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Haematology · UK

Rh factor testing - the answer that follows you for life.

ABO and Rh D grouping, extended Rh phenotype, antibody screening and non-invasive fetal RHD genotyping - at a UKAS-accredited UK transfusion lab, with anti-D prophylaxis planned before you need it.

See indicative pricing
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Indicative pricing

What private Rh factor testing costs in the UK.

Indicative ranges across our partner laboratories.

In short

£85–£160, results in 24–48 hours.

Test Indicative range
ABO and Rh D group £45–£90
Group, save and antibody screen £85–£160
Extended Rh phenotype (C, c, E, e) £120–£220
Weak D / partial D molecular typing £180–£320
Fetal RHD genotyping (cffDNA, from 11 weeks) £220–£380
Antenatal anti-D immunoglobulin (single dose) £120–£260
Consultant obstetrics or haematology review £220–£380

Prices vary by laboratory and by how much of the panel is needed. Anti-D prophylaxis, cffDNA fetal RHD genotyping and consultant review are separate line items.

The problem

A test that is simple to run and easy to under-plan.

The blood group itself is quick. The bits that go wrong are the antibody screen, the weak D interpretation, and - in pregnancy - the anti-D and cffDNA plan.

  • Do the screen, not just the group

    ABO and Rh D alone will not catch anti-c, anti-K or other clinically significant antibodies. The antibody screen is what makes the panel safe for pregnancy and transfusion.

  • Sort out weak D once, properly

    Historic borderline results are still causing unnecessary anti-D and mismatched transfusion. Molecular typing resolves them in one visit.

  • Plan anti-D on the same day

    Routine antenatal anti-D at 28 weeks and post-event doses within 72 hours - decided at booking, not chased in a labour ward.

When it helps

When Rh factor testing is the right step.

The situations we see most, plus the one red flag that means fetal medicine urgently rather than a routine antenatal appointment.

  • First pregnancy - booking bloods

    The routine booking panel at 8–12 weeks. Rh D status decides whether you need antenatal anti-D and cffDNA fetal typing later.

  • Rh D negative in a new pregnancy

    A second or later pregnancy where a previous baby was Rh D positive - a repeat antibody screen is important before 28 weeks.

  • Any sensitising event in pregnancy

    Bleeding, abdominal trauma, external cephalic version, amniocentesis or CVS - a Kleihauer test and top-up anti-D within 72 hours.

  • Preparing for surgery or elective transfusion

    Group and save before major surgery. Full crossmatch if transfusion is expected.

  • Historical mixed or unclear result

    A weak D or partial D result on old records - molecular typing settles it, so future transfusion and pregnancy planning are safe.

  • Blood donation eligibility check

    Confirming ABO/Rh before signing up as a regular donor or a directed donor for a family member.

  • IVF and egg or embryo recipients

    Recipient blood group check before treatment cycles, particularly relevant for donor egg pregnancies.

  • Red flag: known red-cell antibody

    Anti-D, anti-c, anti-K or another clinically significant antibody in pregnancy needs fetal medicine referral - not a routine antenatal clinic.

Test options

The right panel depends on why you need it.

Each option, explained - from the core ABO/Rh D group through extended phenotype and fetal RHD genotyping.

  • ABO and Rh D typing

    The core test. Forward group on the cells, reverse group on the plasma. Rh D by monoclonal anti-D reagent. The result that shows on your NHS record.

  • Antibody screen (indirect antiglobulin test)

    Detects red-cell antibodies in the plasma that could cause a transfusion reaction or haemolytic disease of the newborn. Positive screens go on to identification.

  • Extended Rh phenotype

    C, c, E and e antigens in addition to D. Useful for patients likely to need regular transfusion - sickle cell disease, thalassaemia, myelodysplasia - to reduce alloimmunisation.

  • Weak D and partial D molecular typing

    For borderline serological D results. Weak D types 1, 2, 3 can safely receive Rh D positive blood; partial D and other weak D types are treated as Rh D negative.

  • Kell, Duffy, Kidd and MNS typing

    Broader red-cell antigen typing before long-term transfusion, or in a mother whose partner carries a clinically significant antigen.

  • Fetal RHD genotyping (cffDNA)

    Non-invasive fetal blood grouping from maternal plasma from 11 weeks. Avoids unnecessary anti-D in the roughly 40% of Rh D negative women carrying an Rh D negative baby.

  • Kleihauer–Betke or flow FMH

    Quantifies feto-maternal haemorrhage after a sensitising event so the correct anti-D dose is given. Not a grouping test itself, but ordered alongside.

  • Direct antiglobulin test (DAT / Coombs)

    On cord or neonatal blood to detect maternal antibodies coating baby’s red cells - the paediatric side of the same conversation.

Safety and interpretation

What to expect afterwards - honestly.

Rh factor testing itself is low risk. The things worth planning are the antibody screen interpretation, the weak D question, and - in pregnancy - the anti-D and fetal RHD plan.

  • A blood test - genuinely low risk

    A small bruise, occasional light-headedness. Serious reactions are vanishingly rare. Phlebotomists are trained to spot and manage the odd faint.

  • Rh D negative is common, not a problem in itself

    About 15% of the UK population is Rh D negative. It only becomes clinically important during pregnancy or transfusion - which is why we plan ahead, not react late.

  • Anti-D prophylaxis is safe and well-established

    Routine antenatal anti-D at 28 weeks - plus post-event doses within 72 hours of any sensitising event - has cut haemolytic disease of the newborn dramatically since the 1970s.

  • cffDNA lets us skip anti-D when it is not needed

    If fetal RHD genotyping shows an Rh D negative baby, no anti-D is needed. This is now NICE-endorsed practice and reduces unnecessary blood product exposure.

  • A positive antibody screen is not a crisis

    Many antibodies are cold-reacting and clinically irrelevant. Identification tells us whether monitoring, fetal medicine referral or a change in transfusion plan is needed.

  • Weak D is not the same as Rh D negative

    Historic borderline results deserve molecular typing - otherwise you may be given the wrong blood at a future transfusion or receive unnecessary anti-D in pregnancy.

  • Anti-D is a pooled human blood product

    It is screened and virally inactivated. Some patients decline for religious reasons - we discuss the alternatives openly rather than pressure a decision.

  • Results follow you for life

    Your ABO and Rh group do not change. Keep the report - it saves time in an emergency and in future pregnancies.

  • Red flags after a sensitising event

    Vaginal bleeding, abdominal pain after trauma or reduced fetal movements need same-day obstetric assessment as well as anti-D, not a routine follow-up.

Reading your report

Your blood group report in four parts. Read the last one first.

Whichever laboratory ran it, the report the haematologist sends you keeps to the same shape.

A UK consultant haematologist reviewing a patient’s blood group report

A quiet reminder

Transfusion language is precise and can read coldly - we translate it for you.

If you would like us to talk you through the report before your GP or midwife appointment, just ask.

  1. 01 Header

    ABO group and Rh D status

    The single line most people look for - A, B, AB or O, and whether you are Rh D positive or negative.

  2. 02 Technique

    Method and reagents

    Column agglutination or tube technique, monoclonal anti-D reagent used, and whether molecular typing was needed for a borderline result.

  3. 03 Findings

    Antibody screen and phenotype

    Whether any clinically significant red-cell antibodies were found, and - if requested - your extended Rh, Kell, Duffy or Kidd phenotype.

  4. 04 Impression

    Transfusion and anti-D plan

    Read this first: what blood you can safely receive, and - in pregnancy - whether antenatal anti-D and fetal RHD genotyping are recommended.

Recognised by major UK insurers

BupaAXA HealthVitalityAvivaWPACignaHealixBupaAXA HealthVitalityAvivaWPACignaHealixBupaAXA HealthVitalityAvivaWPACignaHealix

Rh factor and antibody screening are usually covered as part of antenatal care or pre-surgical work-up. Elective donor and self-pay tests are typically out of pocket.

Frequently asked

Everything we get asked about Rh factor.

Quick answers on pregnancy, anti-D, cffDNA, weak D and cost.

  • What does it mean to be Rh D positive or Rh D negative?

    The Rh D antigen is a protein on the surface of red blood cells. If you carry it, you are Rh D positive; if you do not, you are Rh D negative. About 85% of the UK population is Rh D positive. On its own it changes nothing about your health - it matters only when Rh D negative and Rh D positive blood meet, in pregnancy or transfusion.

  • Why does Rh factor matter in pregnancy?

    If an Rh D negative mother carries an Rh D positive baby and fetal cells cross into her circulation, she can form anti-D antibodies. Those antibodies can attack a future Rh D positive baby’s red cells, causing haemolytic disease of the newborn. Routine antenatal anti-D immunoglobulin and post-event doses prevent this from happening in the vast majority of pregnancies.

  • Do I still need anti-D if my partner is also Rh D negative?

    Almost never. Two Rh D negative parents produce an Rh D negative baby, and no anti-D is needed. UK practice is increasingly to use non-invasive fetal RHD genotyping from maternal blood from around 11 weeks to confirm the baby’s status and avoid unnecessary anti-D.

  • How accurate is fetal RHD genotyping?

    Modern cell-free fetal DNA testing for RHD is over 99% accurate from around 11 weeks. It is endorsed by NICE for routine use in Rh D negative pregnant women to target antenatal anti-D only to those who need it.

  • What is a weak D result?

    Weak D means the red cells carry fewer Rh D antigens than usual, giving a borderline serology result. Molecular typing sorts it into weak D types (usually treated as Rh D positive) or partial D and other variants (treated as Rh D negative to be safe). It matters most for transfusion planning and pregnancy management.

  • How much does a private Rh factor test cost in the UK?

    Roughly £45–£90 for ABO and Rh D alone, £85–£160 with an antibody screen, £120–£220 for extended Rh phenotyping, and £220–£380 for cell-free fetal RHD genotyping. A single dose of antenatal anti-D is £120–£260 depending on brand and dose.

  • Can my Rh factor change?

    No. ABO and Rh groups are set by your genes and do not change over your lifetime. The only situations where reports look different are: a laboratory error on an old test, a borderline weak D not previously characterised, or after a large stem cell or bone marrow transplant from a donor of a different group.

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