatinine concentration in maternal arterial perfusate [M] The results show that a large proportion of the vascular space on both maternal and fetal sides remained unperfused, and that this was not reduced by longer perfusion.…”

Section: Development Of Inward Rectification Inmentioning

confidence: 99%

Proceedings of the Physiological Society, 17‐18 July 1987, Oxford Meeting: Poster Communications

1987

The Journal of Physiology

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Fetal and maternal blood volumes in shed human placentae: discrepant results comparing morphometry to haemoglobin content

Cited by 15 publications

References 17 publications

SPIO‐enhanced magnetic resonance imaging study of placental perfusion in a rat model of intrauterine growth restriction

SPIO‐enhanced magnetic resonance imaging study of placental perfusion in a rat model of intrauterine growth restriction

Extracellular Volume of the Human Placenta in vitro

Proceedings of the Physiological Society, 17‐18 July 1987, Oxford Meeting: Poster Communications

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