MMSC 420 Exam 1 Latest 2026/2027
Complete Questions and Detailed Answers
| (Graded A+)
ABO antibodies - ANSWER✔✔ IgM antibodies that *have an IgG
component* and can cause HDFN
middle cerebral artery peak systolic volume (MCA-PSV) -
ANSWER✔✔using a doppler ultrasound to find the velocity of
blood flow through the cerebral artery of the fetus
-compare to a mean value for their gestational age
-having a velocity of 1.5x or higher the mean (MoM) indicates
anemia
homozygous - ANSWER✔✔cells that are used to screen a
maternal antibody titer have ____________________ expression of
antigens
-these cells have the strongest expression of antigen, so will
have the best chance to react with the maternal antibodies
maternal antibody elution titer - ANSWER✔✔if clinically
significant IgG antibody is present in mother, perform serial
dilutions of her serum and test it against homozygous cells
corresponding to the antigen multiple times throughout
pregnancy to monitor progression of antibody
-perform multiple times to see if antibody is increasing
(indicate risk of HDFN)
,-only test AHG phase so that you are only seeing IgG
antibodies
titer (maternal antibody elution titer) - ANSWER✔✔the
reciprocal of the most dilute maternal serum preparation that
is showing visible agglutination (1+)
-e.g. if the tube is 1:4, read it as 4
-*do not count w+*
-a titer of 16 is clinically significant
-for anti-K a titer of 8 is clinically significant
-a 2 fold increase in titer (goes up by 2 tubes) since the last
test is clinically significant
titer score (maternal antibody elution titer score) -
ANSWER✔✔every tube of maternal serum dilution that is
reactive is assigned a point value, and added together
- 4+= 12 points
- 3+= 10 points
- 2+= 8 points
- 1+= 5 points
- w+= 2 points (*weak positives are counted*)
-an increase in score of 10 since the last test is clinically
significant
-higher titer score indicates a stronger reacting antibody
(higher avidity)
, Rh immunoglobulin (RhIg/ RhoGAM) - ANSWER✔✔a
concentrate of IgG anti-D that is derived from pooled human
plasma
-is administered to protect non-immunized Rh negative
females from forming anti-D during pregnancy
-rhogam coats fetal D antigen that is found in maternal
circulation and destroys it before the mother's immune
system can form antibodies
rhogam candidate - ANSWER✔✔-prenatal administration: Rh
negative female that does not make anti-D will be given 1 vial
at 28 weeks proactively (do not know baby's type)
-postpartum administration: Rh negative female that does not
make anti-D who gave birth to a Rh positive baby (even weak
D positive) will be given a number of vials of Rhogam that is
calculated based on how much D antigen she is exposed to
positive DAT due to rhogam - ANSWER✔✔if a mother was
administered rhogam at 28 weeks it can still be in her system
at birth
-a positive DAT showing anti-D coatinginfant 's cells can occur
due to rhogam that is still in the system
inelligible for rhogam - ANSWER✔✔-Rh neg mother and Rh neg
baby: no rhogam needed after birth, no risk of D exposure
-Rh neg mother that is already producing anti-D: preventative
measures will not work at this point
-Rh positive mother: no risk of forming anti-D
Complete Questions and Detailed Answers
| (Graded A+)
ABO antibodies - ANSWER✔✔ IgM antibodies that *have an IgG
component* and can cause HDFN
middle cerebral artery peak systolic volume (MCA-PSV) -
ANSWER✔✔using a doppler ultrasound to find the velocity of
blood flow through the cerebral artery of the fetus
-compare to a mean value for their gestational age
-having a velocity of 1.5x or higher the mean (MoM) indicates
anemia
homozygous - ANSWER✔✔cells that are used to screen a
maternal antibody titer have ____________________ expression of
antigens
-these cells have the strongest expression of antigen, so will
have the best chance to react with the maternal antibodies
maternal antibody elution titer - ANSWER✔✔if clinically
significant IgG antibody is present in mother, perform serial
dilutions of her serum and test it against homozygous cells
corresponding to the antigen multiple times throughout
pregnancy to monitor progression of antibody
-perform multiple times to see if antibody is increasing
(indicate risk of HDFN)
,-only test AHG phase so that you are only seeing IgG
antibodies
titer (maternal antibody elution titer) - ANSWER✔✔the
reciprocal of the most dilute maternal serum preparation that
is showing visible agglutination (1+)
-e.g. if the tube is 1:4, read it as 4
-*do not count w+*
-a titer of 16 is clinically significant
-for anti-K a titer of 8 is clinically significant
-a 2 fold increase in titer (goes up by 2 tubes) since the last
test is clinically significant
titer score (maternal antibody elution titer score) -
ANSWER✔✔every tube of maternal serum dilution that is
reactive is assigned a point value, and added together
- 4+= 12 points
- 3+= 10 points
- 2+= 8 points
- 1+= 5 points
- w+= 2 points (*weak positives are counted*)
-an increase in score of 10 since the last test is clinically
significant
-higher titer score indicates a stronger reacting antibody
(higher avidity)
, Rh immunoglobulin (RhIg/ RhoGAM) - ANSWER✔✔a
concentrate of IgG anti-D that is derived from pooled human
plasma
-is administered to protect non-immunized Rh negative
females from forming anti-D during pregnancy
-rhogam coats fetal D antigen that is found in maternal
circulation and destroys it before the mother's immune
system can form antibodies
rhogam candidate - ANSWER✔✔-prenatal administration: Rh
negative female that does not make anti-D will be given 1 vial
at 28 weeks proactively (do not know baby's type)
-postpartum administration: Rh negative female that does not
make anti-D who gave birth to a Rh positive baby (even weak
D positive) will be given a number of vials of Rhogam that is
calculated based on how much D antigen she is exposed to
positive DAT due to rhogam - ANSWER✔✔if a mother was
administered rhogam at 28 weeks it can still be in her system
at birth
-a positive DAT showing anti-D coatinginfant 's cells can occur
due to rhogam that is still in the system
inelligible for rhogam - ANSWER✔✔-Rh neg mother and Rh neg
baby: no rhogam needed after birth, no risk of D exposure
-Rh neg mother that is already producing anti-D: preventative
measures will not work at this point
-Rh positive mother: no risk of forming anti-D
