Rhesus D Prophylaxis, The Use of Anti-D Immunoglobulin

Question 1

Prior to the availability of anti-D immunoglobulin (anti-D Ig), incidence of Rh D alloimmunisation in D negative women following two deliveries of D positive, ABO-compatible, infants was approximately

Answer 1

16 %

Question 2

Following routine post-partum administration of anti-D Ig, the rate of alloimmunisation dropped to approximately .

Answer 2

2 %

Question 3

how much further reduction in sensitisation rate was achieved by introducing routine antenatal prophylaxis during the third trimester of pregnancy

Answer 3

0·17 to 0·28%

Question 4

Associated with reduction in sensitisation is a reduction

in mortality associated with HDN,

Answer 4

from 46/100 000 births to 1·6/100 000 births

Question 5

• Following potentially sensitising events, anti-D Ig should be administered till how long?
• If, exceptionally, this deadline has not been met after the sensitising event

Answer 5

• as soon as possible and always within 72 h of the event.

- some protection may be offered if anti-D Ig is given up to 10 days

Question 6

• In pregnancies<12 weeks gestation, anti-D Ig prophylaxis is indicated in what conditions?
• How much minimum dose and test of FMH?

Answer 6

only indicated following

• ectopic pregnancy,
• molar pregnancy,
• therapeutic termination of pregnancy and
• in uterine bleeding where this is repeated, heavy or associated with abdominal pain.
• 250 IU.
• test for FMH is not required

Question 7

• For potentially sensitising events between 12 and 20 weeks gestation, How much minimum dose and test of FMH?

Answer 7

• minimum dose of 250 IU within 72 h of event.

- test for FMH is not required.

Question 8

• For potentially sensitising events after 19+6 weeks in D negative, previously non-sensitised
• How much minimum dose and test of FMH?

Answer 8

• minimum anti-D Ig dose of (500 IU = 100 mcg) within 72 h

- test for FMH is required.additional dose(s) of anti-D Ig administered as necessary

Question 9

• All D negative pregnant women who have not been

previously sensitised should be offered routine antenatal prophylaxis with anti-D Ig (RAADP)

Answer 9

• either with a single dose (1500 IU = 300 mcg )regimen at around 28 weeks, or
• two-dose regimen (500 IU = 100 mcg) given at 28 and 34 weeks

Question 10

• When to take 28-week sample (second screen in pregnancy) for blood group and antibody screen?.

Answer 10

• prior to the first routine prophylactic anti-D Ig injection being given.

Question 11

Do we give RAADP if anti-D Ig already given for a potentially sensitising event?

Answer 11

• Routine Antenatal Anti-D Ig Prophylaxis (RAADP)
  should be regarded as a separate entity and
• administered regardless of, and in addition to, any anti-D Ig given for potentially sensitising event

Question 12

• Following birth, ABO and Rh D typing should be

performed on cord blood and if the baby is confirmed to be D positive, further steps

Answer 12

All D negative, previously non-sensitised women offered

• at least 500 IU of anti-D Ig within 72 h
• Maternal samples be tested for FMH and additional dose(s) given as guided by FMH tests.

Question 13

• In the event of an intrauterine death (IUD), where no

sample can be obtained from the baby, further steps?

Answer 13

• appropriate dose of prophylactic anti-D Ig should be administered to D negative, previously non-sensitised women within 72 h of the diagnosis of IUD, irrespective of the time of subsequent delivery

Question 14

• Where intra-operative cell salvage (ICS) is used during CS in D negative, previously nonsensitised women, and where cord blood group is confirmed as D positive (or unknown),

Answer 14

• minimum dose of 1500 IU anti-D Ig following re-infusion of salvaged red cells, and
• maternal sample taken for estimation of FMH 30–45 min after reinfusion in case more anti-D Ig is indicated.
• inform transfusion laboratory if ICS used to ensure that correct dose of anti-D Ig is issued

Question 15

Potentially sensitising events in pregnancy

Answer 15

1 - Amniocentesis, chorionic villus biopsy and cordocentesis
2 - Antepartum haemorrhage/Uterine (PV) bleeding in pregnancy
3 - External cephalic version
4 - Abdominal trauma (sharp/blunt, open/closed)
5 - Ectopic pregnancy
6 - Evacuation of molar pregnancyI
7 - ntrauterine death and stillbirth
8 - In-utero therapeutic interventions (transfusion, surgery, insertion ofshunts, laser)
9 - Miscarriage, threatened miscarriage
10 - Therapeutic termination of pregnancy
11 - Delivery – normal, instrumental or Caesarean section
12 - Intra-operative cell salvage