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WS15‐07Assessment of a formula using Doppler velocimetry to calculate fetal hemoglobin (Hb)
Author(s) -
Voto L. S.,
Mulki O. B.,
Zapaterio J. L.,
Falco A.,
Mathet E. R.,
Lede R. L.,
Margulies M.
Publication year - 2000
Publication title -
ultrasound in obstetrics and gynecology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.202
H-Index - 141
eISSN - 1469-0705
pISSN - 0960-7692
DOI - 10.1046/j.1469-0705.2000.00009-1-99.x
Subject(s) - medicine , fetus , umbilical cord , cord , doppler effect , blood flow , nuclear medicine , cardiology , pregnancy , surgery , anatomy , physics , genetics , astronomy , biology
Aim To assess agreement between fetal cord blood Hb concentration by Doppler velocimetry and a formula (Oepkes et al, Br J Obstet Gynaecol 1994; 101:680–4), and the actual Hb concentration by cord blood sampling. Material and methods A prospective cohort of 31 Rh isoimmunised fetuses undergoing Doppler cord blood velocity measurements within the 24 hs previous to cordocentesis or delivery was included. Mean aortic velocity at descent fetal aorta and maximum umbilical vein flow at intrahepatic portion were measured blindly by a single operator with pulsed Doppler and a 3.5 Mhz transducer. Cord Hb was the gold standard. Abnormality and normality were defined as a Hb level lower and higher, respectively, than the cut‐off point (<7, <8, <9, <10, <11 and <12 g/dL were tested). Likelihood ratio was also calculated. Results Interval between Doppler study and cordocentesis/delivery was 24–48 hs. Fetal blood sampling was performed by cordocentesis in 4 cases, following a C‐section in 24, and following vaginal delivery in 3.1 Distribution of cases according to results obtained ( n cases)Cut‐off point <7g <8g <9g <10g <11g <12gTrue+ 1 5 7 14 23 26 False+ 1 1 7 7 6 5 True– 29 25 15 7 2 0 False– 0 0 2 3 0 02 (abstract WS15‐07) Agreement at different cut‐off points in the diagnosis of abnormality and normality [point estimate (CI)]Cut‐off <7 <8 <9 <10 <11 <12Abn. 50(5–100) 83(36–99) 43(21–69) 58(37–77) 79(60–91) 84(66–94) Norm. 97(81–100) 96(78–100) 62(41–80) 41(17–67) 25(4–64) 0(0–54) LR 30(2.3–129.8) 26(4.2–132.4) 2.7(1.2–5.9) 1.6(1–3) 1.3(1–2.4) 1(0.9–2)Conclusion An acceptable agreement was found. Further population‐based studies are required to corroborate its clinical significance.