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QuestionChoice
An indirect Coombs test can be used to determine whether there are antibodies to the Rhesus factor in the mother's blood and therefore whether she has been "sensitised". A positive Coombs test indicates whether a Rh-positive foetus has the possibility of being harmed from rhesus D alloimmunisation. In this case, a sensitisation event has occurred in a miscarriage >12 weeks, and so anti-D must be given regardless
33107
e
Perform indirect Coombs test before administration of anti-D
QuestionChoice
Anti-D is given regardless of the biological father's rhesus status
33105
c
Anti-D only required if the biological father is rhesus positive
QuestionChoice
A Kleihauer test measures the amount of foetal haemoglobin transferred from a foetus to a mother's bloodstream following exposure to a sensitising event from a RhD positive baby. It is conducted on all RhD negative women who have delivered a RhD positive baby, in pregnant women who have had a potentially sensitising event at >20 weeks gestation, and on all pregnant women who have had an invasive procedure. The test helps with dosing Anti-D immunoglobulin. In this case, however, a sensitisation event has occurred in a miscarriage >12 weeks, and so anti-D must be given regardless
33106
d
Perform a Kleihauer test before administration of anti-D
QuestionChoice
In pregnancies between 12 and 20 weeks gestation, anti-D immunoglobulin should be given in any sensitising event such as miscarriage, even if managed medically. No tests are required prior to administration
33103
a
Give anti-D immunoglobulin within 72hrs
QuestionChoice
Miscarriage in pregnancies >12 weeks require anti-D given to prevent rhesus D alloimmunisation and haemolytic disease of the newborn. It is also required in a number of conditions, including termination of pregnancy, ectopic pregnancy, or abdominal trauma
33104
b
No need for anti-D immunoglobulin
Concept
Chapter
# Overview

The D antigen is found on red blood cells and is an important antigen in the rhesus factor system.

Rhesus isoimmunisation can occur when a rhesus negative mother has a baby which is rhesus positive. If any foetal red blood cells enter the maternal circulation, the mother will form anti-D antibodies against them.

The maternal anti-D antibodies can cross the placenta in subsequent pregnancies and cause Rhesus haemolytic disease if the future baby is rhesus positive.

# Sensitisation events

“Sensitisation” events are events which cause foetal blood to cross the placenta into the maternal circulation and thus these are indications for anti-D prophylaxis.

Examples of sensitisation events include:

- Antepartum haemorrhage
- Placental abruption
- Abdominal trauma
- External cephalic version
- Invasive uterine procedures such as amniocentesis and chorionic villus sampling
- Rhesus positive blood transfusion to a rhesus negative woman
- Intrauterine death, miscarriage or termination
- Ectopic pregnancy
- Delivery (normal, instrumental or caesarean section)

# Testing

All mothers should be tested for rhesus status and anti-D antibodies at booking

# Management of the Rh-D negative mother

Presence of anti-D antibodies can result in incompatibility and haemolysis in future pregnancies. To attenuate this risk, anti-D antibodies are given to patients who have experienced a sensitising event. Anti-D is also given to all non-sensitised Rhesus negative mothers at 28 weeks. Note that anti-D has no effect once sensitisation has already occurred (it is prophylactic only).
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Rhesus isoimmunisation
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Obstetrics
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Rhesus isoimmunisation
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Ectopic pregnancy 1
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Rhesus isoimmunisation
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Haemolytic disease of the newborn
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Rhesus isoimmunisation
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Quesmed Tutorial: Haemolytic Anaemia
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Administer anti-D immunoglobulin within 72 hours after a miscarriage in Rh-negative women to prevent sensitisation.
A 23-year-old woman with antiphospholipid syndrome is 14 weeks pregnant and develops lower abdominal pain and subsequent vaginal bleeding. A transvaginal ultrasound scan confirms an inevitable miscarriage. She is known to be rhesus negative.

Which of the following is the best next step in the management of this patient with regards to anti-D?
a