HDFN II

Question 1

After anti-D which other antibodies are able to cause HDFN

Answer 1

Anti-c
anti-K

Question 2

Compare between the ABO and Rh hemolytic disease of the fetus

Answer 2

ABO Rh
Jaundice mil to mod mod to svr
Edema NO Mil to svr
ABO/D type O- mother D-neg mother
DAT Neg and weak + Pos
Antibody Anti-A or B/ both Anti-D
anaemia Mild mod to severe
reticulocyte mild increase greatly increased
Nucleated RBC mild increase greatly increase
Bililubin mild increase. mod to svr
peaks 24 to 48 hr
after birth

second roll is ABO the third is RH
MOD IS MODERATE while svr is severe

Question 2

Ways how prediction of HDFN is achieved

Answer 2

1. Martenal History
2. Antibody Titration

Question 3

Explain martenal histroty as a way of predicting HDFN

Answer 3

For a woman with a history of HDFN secondary to anti-D, a subsequent
D-positive fetus has a much greater chance of being affected. A history of a previously
affected infant can be useful in predicting the prognosis for future pregnancies.

Question 3

Explain antibody titration as a way of predicting HDFN

Answer 3

Antibody titration is a laboratory method used to measure the concentration of specific antibodies in a blood sample. In the context of predicting Hemolytic Disease of the Fetus and Newborn (HDFN), antibody titration helps assess the risk and severity of the disease.
How Antibody Titration Works:
Sample Collection: Blood is drawn from the mother.
Serial Dilution: The blood sample is diluted in a series of steps, creating multiple dilutions.
Testing: Each dilution is tested to see if it can cause agglutination (clumping) of red blood cells that have the specific antigen.
Determination of Titre: The highest dilution that still causes agglutination is noted. This dilution is called the antibody titre.

Question 4

explain amniocentesis

Answer 4

One measure of red cell destruction and the severity of HDFN is the level of bilirubin
pigment found in amniotic fluid. Amniotic fluid is obtained by amniocentesis, or the
insertion of a needle through the mother’s abdominal wall and uterus and extraction of
fluid from the amniotic sac. The aspirated fluid is scanned spectrophotometrically from
350 to 700 nm. The change in optical density (ΔOD) above the baseline at 450 nm is a
measure of the bilirubin pigments

Question 4

explain ultrasound techniue in the detection of HDFN

Answer 4

Fetal anemia caused by hemolysis of red cells during pregnancy can be detected by ultrasound
techniques, specifically color Doppler ultrasonography, which can be used to
measure blood flow velocity.5 An increased cardiac output and a decreased blood viscosity
are associated with fetal anemia. Evaluation of the peak systolic velocity in the middle
cerebral artery of the fetus with color Doppler ultrasonography can determine the severity
of fetal anemia without invasive procedures

Doppler technology is primarily used in ultrasound to measure blood flow

Question 5

Explain cordocentesis in the detection of HDFN

Answer 5

Cordocentesis is a useful diagnostic and therapeutic technique. Using an ultrasoundguided
needle, the umbilical vein is punctured near the point of placental insertion. A
fetal blood sample is aspirated, which can be used to measure hematologic (hemoglobin/
hematocrit) or biochemical (bilirubin) variables directly. Before testing, the specimen must
be determined to be fetal and not maternal in origin.