Rhesus Disease

Question 1

What is rhesus disease?

Answer 1

Development of Rh Ab in Rh- mother after exposure to Rh+ baby. (usually D)

Question 2

What is the aetiology of rhesus disease?

Answer 2

Sensitising event esposes mother to Rh + blood. Maternal Ab develop and subsequent pregnancies with RhD+ fetus, maternal IgG cross placenta and form cmplexes with fetal cells, destroying them. Sensitising events include APH, miscarriage, ectopic pregnancy, TOP, invasive prenatal testing.

Question 3

What are the RFs of Rhesus Disease?

Answer 3

Previous pregnancy with insufficient or none andt D prophylaxis, previous blood transfusion D+

Question 4

What is the epidemiology of Rhesus Disease?

Answer 4

1% without prophylaxis.

Question 5

What are the Hx/Exam of Rhesus Disease?

Answer 5

Picked up on routine screening, patient may be aware from previous pregnancies. Poor obstetric hx.

Question 6

What is the pathology of Rhesus Disease?

Answer 6

IgG against RhD+ cells cross placenta. Anaemia reached, then hyperbiliruminaemia, subsequent hydrops fetalis (fetal HT associated with accumulation of fluid SC and in bod ycomparments.)

Question 7

What are the Ix of Rhesus Disease?

Answer 7

Monitoring of maternal Ab levels. Once threshold reached for anaemia, monitor in a fetal medicine centre with USS, markers of anaemia i.e. MCA doppler. Monitoring mat lso include measurement of amniotic BR or cordiocentesis.

Question 8

What is the Mx of Rhesus Disease?

Answer 8

Prevent: Anti-D Ig prophylaxis required in all RhD- mothers in UK, at 28/40 and 34/40. Follwing sensitizing event, and after delivery if baby RhD+.

Rh immunisaiton in current pregnancy: may necessitate fetal blood transfusion, and exchange transfusion after delivery.

Question 9

What are the complications/ prognosis of Rhesus Disease?

Answer 9

Hydrops fetalis, Iudeath, neonatal death, kernicterus (hyperBR with brain involvement).