Fetal Blood Type and Rh Factor Monitoring

To diagnose, monitor, and treat Hemolytic Disease of the Fetus and Newborn (HDFN)

ABO HDFN and Non-ABO HDFN are compared and contrasted

Miscarriage, stillbirth, and early death

Because it is gendered

Tests used for the determination of fetomaternal hemorrhage are compared and contrasted

The RhIg dosage is calculated using a specific process

To be more inclusive and reflect the patients that are served.

Mom/Baby Studies

Performed early in the pregnancy

Test for weak D if there is an ABO/Rh discrepancy or the Anti-D is weakly positive

All pregnancies: Antepartum at 28 Weeks if one of the following occurs: miscarriage, abortion, trauma (fall or accident), or invasive procedure (examples: IUT, amniocentesis, repositioning). Within 72 hours of delivery if the baby is D pos or weak D pos or fetal Rh is unknown. Patient is not already sensitized to D antigen.

To determine if the antibody is IgG and clinically significant (capable of causing HDFN)

The routine prenatal and postpartum tests for HDFN consist of ABO/Rh typing, antibody screen, and antibody identification if indicated.

ABO HDFN has different lab findings but the same effect on the baby.

Non-ABO HDFN has different lab findings but the same effect on the baby.

The qualitative FMH screen is used to determine the presence of fetal red blood cells in the maternal circulation. It can only be used on Rh negative parents.

The Kleihauer-Betke/Flow Cytometry test is used to quantify the amount of fetomaternal hemorrhage in any Rh parent.

The number of RhIg vials is calculated based on the volume of Rh positive blood exposure to the mother.

≥8

more sensitive and will have different action levels

Change in optical density at 450nm is in Zone III or high Zone II of the Liliey graph, Cordocentesis hemoglobin is less than 10 g/dL, Fetal Hydrops is noted on ultrasound examination, Twin to Twin transfusion

Reasoning: Irradiated (freshly irradiated is best), Leukoreduced, Fresh (<5 days old or <7 facility dependent), O Neg (Parental blood can be used in case of high prevalence antibody), Antigen Compatible with Parent, Hgb S negative, Possible Modification: Washing or Supernatant removed

Risk of parental contamination, Wharton’s Jelly Cannot be blood type of record, Newborns in general Mixed field in ABO, Did the parent undergo IUT during pregnancy, Interference from Parental antibody

Typically acid elution or Lui Freeze/Thaw elution, Performed on baby's red blood cells, Test elution with antibody screen and panel, Add type specific cells if ABO incompatibility is suspected

The Rosette Test is used to detect fetal blood in the parent's blood sample.

The KB stain is not very precise, time-consuming, and can have staining issues. It may also result in confusion between fetal cells and lymphocytes. Additionally, if the parent has increased Hgb F levels, the test results may be falsely elevated.

RHIG administration works by blocking or hindering the immune response, clearing out RBCs instead of stimulating the immune system, and creating an immunostat response where the body thinks it has already made antibodies.

The dose of RHIG is calculated using the formula: (number of fetal cells / number of parent's cells) * 100 * 50 = fetal bleed volume. The fetal bleed volume is then divided by 30 and rounded up to the nearest whole number to determine the number of vials of RHIG to give.

The antibodies of concern in hemolytic disease of the fetus and newborn are Anti-A, Anti-B, Anti-A,B, Anti-D, Anti-c, Anti-E, and Anti-K (most significant after Rh).

Monitoring of anemia and high bilirubin levels in the newborn can be done through measuring total bilirubin levels and using bili-lights. If bilirubin levels exceed 25 mg/dl and bili-lights are not effective, an exchange transfusion may be required as a last resort.