OGCO-C2.7 Prevention of Rhesus sensitisation in Obstretics and Gynaecology Flashcards
What is the Ix done for rhesus sensitization?
All women booking at the antenatal clinic or MCHC or non booked pregnant women admitted to the obstretics word will have blood group (ABO and Rh) checked and those who are Rh(D) negative will have red cell antibody screening.
What is the timing for screening for Rh immunozation
1st check will be at 1st antenatal apointment
All Rh(D) negative women without anti-D antibodies will have anti-D antibody titre repeated at 28-30 weeks before routine antenatal anti-D prophylaxis (RAADP).
All Rh(D) negative women with ongoing pregnancy with anti-D antibodies will be referred to prenatal diagnosis clinic for follow up, for possible isoimmune haemolytic anemia of the fetus
If women has no anti-D antibodies at 28 weeks what is Mx?
Given one dose of anti-D (1500IU prefilled syringe) for antenatal prophylaxis at 28-30 weeks (after blood taken for anti-D antibodies titre). There is no need to check anti-D antibody titre again after routine antenatal prophylaxis has been given.
Use of RAADP should not be affected by previous anti-D Ig prophylaxis administered for a sensitizing agent in the same pregnancy
What is Rhesus management for potentially sensitizing events?
Antenatal prophylaxis (irrespective of RAADP): 1 dose of anti-D (1500IU prefilled syringe) will also be given to non sensitized Rh(D)-ve women who have
* Threatened miscarriage at or above 12 weeks gestation (consider 6 weekly injection if recurrent bleeding). In the event of further interrmittent uterine bleeding after 20 weeks, estimation of fetomamternal hemorrhage (FMH) by Kleihauer test should be carried out at 2 weekly interval
- threatened miscarriage below 12 weeks if there is heavy vaginal bleeding or associated with abdominal cramps
- antepartum haemorrhage
- CVS, amniocentesis, cordocentesis, intrauterine transfusion, shunting, laser or
any other invasive prenatal diagnostic or treatment procedures
- external cephalic version
- abdominal trauma
- fetal death
- inadvertent transfusion of Rh positive platelets to Rh negative women (need to calculate the dosage)
- inadvertent transfusion of Rh positive blood to Rh negative women (need to calculate the dosage +/- exchange transfusion versus non-intervention)
Kleihauer test should be done if the event takes place after 20 weeks gestation to estimate the amount of fetal maternal transfusion.
What is Rh management for continual uterine bleeding (same sensitizing agent)?
If continual uterine bleeding which is clinically judged to represent the same sensitizing event, with no features suggestive of a new presentation or a significant change in the pattern or severity of bleedng, such as the presence of abd pain or another clinical presentation, a dose of 1500IU anti-D Ig should be given at 6 weekly intervals. In the event of further interrmittent uterine bleeding, estimation of FMH should be carried out at 2 weekly intervals.
If the 2 weekly FMH test shows the presence of fetal cells, additional anti-D Ig should be administered to cover the volume of FMH.
The additional dose should be offerred regardless of the presence or absence of passive anti-D in maternal plasma, and FMH should be retested after 48h if anti-D Ig has been given IV, or 72h if given IM.
What is Rh management for continual uterine bleeding (snew sensitizing agent)?
If new symptoms develop suggestive of a sensitizing event in addition to continual uterine bleeding (abd pain associated with a significant change in the pattern or severity of bleeding) then it should be managed as an additional sensitizing event with an appropriate additional dose of anti-D and estimation of FMH.
Each new sensitizing event should be managed with an appropriate additional dose of anti-D regardless of the timing or dose of anti-D administered for a previous event.
What is the RhD prophylaxis after delivery?
Immediately after delivery, cord blood checked for serum bilirubin, CBP, including reticulocyte count and Rh grouping and maternal blood collected to test for Kleihauer test (preferably within 2 hours). If the baby is Rh(D) positive, she will be given anti-D prophylaxis (one dose or higher according to the results of the Kleihauer test)
Who will 1 dose prophylaxis anti-D antibody (1500IU) given to?
- Threatened miscarriage at or after 12 weeks or threatened miscarriagae with heavy vaginal bleeding or abd cramps before 12 weeks
- Ectopic pregnancy with surgical treatment
- Suction evacuation at any gestation
- Second trimester termination of pregnancy
- Molar pregnancy
What is the anti-D dosage calculation?
Dose of anti-D Ig should be calculated as 125 IU if administered IM or 100 IU if administered IV for each mL of fetal red cells detected (minimum 500IU). FMH should be retested after 48 h if anti‐D Ig has been given IV, or 72 h if given IM to check for clearance of fetal cells.
