sukruthi rh neg.pptx obstetrics and gynaecology

Obstetrics and gynaecology

1. RH ISOIMMUNIZATION DR. SUKRUTHI

2. Background Rhesus Antigen first identified by karl Landteiner and Alexander solomon wiener in 1940 Later by philip levine 1941 demonstrated (HDFN) ertthroblastsis fetalis due to Rh isoimmunization Bevis first recognized that spectrophotometric measurements of amniotic fluid appeared to change at optical density 450 nm in fetuses who were shown to have HDFN In 1956, Liley performed the first amniocentesis in a human to assess the fetal bilirubin through a spectrophotometric analysis in a pregnancy at risk for anemia observed change in the optical density at 450 nm (delta OD450) to predict the severity of HDFN in fetuses

3. RHESUS FACTOR

4. Rh system complex blood grouping system Gene present on short arm chrosome 1 p Includes 50 antigens 6/50 most imp Main antigens are D Cc Ee , inherited one from eah parent as 2 sets of 3 alleles Absence of D antigen determines Rh negative status HDFN also be caused non-rhesus blood group system- (Kell, Kidd, Duffy, etc.)

5. Incomplete expression result in a weekly positive patient-Du variant of weakly Rh positive patient they may even be determined as rh negative A mother with Du Rh blood group may become sensitized from a positive fetus or the other way around may take place, needs Anti- D Most immunogenic is D Immunogeicity D>c>E>e>C>G F e t a l R B C s t a r t s f o r m i ng f r o m D a y - 2 1 s t p o s t fertilization M a n i f e s t a t i o n o f R h a n t i g e n o n f e t a l R B C - D a y 3 8 p o s t f e r t ilization .

6. Approach to Non immunized Woman All Rh-negative women should ideally have an indirect coomb’s test (ICT) for screening of Rh antibodies at 1st antenatal visit. This is preferably done irrespective of the husband’s Rh status to ensure that prior sensitization events are not missed.

7. Rh Isoimmunization /Alloimmunization when mother is Rh negative and father positive , fetus can be Rh positive this induce alloimmunization following FMH leading to hemolytic disease of the fetus and newborn (HDFN). Usually first child will escape as primary response by IgM , macromolecule subsequent pregnancies affected due to IgG which an cross placenta .I t ta ke s al mo st 6 mo nt hs for I gG t o de ve lop by t hi s th is f ir st ch il d wi ll b or n. Ananastic reaction: Exposure to antigen for second time , antibodies will strongly produced and destoy fetal RBC.

8. Risk of Alloimmunisation In Rh -ve mother Rh +ve father( irrespective zygosity) 67.5%Babies become Rh +ve Risk of Rh isoimmunization after first Rh positive pregnancy AB O compatible (80%)- 16% ABO incompatible (20%)- 1.5%-2% Overall risk of isoimmunisation -13.2% AFTER ANTI -D Postpartum only 12-13% to 1-2% Anteparum & Postpartum both 1%to 0.2 .

9. Risk of alloimmunization with non D antigens Risk of alloimmunization with non D antigens ABO incompatabiliy is rarely assosiated with HDFN related morbidity (<0.05%) as A and B antigens are weakly expressed on fetal RBCs Prevalence of non ABO antibodies 1-2% MC non ABO RBC antibodies impliated in HDFN include anti-kell,anti -E& anti-C.

10. Potential sensitizing events Significant bleeding during threatened abortion Spontaneous miscarriage Medical termination opregnancy Surgical termination o pregnancy Ectopic pregnancy Hydatidiform mole** Placenta Previa with bleeding Blood transfusion Chorion villus sampling Embryo reduction Amniocentesis Abruptio placentae Blunt trauma Intrauterine fetal demise External cephalic version Invasive fetal procedures IUD

11. Fetomaternal Hemorhage Transplacental hemorrhage 1st trimester 5-8% 1-5ml 2nd trimester 14-18% 1-25ml 3rd trimester 25-30% 1-350ml Parturition 50% 1-350ml Spontaneous 75-80% Critical sensitizing volume - 0.1ml C r i t ical t i t r e 1 : 1 6

12. Occurs in as many of 75 % of women in delivery. Increases with gestational age ( 30% in third trimester) Majority in <3ml is sufficient to cause alloimmunization in 15-50% of women. Ab response to FMH, varies considerably in individuals and depends on GA Volume of hmrge Immunogenic response capacity of mother 1/3 are nonresponders Strenth of antigenic stimulus

13. Of the cases where the FMH is greater than 4 ml,50% will have occurred during normal delivery. Following clinical circumstances are more likely to be associated with a large FMH: Traumatic deliveries including caesarean section Manual removal of the placenta Stillbirths and fetal deaths Abdominal trauma during the third trimester Twin pregnancies(at delivery) Unexplained hydropsfetalis .

14. FMH measurement By Qualitative - Rossette test Quantitative -KB test, Flow cytometry

15. Kleihauer test is performed from maternal blood within 2 hours of delivery to identify RhD negative women with a large feto -maternal haemorrhage who require additional anti-D immunoglobulin. Quantifiation of FMH Test is based on the fact that an acid solution elutes adult but not fetal haemoglobin from the red cells. MaternaL RBC appear as ghost cells It can detect as little as 0.2 ml of fetal blood diluted in 5 ml of maternal blood. It has a high false positive rate though. kleir betke test

16. Calculate number of fetal cells per 50 lpf 5 cells per 50lpf =0.5ml bleed. Additional anti-D = 10mcg for every 0.5ml RBC /1ml og fetal blood Alternative methods : Flow cytometry : It has the advantage that the results are more accurate and is helpful in women with high levels of fetal haemoglobin , as it detects RHD positive cells. Rosetting technique : F or quantifying FMHs of over 4 ml.

17. HOW TO REDUCE FMH? ANTENATAL PERIOD Invasive test only if absolutely indicated Extrauterine /intrauterine manipulation only if absolutely indicated Force avoided during all manipulations Abdominal palpation minimised in placental abruption. VAGINAL DELIVERY Immediate cord clamping no fundal pressure covering episiotomy with gauze

18. INTRAPARTUM Forceps deliveries Caesarean sections Still births Multiple pregnancies Hydrops fetalis Placental abruption Manual removal of placenta POSTPARTUM – B lood transfusion Ergometrine is avoided MROP is avoided During CS: Blood spill into peritoneal cavity minimised /avoided MROP is avoided Uterus to be handled gently

19. ANTI-D Anti-D Ig is a blood product extracted from the plasma of donors who have high circulating levels of anti- D,usually resulting from deliberate immunisation of Rh-negative donors. MOA Accelerated clearance of D positive cells Epitope masking Inhibition due to antibodies against Fc receptor Inhibition of immature dentridic cells Inhibition of B-cell speific to D antigen Take fetal RBC and present to macrophages for hemolysis

20. Introduced in the UK in the 1990s, which led to an even bigger reduction of the incidence of alloimmunization from 18–20/1000 to 0.2%/1000 patients. R C O G offers routine anti-D prophylaxis to all unsensitized Rh negative in the third trimester of pregnancy (28 and 3 2 weeks). RAADP

21. Polyclonal anti -D : prepared from pooled plasma with high titres collected and active against many epitopes Monoclonal anti-D: prepared from ebv d i r e c t e d a g a inst s p e c i fic s i n g l e e p i t o p e . The only source of therapeutic anti-D Ig is human plasma. half life is 24 days

22. If ICT is negative at the first visit, then ICT should be repeated at 28 weeks. Women who are already sensitised , i.e. have immune anti-D, should not be given anti-D prophylaxis. In the non- RhD - sensitised woman, if fetal genotyping indicates that the fetus is RhD negative or if the father is confirmed to be RhD negative then anti-D prophylaxis is not required. However, if a woman has had anti-D immunoglobulin following a sensitizing event or routine antenatal prophylaxis, subsequent ICT is preferably not done. At the time of delivery for all Rh-negative mothers, documentation of the blood group and Rh status of the neonate MUST be done.

23. Recommended doses ( R C O G 2 1 4 ) There are three recommended regimes: Two doses of 500 IU of anti-D immune globulin at 28 and 34 weeks. A single dose of 1500 IU /300mcg at 28 weeks. Two doses of 1000-1650 IU at 28 and 34 weeks. Consent should be obtained and recorded in the case notes. first trimister loss -50-100mcg - anti -D 2nd & 3rd timster loss- 300mcg After molar pregnancy need to be given 300mcg =1500IU

24. If RAADP is declined, this should be documented in the case notes along with the reasons for the decision. In the event that RAADP is declined antibody screening should be performed at booking and at 28 weeks of gestation to identify cases where sensitisation has occurred. Sensitisation occurring in the third trimester is unlikely to cause significant fetal problems in that pregnancy. The disadvantage of this policy is that approximately 40% of RhD-negative women receive unnecessary antenatal anti-D Ig while carrying an RhD-negative child.

25. In 1969, a post-delivery immune-prophylaxis programme with anti-D immunoglobulin was introduced in the UK  significant reduction in frequency of maternal Rh alloimmunization & Associated fetal and neonatal complications The routine dose of anti-D immunoglobulin for postnatal prophylaxis is 300 mcg, which is equivalent to 1500 IU of anti-D and is often enough to suppress 15 ml of Rhesus positive fetal blood cells ( ie 30 ml of fetal blood). Anti-D Ig must be given to every non- sensitised RhD -negative woman within 72 hours following the delivery of an RhD -positive infant for maximum effector if not given can be given upto 1days -28days sensitising of event Post natal prophylaxis

26. After the administration of anti-D immunoglobulin, the antibody screening will detect anti-D antibodies in the patient’s serum, but the titre should not be greater than 1: 4 at term. An anti-D titre greater than 1:4 at term most probably results from alloimmunization rather than from anti-D immunoglobulin administration. Anti-D prophylaxis for unsensitized women who are R hesus-D negative is also recommended after potentially sensitizing events

27. Post partum management Cord blood sample Antobodies by DCT BG Bilirubin level Hb &HCT

28. Special circumstances Tubal ligation- if the woman chooses to have another pregnancy,ligation fails, or she requires future crossmatching of blood products. In cases of recurrent sensitizing events, a repeat dose is required if the event is 3 weeks apart. RhD -positive platelets are transfused, prophylaxis against Rh alloimmunisation should be given . Contraindication to an intramuscular (IM) injection (thrombocytopenia, blood dyscrasias), appropriate IV preparation of the Anti-D immunoglobulin can be used with hematologist consultation.

29. How to give Ideally, Anti-D Ig should be administered into the deltoid muscle ,IM or anterolateral side of thigh IM Women who have a bleeding disorder should receive anti-D Ig via the subcutaneous or intravenous route. Storage cold chain system at < 8degree in refrigirator Given before 4hrs after taking out of fridge

30. Rh negative woman has a 7.2% risk of developing rhesus antibodies within 6 months of giving birth. 99.7% cases covered This policy does not take into account the fact that up to 0.3% of women have a feto -maternal haemorrhage (FMH) greater than 15 ml.

31. cffDNA The advent of cell-free fetal DNA (cffDNA) testing from maternal blood allows noninvasive identification of fetal RBC antigens, including D, c, C, e, E and Kell. The sensitivity and specificity of cffDNA RhD genotyping is almost 100%, so it can be considered a diagnostic test when used in this context.Rhesus D, c, C and e are detectable from 16 weeks of gestation and Kell from 20 weeks. Routine cffDNA-based testing reduces unnecessary anti-D administration and can be cost effective. Determination of paternal RBC antigen status and zygosity may be considered and, very rarely, invasive testing remains necessary for diagnostic certainty (if the father is heterozygous).

32. ICT 2 T echniques Saline agglutination - R esults in titres 1:2,1:4,1:8 N eeds serial dilution manually done ,prone foer mistakes Gel electrophorosis- R esults in grading 4+,3+,2+ simple ,reproducible, doesnt require washing .

33. I C T positive How should pregnancies at risk of fetal anaemia be monitored? The cause of the alloimmunisation, relevant past history and pregnancy outcomes should be ascertained in order to generate an assessment of risk of HDFN. If the fetus carries the corresponding antigen for a maternal antibody which is capable of causing fetal anaemia and if the antibody levels/titres rise beyond the levels then the pregnancy should be monitored weekly by ultrasound, specifically assessing the fetal middle cerebral artery peak systolic velocities (MCA PSV). Referral to a fetal medicine specialist for consideration of invasive treatment should take place if the MCA PSV rises above the 1.5 multiples of the median (MoM) threshold or if there are other signs of fetal anaemia. Fetal monitoring is required (as above) once anti-K is detected.

34. ICT In non immunized women ICT at 1st ANC to be done & at 28 wks if negative give Anti-D Alloimmunised women require blood tests every 4 weeks up to 28 weeks of gestation and fortnightly thereafter. Absolute levels of alloantibody or a rapid rise in level (doubling over a 14-day period), are important. previous pregancy with severe disease titres not required Testing of fetal anemia a t 16-18 wks With Kell alloimmunisation, there is a lower threshold for specialist input because these alloantibodies can cause severe and unpredictable fetal anaemia (caused by suppressed erythropoiesis) irrespective of antibody levels and previous pregnancy outcome. Follow-up testing for lower risk alloantibodies is individualised.

35. ABO inompatibility protects against R h isoimmunization when incompatable fetal rbc enters mothers circulation they quickly combine with naturally occuring anti a anti b agglutinins an d nuetralised by sequestration in liver .

36. Alloimmunized woman In case of history o f , i n c r e a s e d t i t r e s , H ydrops start monitoring f r o m 10 wks pri o r to previous pregnancy .

37. Maternal mirror syndrome - triple edema ,polyhydrops in fetal hydrops causes mirror syndrome due to vascular changes in swollen hydropic placenta.mirror syndrome because mother develops preeclampsia with severe edema similar to fetus called Ballantyne syndrome.

38. Hydrops fetalis features Im mune hyd rops : Pr e s e n c e o f c o l l e ction o f f l u i d mor e t h a n 2 b o d y c a v i t i es . X ra y: B u d d h a p o s i t ion : S calp subcutaneous edema causing halo around the head Us s : A scites Increased AC ( Hepatomegalomegaly) P leural effusion,P ericardial effusion L arge pla c e n t a : 2nd trimister >4cm,3rd trimister>6cm P olyhydromnios Cardiomrgaly:cardiac circumference /thorasic circumference >50% CTG:Sinusoidal pattern.

39. Management of Isoimmunization Due to Other Rh Antigens This is suspected when there is past history of hydrops, neonatal jaundice and exchange transfusion. On Rh typing these mothers will be either Rh-D positive or Rh D negative with negative ICT for Rh-D antibodies. When suspected, ICT for Rh C , E, Kell and Duffy antigens is performed and a positive ICT will denote isoimmunization due to a specific antibody. The management is essentially same as with Rh-D isoimmunization (monitoring with antibody titer and MCA-PSV). The only difference is that antibody ti t r e is not very informative and management depends on the MCA-PSV. In Kell isoimmunization the fetal anemia is due to erythroid cell depression and not because of the hemolysis. However the management remains same as for Rh-D isoimmunization.

40. MCA PSV

41. W hy MCA Doppler In response to fetal anemia increase in fetal blood velocity in various vessels due to increased cardiac out and decreased blood viscosity Umbilical vessels , Desceding aorta , C C A not used MCA m o st promising ,reproducible more than 70% invasive procedure Pereira et al. in 2003, confirmed these results The MCA-PSV diagnoses fetal anemia, even in cases of Kell sensitization, in which the problem is not the hemolysis but the suppression of the erythroid precursor in the bone marrow.

42. Van Dongen et al., in this issue of the Journal, concisely confirm that MCA-PSV can be used even in cases of Kell alloimmunization. This is another advantage of using the MCA-PSV, because in cases of Kell alloimmunization, delta OD450 is not accurate. The sensitivity - 7 % to 100% operator dependant

43. Technique f o r MCA PSV An axial section of the head is obtained at the level of the sphenoid bones(BPD ) Color Doppler identifies the circle of Willis; the MCA is zoomed; Identify major anterolateral branch the color box is placed around the medial half and middle third of MCA; The MCA flow velocity waveforms are displayed and the highest point of the waveform (PSV) is measured. The waveforms should be all similar. The above sequence is repeated at least three times in each fetus Fetus resting Maternal Breath mobvememnts kept minimum Entire length of MCA near origin of internal carotid aretry (decrease false negetive ) Close to maternal skin Angle of insonation as close to 0 -15 degree Arecent meta anlsis sensitivity and specificity 86% and 71% respectively.

44. Timing and freequency Begin at 18-20 wks to 34-35wks pog In case of previous affected pregnancy or after critical titre-1:16 Threshold value of 1.5 Mom suggests fetus with mod to severe anemia One or two weekly intervals based on clinical experience and progrogression of fetal anemia using trend on mca psv and previous obstretric history. False positive rate increase after 34 wks due to augmentation of cardiac output

45. Limitations of MCA PSV Angle of insonation distal MCA - underestimate . Blood viscosity decreased sesitivity after multiple transfusions >3 Fetal cerebral hemodynamics sever ventrilogomegaly ,solid tumorsor vascular malformations Dependant on left ventricular cardiac output -fetal hydrops ,CHD Decreased specificity after 35 wks Intermittent vascular constriction over estimate .

46. Intrauterine Transfusion (IUT) The first intrauterine transfusion (IUT) occurred in 1963 by Dr Liley . IUT is considered to be most effective in management of isoimmunized pregnancy where fetus is anemic and not mature enough to be delivered. If IUT is not done, fetus is at the risk of developing hydrops and dying in utero. success rate If fetal anaemia is diagnosed early before hydropic changes sets in fetal survival is up to 80-90 % after intravascular fetal transfusion of RBCs but if hydropic changes are set in70-80% , survival reduces to 25 -35 % only.

47. Fetal anemia for a given gestational age mild (hemoglobin < 0.84 MoM ) moderate (hemoglobin < 0.65 MoM) severe (hemoglobin < 0.55 MoM) Indication of FBS/ Transfusion: Any USG findings suggestive of severe fetal anemia 4Fold rise in antibody titer level than previous titer in follow up examination Neonatal disease requiring exchange transfusion in previous pregnancy Previous IUD due to Rh disease Father-homozygous Rh positive

48. Aim of IUT Aim to raise fetal Hct 45-50% In severely anemic and Hydropic fetus Acute correction avoided Final post transfusion hct should not exceed 25% or 4 fold from pretransfusion value repeat I,UT within 48 hrs to bring to normal range,3 rd procedure after 7-10 days

49. Procedure

50. Procedure of Fetal transfusion: Performed as an outdoor procedure. After aseptic precaution A 20-22 guage, 7-inch long echo tip spinal needle is then guided into the targeted vessel under ultrasound guidance. Localzation of placenta After correct placement of needle fetal blood is aspirated for immediate Haematocrit, CBC, blood type and Rh factor Usually O Negative, collected 5days ,leukocyte depleted,Cytomegalo virus (CMV) free, HIV ,HbSAg, Hep C, tested packed Red Blood cells with hematocrit of about 80 %(to prevent over load) and irradiated ( prevent Graft-versus-host reaction)blood to preferred for the fetal transfusion.

51. Fetal anesthetic agent, if required, may be injected to induce fetal paralysis. Fetal anesthesia can be help to stop the fetal movement. This approach is not useful in cases where placenta is attached on anterior wall of uterus. Atracurium / vencuronium in the dose of 0.1 mg/kg is to be given. Volume of blood to be transfused will depend on the fetal gestation, hematocrit of the donor blood and hematocrit of fetal blood. The normograms are available to calculate the volume of blood needed to increase the fetal hematocrit to 40 % .

52. Packed blood is infused manually into the fetal circulation through a 10-ml syringe and a transfusion set. The goal is to reach a fetal Haematocrit of 40% (and up to 55% depending on the institution); the amount of blood necessary varies according to initial Haematocrit and fetal weight. To minimize potential increases in fetal cardiac over load, a transfusion Hematocrit of 80 – 90% is used, and post-transfusion fetal Haematocrit should not exceed 55%.

53. If may be difficult and in these cases, there is an option of using a free loop oumbilical cord, hepatic vein or to perform intraperitoneal transfusion. After the procedure, CTG tracings are taken and monitored for at least half an hour for any fetal heart decelerations. Antenatal coticosteroids are given to procedure if i case of fetal distress to take for emergency lscs

54. Blood should be less than 5 days old (to ensure low supernatant potassium levels), CMV negative and irradiated It should be plasma reduced (rather than in saline-adenine-glucose-mannitol [SAGM] additive solution), with a haematocrit of 0.50–0.60. Blood for neonatal small volume (‘top-up’) transfusion Blood should be ABO compatible with the neonate and mother (to avoid ABO HDFN from the woman’s anti-A or -B antibodies present), RhD negative (or RhD identical with neonate), K negative and negative for the corresponding antigen to which the woman has an antibody and cross-match compatible with the woman’s blood sample. Blood should be CMV negative but does not need to be irradiated unless the neonate has had a previous IUT and blood can be stored in SAGM (rather than plasma reduced) and be up to 35 days old (as a topup transfusion is a much smaller volume than an exchange transfusion).

55. Calculated by using the formula: Mandelbrot formula : Transfusion volume =Fetoplacental volume x (Hematocrit final-Hematocrit initial)Hematocrit in transfused blood. Fetoplacental volume = fetal weight in grams x 0.14 Amount to be transfused depends on fetal hematocrit ,estimated fetal wt,donor hct The aim is to increase hematocrit to 35–40 % in early mid-trimester and after that to 45–55 %.

56. C omplications A s it is inavasive hemotoma,hemorhage ,iud F etal bradycardia ;,fetal distress pprom P reterm labour I ncreased lscs rate

57. RCOG guidelines 2014 All women should have their blood group and antibody status determined at booking and at 28 weeks Non-invasive fetal genotyping using maternal blood is now possible for D, C, c, E, e and K antigens. This should be performed in the first instance for the relevant antigen when maternal red cell antibodies are present. For other antigens, invasive testing (chorionic villus sampling [CVS] or amniocentesis) may be considered If fetal anaemia is a concern or if invasive testing is performed for another reason (e.g. karyotyping).

58. For antibodies other than anti-D, anti-c and anti-K, the following should prompt referral to a fetal medicine specialist. A history of previous significant HDFN or intrauterine transfusion (IUT), or a titre of 32 or above, especially if the titre is rising as rising titres correlate with increasing risk and severity of anaemia. An anti-D level of > 4 iu/ml but < 15 iu/ml correlates with a moderate risk of HDFN and an anti-D level of > 15 iu/ml can cause severe HDFN. Referral for a fetal medicine opinion should therefore be made once anti-D levels are > 4 iu/ml. An anti-c level of > 7.5 iu/ml but < 20 iu/ml correlates with a moderate risk of HDFN, whereas an anti c level of > 20 iu/ml correlates with a high risk of HDFN. Referral for a fetal medicine opinion shouldMtherefore be made once anti-c levels are > 7.5 iu/ml.

59. For anti-K antibodies, referral should take place once detected, as severe fetal anaemia can occur even with low titres. The presence of anti-E potentiates the severity of fetal anaemia due to anti-c antibodies so that referral at lower levels/titres is indicated (unless the fetus has only one of these antigens). Anti-D and anti-c levels should be measured every 4 weeks up to 28 weeks of gestation and then every 2 weeks until delivery. Although anti-K titres do not correlate well with either the development or severity of fetal anaemia, titres should nevertheless be measured every 4 weeks up to 28 weeks of gestation, then every 2 weeks until delivery.

60. For all other antibodies, retesting at 28 weeks is advised with the exception of women who have a previous history of pregnancies affected with HDFN when early referral to a fetal medicine specialist is also recommended. Fetal monitoring is required (as above) once anti-K is detected. For antibodies that could potentially cause problems with cross-matching or issues with the availability of appropriate blood, discussion with the blood transfusion service is required regarding the frequency of antenatal testing. This may depend on the type of antibody as well as the likelihood of requiring blood at short notice.

61. For antibodies other than anti-D, anti-c, anti-C, anti-E or anti-K, maternity staff should liaise with their local transfusion laboratory to assess and plan for any possible transfusion requirements, as obtaining the relevant blood may take longer. Pregnant women with red cell antibodies, who are assessed as being at high risk of requiring a blood transfusion, should have a cross-match sample taken at least every week.

62. Ultrasound monitoring should be performed by a professional with appropriate expertise to reliably perform MCA Doppler assessment (see International Society of Ultrasound in Obstetrics and Gynecology practice guidelines for the use of Doppler ultrasonography in obstetrics21). If the MCA PSV rises beyond the interventional threshold then referral to a fetal medicine specialist with expertise in IUT should be made. MCA PSV monitoring is predictive of moderate or severe fetal anaemia with 100% sensitivity and a false positive rate of 12%. If monitoring of the MCA indicates anaemia (MCA PSV > 1.5 MoM), fetal blood sampling (FBS) and possibly IUT are indicated. Monitoring with MCA PSV should be used with caution after 36 weeks as its sensitivity for the detection of fetal anaemia decreases.

63. Blood should be IAT (indirect antiglobulin test) cross-match compatible with maternal plasma and negative for the relevant antigen(s) determined by maternal antibody status. K-negative blood is recommended to reduce additional maternal alloimmunisation risks. It should also be less than 5 days old and in citrate phosphate dextrose (CPD) anticoagulant, cytomegalovirus (CMV) seronegative, irradiated and transfused within 24 hours of irradiation. Blood for IUT should never be transfused straight from 4ºC storage. In exceptional cases, it will be necessary to give O RhD-positive, c-negative blood, for example in HDFN because of anti-c alloimmunisation, where giving RhD-negative blood would be harmful.

64. If maternal transfusion is required, what type of donor blood or blood components should be used? Red cell components of the same ABO group and RhD type, and that are K negative and cytomegalovirus negative should be selected.

65. Cord blood investigations RhD typing where the mother is known to have immune red cell antibodies. A positive DAT indicates that the infant’s red cells are coated with antibody but in itself cannot predict severity of haemolysis. Notably the DAT may be negative in ABO HDFN. It is therefore essential to also determine haemoglobin and bilirubin levels to ascertain the degree of anaemia and haemolysis at birth and this helps guide management .

66. Neonatal care This depends on the risk of haemolysis or anaemia conferred by the relevant red cell antibody. Regular clinical assessment of its neurobehavioural state and be observed for the development of jaundice and/or anaemia. Regular assessment of bilirubin and haemoglobin levels should be made and early discharge is not advisable. The mother should be encouraged to feed the baby regularly to guard against dehydration, since dehydration can increase the severity of jaundice. Clinicians should be aware that if bilirubin levels rise rapidly or above the interventional threshold, phototherapy and/or exchange transfusion may be required. Pregnancies complicated by red cell alloimmunisation with a minimal or no risk of fetal or neonatal anaemia require no specific treatment

67. Clinicians should be aware that some infants may develop late anaemia which is usually due to hyporegenerative anaemia. Anaemia persisting for a few weeks after birth is usually the result of passively acquired maternal antibodies causing continued haemolysis. Late anaemia may develop due to a transient suppression of neonatal erythropoiesis, itself due to transfusion. Babies who have required several IUTs are at particular risk. Affected infants have suppression of erythropoiesis with low numbers of reticulocytes despite a low packed cell volume and normal erythropoietin values. ‘Top-up’ transfusions are required only if the infant is symptomatic. There is some evidence that the need and frequency of ‘top-up’ transfusions may be decreased if recombinant erythropoietin is used.

68. Do assisted reproductive techniques (ART) increase the risk of red cell antibodies developing? There is no evidence that ART increases the risk of red cell alloimmunisation. However, if donor eggs are used for a mother with an alloantibody and the donor red cell antigen status is not known, fetal genotyping may be required. in case of repeated pregnancy losses if father is homozygous ,donor sperm can be used,PIGT can be used.

69. Future Risks A woman with a history of a pregnancy or infant affected by HDFN should be referred for early assessment to a fetal medicine specialist in all further pregnancies. Women can be advised that there are no long-term adverse health consequences associated with the presence of red cell antibodies. Clinicians should be aware that some infants may experience anaemia persisting for a few weeks following birth. Clinicians should be aware that some infants may develop late anaemia which is usually due to hyporegenerative anaemia

70. T h a n k you