# Rhesus isoimmunisation - Category: chronic - Review status: reviewed (every claim checked against a document named on this page) - Sources: ICPC-3 (WONCA International Classification of Primary Care, 3rd edition) class WD71.06 - condition scope only, no dose · No dose - referral pathway, no medicine given in primary care · Rho(D) Immune Globulin - StatPearls - NCBI Bookshelf - https://www.ncbi.nlm.nih.gov/books/NBK557884/ · Pregnant Women with Red Cell Antibodies - Scottish National Clinical Guidance, 3rd edition, February 2020 (SNBTS Transfusion Team; drawing on the BSH and RCOG guidelines), sections 2.1-3.1 - https://www.nn.nhs.scot/hats/wp-content/uploads/sites/12/2020/06/Scottish-Red-Cell-Antibodies-in-Pregnant-Women-Guidance-Feb-2020-FINAL.pdf - Verified date: 2026-08 ## Verified against - No dose - referral pathway, no medicine given in primary care - Rhesus isoimmunisation - disease-level clinical article (rhesus-isoimmunisation-clinical.txt) - Pregnant Women with Red Cell Antibodies - Scottish National Clinical Guidance, 3rd edition, February 2020 (SNBTS Transfusion Team; drawing on the BSH and RCOG guidelines), sections 2.1-3.1 - Rho(D) Immune Globulin - StatPearls - NCBI Bookshelf - https://www.ncbi.nlm.nih.gov/books/NBK557884/ ## Treatment metadata - No drug therapy in primary care (Referral & Advice) ## Complete treatment card ```text RHESUS ISOIMMUNISATION Sources: ICPC-3 (WONCA International Classification of Primary Care, 3rd edition) class WD71.06 - condition scope only, no dose · No dose - referral pathway, no medicine given in primary care · Rho(D) Immune Globulin - StatPearls - NCBI Bookshelf - https://www.ncbi.nlm.nih.gov/books/NBK557884/ · Pregnant Women with Red Cell Antibodies - Scottish National Clinical Guidance, 3rd edition, February 2020 (SNBTS Transfusion Team; drawing on the BSH and RCOG guidelines), sections 2.1-3.1 - https://www.nn.nhs.scot/hats/wp-content/uploads/sites/12/2020/06/Scottish-Red-Cell- Antibodies-in-Pregnant-Women-Guidance-Feb-2020-FINAL.pdf Review status: REVIEWED against No dose - referral pathway, no medicine given in primary care, Rhesus isoimmunisation - disease-level clinical article (rhesus- isoimmunisation-clinical.txt), Pregnant Women with Red Cell Antibodies - Scottish National Clinical Guidance, 3rd edition, February 2020 (SNBTS Transfusion Team; drawing on the BSH and RCOG guidelines), sections 2.1-3.1, Rho(D) Immune Globulin - StatPearls - NCBI Bookshelf - https://www.ncbi.nlm.nih.gov/books/NBK557884/ (2026-08) IS IT THIS? - reference only, to read alongside your own examination RED FLAGS (4) - Anti-D is given prophylactically at 26 to 28 weeks, and again within 72 hours of delivering an Rh-positive infant - For any known or suspected exposure to Rh-positive red cells, anti-D must be given within 72 hours, dosed to the volume of exposure - In pregnancy, anti-D is repeated every 12 weeks from the first injection to keep enough passive antibody present - Anti-D must not be given to an Rh-positive patient - a haemolytic reaction may follow SIGNS - what you find (2) - In the affected newborn: jaundice, anaemia, kernicterus and hydrops fetalis from maternal antibody attacking fetal red cells [anaemia · hydrops fetalis · jaundice · kernicterus] - Intrauterine death can occur without intrauterine transfusion, and a surviving infant may have developmental delay, hearing loss and hypotonia [developmental delay · hearing loss] TESTS (4) - The direct antiglobulin (Coombs) test shows red cells already coated with antibody or complement, and is the test for haemolytic disease of the fetus and newborn - The indirect antiglobulin test detects antibody binding in vitro - it is the antibody screen, crossmatch, titration and phenotyping test - A negative antiglobulin test does not exclude antibody on the red cells; small amounts of bound IgG or C3 can read negative - The five clinically significant Rh antigens are D, C, c, E and e; Rh negative means lacking the D antigen IF NOT THIS - what else fits (4) - The first D-positive pregnancy is unlikely to be affected, because mixing usually happens at delivery and the first antibodies are IgM, which does not cross the placenta - It is typically the second Rh-positive fetus that is affected, once isotype switching has produced placenta-crossing IgG - Before immunoprophylaxis, 1% of all pregnancies ended in fetal death from this; it now affects 3 to 8 per 100,000 pregnancies - Fetomaternal mixing most often happens at labour and delivery, but can in theory happen at any point in the pregnancy Source StatPearls "Rh Blood Group System" (NBK594252) for the disease, and StatPearls "Rho(D) Immune Globulin" (NBK557884) for anti-D timing; neither chapter is titled for this condition, and this card is scoped to their haemolytic-disease sections Status traced to the source above 1. NO DRUG THERAPY IN PRIMARY CARE (REFERRAL & ADVICE) [1st line] Adult Rhesus-negative sensitisation detected on antenatal screening; the GP recognises the result and refers for specialist monitoring, with anti-D prophylaxis given by obstetric services. - Refer, with advice Peds Children follow the same pathway: recognise and refer. No primary-care medicine is implied. Source No dose - referral pathway, no medicine given in primary care Why Rhesus-negative sensitisation detected on antenatal screening; the GP recognises the result and refers for specialist monitoring, with anti-D prophylaxis given by obstetric services. Caution A rising antibody level or an ultrasound sign of fetal anaemia is the trigger for a fetal medicine referral. Scottish national guidance asks for referral for fetal assessment once the antibody level reaches the moderate or high risk range (its Table 1, Section 1.3), and for referral to the fetal medicine unit in Glasgow at any stage where ultrasound suggests anaemia - ascites, pleural effusion, hydrops, placentomegaly. Its list of triggers for discussing a woman with that unit also includes an MCA Doppler PSV above 1.5x MoM and ultrasound evidence of fetal anaemia. A rise still matters when the baby has tested antigen negative: where later testing shows the antibody level climbing, the guidance asks that the fetus be considered possibly antigen positive after all. No medicine is prescribed for this in primary care - this entry is for recognition and referral. Anything given is decided by the service it is referred to. RED FLAG - Severe fetal and neonatal complications of Rh isoimmunisation (hemolysis leading to jaundice, anemia, kernicterus, hydrops fetalis, and potential intrauterine death) are not detailed on the page NO ANTI-D DOSE IS PRINTED, AND THAT IS THE SOURCE'S POSITION, NOT AN OMISSION. The cited Rho(D) immune globulin article states that indications vary by manufacturer, that any exposure is dosed according to the amount of red-cell exposure per the manufacturer's guidance, and that dosages are expressed in micrograms or international units on a scale of 1 microgram to 5 international units. It gives no figure of its own, so none is invented here. THE TIMING IS THE PART A GP CAN GET WRONG, AND IT IS STATED. The same article gives a single prophylactic dose at 26 to 28 weeks of pregnancy, another within 72 hours of delivering an Rh-positive baby, and repeat dosing every 12 weeks from the first injection to keep enough passive antibody present. Any known or suspected exposure to Rh-positive red cells is also covered within 72 hours. WHAT THE 72 HOURS BUYS, in the article's own figures: given within 72 hours of a full- term delivery, sensitisation falls from 12 to 13% down to 1 to 2%; on the 28-week plus postpartum schedule it falls below 1%. If it was missed after delivery, the article says to give it as soon as possible inside those 72 hours. TWO PRACTICAL CONSEQUENCES the article names: the patient is watched for at least 20 minutes afterwards for a systemic reaction, and a live vaccine is deferred until at least 12 weeks after the last dose. Prices are indicative (dataset snapshot 2026-06); verify with the pharmacy. ``` --- Dawaa Reference is a reference for prescribers, not a medical device, and does not replace clinical judgement. [Privacy policy](/privacy)