Thrombocytopenia

Question 1

Causes of fetal thrombocytopenia

Answer 1

NAIT (3% of all, 30% of severe)
Congenital infections
Chromosomal abnormalities 
Maternal autoimmune disease (itp , sle)
Severe resus haemolytic disease
Congenital syndromes

Question 2

NAIT

Answer 2

1:1000
Incompatibility between parents for platelet specific antigens
Maternal antibodies (igg) against human platelet antigens that she lacks
Bind incompatible fetal platelets and promote their clearance from the fetal circulation and results in fetal thrombocytopenia

Question 3

NAIT effects on infants

Answer 3

Bleeding, bruising
ICH (10-20% if platelets <50, 75% in the antenatal period/before 30 weeks
Death
Similar pres innpregnancies (80% recurrence)
Can occur in first pregnancy (20%)

Question 4

HPA causing NAIT

Answer 4

HPA-1:white
HPA -5b/b: African
HPA-4: Asian

Question 5

NAIT treatment

Answer 5

IVIG
Steroids
FEtal blood sampling
Fetal platelet transfusion 
Mode of delivery (?elcs)

Question 6

NAIT diff from Rh

Answer 6

Primip 
Similar each pregnancy 
Invasive testing 
IVIG
IUT probably harmful
Screening rare
No prophylaxis

Question 7

Rh different from NAIT

Answer 7

Multips
Worse each preg
NIPT
IVIG rarely
IUT tx of choice
Effective screening
Effective prophylaxis

Question 8

Tests for thrombocytopenia

Answer 8

Reticulocyte count
Direct anti globulin test
Coag screen
Lfts 
Lupus anticoagulant, cardiolipin, and beta-2 glycoprotein igG and igM abs
SLE serology
Tfts 
Viral screen (hcv, cmv, hbv, hiv)

Question 9

Monitoring platelets in ITP

Answer 9

Fortnightly

If < 80, weekly testing after 34/40

Question 10

Treatment of thrombocytopenia

Answer 10

Plt 50-80: steroids 10mg/day for 10 days before delivery
Can consider IVIG
Treat itp earlier if indicated or level super low

Question 11

Newborn of itp mum

Answer 11

0.5-1.5% ICH
<50: 10%
<20: 5%

Question 12

TTP etiology

Answer 12

Deficiency of ADAMTS13

Congenital or acquired

Question 13

Management of TTP & HUS

Answer 13

Plasma exchange
Given until platelets >150 for 3/7 and normal LDH
Aspirin and LMWH

Question 14

Sickle cell disease

Answer 14

Single gene AR
Most common inherited condition
Common in non-white
Polymerizartion of abnormal hb in low oxygen conditions
Cells prone to breakdown—anaemia

Question 15

Maternal risks in sickle disease

Answer 15

Painful crisis
Increased hospitalisation
Infection
Vte 
Aph 
?pet
Mat mortality

Question 16

Neonatal risks sickle disease

Answer 16

Increased pnmr
Prem
Fgr
Scd 
? Increased miscarriage

Question 17

Thalassemia major

Answer 17

Defective beta globin synthesis

7+ transfusions per year

Question 18

Beta thalassemia trait

Answer 18

Mild to moderate microcytic anaemia

Question 19

Pathophys of haemoglobinopathy

Answer 19

Imbalance of globin chains causes haemolysis and impairs erythropoiesis

Question 20

B thalassemia major complications

Answer 20

If no iron chelation: die second decade

If inadequate: cardiomyopathy, cirrhosis, diabetes, hypothalamic hypogonadism, hypothyroidism and osteoporosis

Question 21

Haemoglobinopathy screening indications

Answer 21

-mcv < 80, a mch mass of less than 27 and a normal ferritin
OR
-high risk features (ethnicity, fam hx, partner of carrier, consanguinity)