Obstetrics and Gynaecology · Haematology

Intrauterine Red-Cell Transfusion Volume calculator

Enter the published formula inputs below to calculate and interpret this score.

Clinical inputs

Estimated fetal weight

Allowed range: 0–10 kg

Ultrasound weight in grams. The paper prints no weight cap. This form accepts 1 g through 10000 g, and that span is only the limit of this form and is not a printed cap.

Fetal hematocrit

Allowed range: 1–80 %

Enter hematocrit in percent. The paper does not print a hematocrit cap. The entry limits are not printed caps.

Target hematocrit

Allowed range: 1–80 %

Enter hematocrit in percent. The paper does not print a hematocrit cap. The entry limits are not printed caps.

Donor hematocrit

Allowed range: 1–90 %

Hematocrit of the transfused red cells, in percent. The entry limits are not printed caps.

Result

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Primary source

Mandelbrot L, Daffos F, Forestier F, MacAleese J, Descombey D. Assessment of fetal blood volume for computer-assisted management of in utero transfusion. Fetal Ther. DOI: 10.1159/000263335. PMID: 3257068. Fetoplacental volume in mL is 1.046 + fetal weight in g × 0.14. Transfused volume is that volume times (final concentration minus initial concentration) divided by the transfused concentration. Concentration is the hematocrit, entered here in percent for the fetus, the target, and the donor unit. The paper does not print a maximum volume or a weight cap. A numeric bound on this form is only the limit of this form and is not a printed cap. The volume has to be verified against the local protocol. (1988)

Scope: Intravascular intrauterine transfusion when the ultrasound fetal weight and the three hematocrits are known. The same ratio applies if every hematocrit is entered in percent.

Last reviewed 2026-10-17

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Professional use only

For qualified clinicians. Independently verify inputs, calculations, source guidance, and applicability before any clinical action. This calculator does not replace clinical judgment.

Source: Mandelbrot L, Daffos F, Forestier F, MacAleese J, Descombey D. Assessment of fetal blood volume for computer-assisted management of in utero transfusion. Fetal Ther. DOI: 10.1159/000263335. PMID: 3257068. Fetoplacental volume in mL is 1.046 + fetal weight in g × 0.14. Transfused volume is that volume times (final concentration minus initial concentration) divided by the transfused concentration. Concentration is the hematocrit, entered here in percent for the fetus, the target, and the donor unit. The paper does not print a maximum volume or a weight cap. A numeric bound on this form is only the limit of this form and is not a printed cap. The volume has to be verified against the local protocol. (1988)

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Clinical inputs

Estimated fetal weightAccepted range: 1 to 10000
Fetal hematocrit (%)Accepted range: 1 to 80
Target hematocrit (%)Accepted range: 1 to 80
Donor hematocrit (%)Accepted range: 1 to 90

Primary source

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