Flow velocity waveforms (FVWs) from the fetal umbilical artery were recorded from 2178 pregnant women over a 6-year period. All of them had an obstetric factor indicating increased risk of fetal compromise. A total of 6749 studies was recorded. The systolic diastolic (AB) ratio was measured and classified as normal ( 0 5 t h centile), elevated (9599th centile), high (>!Nth centile) or extreme (absent diastolic flow). The results of these studies have been related to subsequent fetal and neonatal outcome. An abnormal umbilical artery FVW was associated with shorter gestation and infants with lower birthweight, shorter length and lower ponderal index. There was a highly significant association between an abnormal FVW and the birth of an infant small for gestational age. The significance of the association increased with the increased abnormality of the umbilical artery FVW and this was independent of gestational age. Preterm infants associated with high or extreme AB ratios spent twice as long in the neonatal nursery than those with normal AB ratios. Analysis of 794 pregnancies studies serially indicated that an abnormal FVW in which the AB ratio was increasing, in contrast to a decreasing AB ratio, predicted a poor outcome for both size at birth and duration of neonatal intensive care. We conclude that in high risk pregnancy Doppler umbilical artery FVW studies predict the most compromised fetuses in terms of growth retardation and requirements for neonatal intensive care.For an investigativc method to be accepted as a
Trillium QuikQuant is a new precise, accurate and rapid flow cytometric kit method for the quantitation of FMH in both the antenatal and postpartum period.
Objective: To assess the potential for dose‐reduction of prophylactic anti‐D postpartum.
Design: Retrospective audit of fetomaternal haemorrhage (FMH) quantitation by flow cytometry.
Participants and setting: 5148 consecutive Rhesus D‐negative women aged 15–45 years who had FMH estimation by flow cytometry at a central laboratory in Western Australia in the 65 months between 1 August 1999 and 31 January 2005.
Main outcome measures: Quantitation of FMH volume for adequate prophylactic anti‐D administration in a timely fashion.
Results: 90.4% (4651/5148) of the women had an FMH volume of 1.0 mL or less of Rh D‐positive red cells, and 98.5% (5072/5148) had a volume of less than 2.5 mL. Only 0.4% of cases had an FMH volume of 6.0 mL or greater (range, 6.0–92.4 mL).
Conclusions: This large retrospective audit shows that a currently available dose of 250 IU (50 mg) of anti‐D would have been sufficient for 98.5% of the 5148 Rh D‐negative women. On the basis of this evidence, a reduction in the recommended routine postpartum dose of anti‐D from 625 IU to 250 IU when flow cytometric quantitation for FMH is available should be considered. Adopting such a strategy would ensure the ongoing provision of a valuable human blood product currently in limited supply.
Flow cytometry has been shown to be a more accurate and sensitive method than the Kleihauer-Betke test for the measurement of feto-maternal haemorrhage in Rh(D) incompatibility. This report describes the successful use of flow cytometry to detect and monitor the management of a massive transplacental haemorrhage (105 ml) of fetal Rh(D) positive cells in a Rh(D) negative woman. The report highlights the accuracy and reproducibility of the test and the stability of a blood sample when transferred 596 kilometres to a central testing facility.
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