Question

1. Adrian is a 29-year-old female visiting her physician. She is 10 weeks into her first pregnancy. What should be ordered as part of her prenatal workup? Urine test: for proteins and glucose levels Prenatal testing: cell- free fetal DNA screens for down syndrome, trisomy 13, trisomy 19, and Rh fetal blood type. Another type of testing that can be done is NIPT screen for Down syndrome and other chromosomal abnormalities.

2. Initial testing indicates that Adrian is B negative. Her antibody screen is negative. Should any additional tests be performed? If yes, what and when should they be performed?

3. Adrian was seen by her OB at 28 weeks. Her antibody screen is repeated and is still negative. She received a 300-ug dose of RhIG. At 39 weeks, Adrian delivers a 7 pound, 1 ounce baby girl. What testing, if any, should be performed at the time of delivery? Cord blood results indicate that Adrian’s baby girl is O negative.

4. Would Adrian be a candidate for RhIG postpartum?

5. What additional tests need to be performed on Adrian before RhIG is given?

Part 2: (12 points) 1. Dana is 16 weeks pregnant and is seen by her OB. She had one miscarriage (no RhIG given) and one full-term pregnancy, in which she received RhIG. The child of the full-term pregnancy needed phototherapy for jaundice. She is O negative and her prenatal screen indicates a positive antibody screen. What additional tests should be performed? Anti-D is identified as the culprit. Antibody titers were performed at 16 weeks and at 20 weeks. Her 16 week titer is 1:8 and her 20 week titer is 1:64.

2. Why perform antibody titration?

3. Are the titration results significant?

4. Why is titration recommended?

5. Amniocentesis is performed at 25 weeks and shows a ΔOD of 0.10. Using the Liley graph, what might be expected in this case given the patient results and her history? Dana delivers a 5 pound, 5 ounce baby girl at 37 weeks. The cord blood results indicates the following: The baby’s hemoglobin is 13.5 g/dL with a bilirubin of 5.9 mg/dL.

Anti-A	Anti-B	Anti-D	Weak D	D control	DAT
0	3+	0	2+	2+	2+

1. What is the ABO and D type interpretation? B positive

2. What additional testing is necessary?

3. Does the baby have HDFN? If so, what is the cause? Use laboratory data to support your conclusions. The next night, Dana’s baby has a bilirubin of 18.1 mg/dL. An exchange transfusion is ordered by the attending physician. 4. What ABO/D type should be used? 5. How should it be tested? 6. What are the special requirements for blood used for an exchange transfusion?

Part 3: (10 points) For each of the following examples, indicate if HDFN is possible and explain your answer.

1: Group A pos Baby born to Group O pos Mom

2: Group O pos Baby born to Group B pos Mom

3. Group A pos Baby born to Group B neg Mom

4. Group O pos Baby born to Group O pos Mom with anti-K antibody

5. Group O neg Baby born to Group O pos Mom with anti-Lua antibody

Answer 1

2.An RBC antibody screen is performed early in pregnancy as part of every womans pregnancy work up. In Th- negative women it is also done at 28 weeks, prior to giving an injection of the immuneglobulin and after delivery if the baby is determined to be Rh- positive. In negative pregnant women with known antibodies ,the RBC antibody screen is sometimes ordered as a monitoring tool to roughly track the amount of antibody present.

3.The bloodtest which is repeated between 24 and 28 weeks of pregnancy and the test still shows that the woman is not senditized ,she will need another antibody test until delivery. The baby will have a blood test at birth. If the newborn has Rh- positive blood, the women will have an antibody test to see if she were sensitized during late pregnancy or childbirth.

4.Rh incompatability devrlops only when the mother is Rh negative and the infant is Rh positive. First born infants are often not affected unless the mother had past miscarriages. If the mother is Rh negative, the women should receive RhoGAM during every pregnancy unless doctor has determined that the woman have already been sensitized or if the fetus is confirmed to be Rh negative. So in this case it is not needed.

5.In the initial visit Blood type and antibody screen.

If positive, repeat antibody screen monthly until delivery. Test ccord blood for ABO ,Rh, Direct Antiglobulin Test, haemoglobin and bilirubin at delivery.

Rh(D) negative

Repeat antibody screen at 26-28 weeks  

If negative antibody screen, repeat antibody screen and Kleihauer at delivery.