What d moes it mean to be Rhesus negative?
RhD - means that the red blood cells do not carry RhD antigen
If RhD- woman is carrying RhD+ foetus and any foetal blood cross into maternal circulation (sensitizing event) → maternal reaction to the 'foreign D' antigens on RBCs of the foetus → antibodies anti D are produced → problem not in a current pregnancy but in a later ones (antibodies from mum may cross the placenta and destroy foetal RBCs)
This leads to haemolytic disease of newborn and either severe disability or stillbirth
When to do routine anti-D prophylaxis for women that are RhD-?
at 28 weeks, 34 weeks and if after a baby is born and its blood is tested as RhD + then we also give postnatal anti-D prophylaxis
How does anti-D prophylaxis work?
- Anti-D prophylaxis prevents RhD- women from producing anti-D antibodies against RhD+ foetus
- This is achieved because anti-D immunoglobulins are already provided (so immune system of the mum does not need to produce a new ones)
What's a sensitizing event?
An event when a foetal blood could pass into maternal circulation
What are the doses of anti-D prophylaxis:
- before 20 weeks gestation
- after 20 weeks gestation
- before 20 weeks: 250 iu
- after 20 weeks: 500 iu
Timing and route of anti-D prophylaxis after a sensitizing event has occurred
- give ASAP after a sensitising event (ideally within 72 hours)* still some protection if given within 10 days
- IM injection
Do we give prophylactic anti-D to RhD- women following abortion?
Yes. This is regardless of abortion being medical or surgical → we give anti-D for both
Do we give anti-D prophylaxis to non-sensitised RhD- women in case of ectopic pregnancy?
Do we give anti-D prophylaxis to non-sensitised RhD- women in case of spontaneous miscarriage?
Yes. To all types of miscarriage after 12 weeks pregnancy
(given even for threatened miscarriage)
* if miscarriage occurred before 12 weeks of gestation → then anti D not required; unless uterine evacuation was performed
In what cases, we should give anti-D prophylaxis to RhD- women?
- ectopic pregnancy
- miscarriage (after 12 weeks)
- termination of pregnancy
- antepartum haemorrhage
- closed abdominal injury
- external cephalic version of foetus
- invasive prenatal diagnosis (amniocentesis, foetal blood sampling)
- other intrauterine procedures (
- intrauterine death
How much of anti D prophylaxis do we give to RhD- woman after she gave birth to RhD + child?
500 iu of anti - D within 72 hours
If mum is RhD- and dad is RhD- do we need to give anti-D prophylaxis?