Thrombocytopenia during pregnancy

1. Thrombocytopenia
during pregnancy
Prof. Aboubakr Elnashar
Benha University Hospital, Egypt
Aboubakr Elnashar

2. Causes of thrombocytopenia in pregnancy
 Spurious result (reduced platelets on automated
Coulter counter because of platelet clumping or
misreading of large immature platelets as red cells)
 Gestational thrombocytopenia
 ITP
 PET and Haemolysis, HELLP syndrome
 DIC
 Sepsis
 Haemolytic uraemic syndrome (HUS)/thrombotic
thrombocytopenic purpura (TTP)
HIV, drugs and infections (e.g. malaria)
SLE and APS
Bone marrow suppression. Aboubakr Elnashar

3. Incidence
5-10% of pregnant women
Pregnancy-associated’ or ‘gestational’
thrombocytopenia: 75%
Chronic ITP:
 usually affects young women (female to male ratio
= 3:1)
quite commonly encountered in pregnancy
1- 2 in 10,000 pregnancies.
Aboubakr Elnashar

4. Alloimmune thrombocytopenia
fetal disorder
caused by fetomaternal incompatibility for platelet
antigens (similar to Rhesus haemolytic disease of
the newborn).
no maternal symptoms and the mother is not
thrombocytopenic.
The condition develops in utero
affects all children including the firstborn, but is
usually (except in the case of subsequent siblings)
diagnosed after birth.
The incidence: 1 in 2000
10% of all cases of neonatal thrombocytopenia.
Aboubakr Elnashar

5. Clinical features
Gestational thrombocytopenia
benign condition
even if the platelet count falls to <100 × 109/L: no
adverse consequences for mother or baby.
Aboubakr Elnashar

6. ITP:
Haemorrhage is unlikely with platelet counts >50 ×
109/L
 spontaneous haemorrhage without surgery is
unlikely with counts >20 × 109/L.
Patients may present with
skin bruising or
gum bleeding, but
severe haemorrhage is rare.
isolated thrombocytopenia without any associated
haematological abnormality.
no splenomegaly or lymphadenopathy.
Aboubakr Elnashar

7. Thrombocytopenia in the first half of pregnancy
 less likely to be due to the pregnancy itself and
should alert the clinician to a possible diagnosis of
ITP.
Aboubakr Elnashar

8. Pathogenesis
Gestational thrombocytopenia
The platelet count tends to fall progressively during
normal pregnancy
 in 5% to 10% of women the count will reach
thrombocytopenic levels (50–150 × 109/L) by term.
Aboubakr Elnashar

9. ITP
Autoantibodies against platelet surface antigens:
peripheral platelet destruction by the
reticuloendothelial system, particularly the spleen.
Aboubakr Elnashar

10. Diagnosis
ITP
By exclusion of other causes of thrombocytopenia,
e,g. infection, PET
 Bone marrow: normal or megakaryocytic
bone marrow examination is not necessary in
pregnancy in cases of isolated thrombocytopenia
unless it is severe (platelet count <30 × 109/L).
Antiplatelet antibody determination:
not readily available
not helpful in the diagnosis of ITP in pregnancy
{absence of antiplatelet antibodies does not exclude
the diagnosis of ITP}.
Aboubakr Elnashar

11. Effect of pregnancy on ITP
No effect on the course of ITP
Anxieties arise around the time of
delivery{possible bleeding associated with vaginal
and abdominal delivery and regional anaesthesia
and analgesia}.
Aboubakr Elnashar

12. Effect of ITP on pregnancy
Maternal:
Capillary bleeding and purpura: unlikely with a
platelet count of >50 × 109/L,
spontaneous mucous membrane bleeding: not a
risk with platelet counts >20× 109/L.
Aboubakr Elnashar

13. Foetal:
Antiplatelet IgG can cross the placenta: fetal
thrombocytopenia.
Accurate prediction of the fetal platelet count from
maternal platelet count
antibody level or
splenectomy status is not possible: it is difficult to
predict which fetuses will be affected.
The level of risk to the fetus, which has been
overestimated in older studies, is small, in contrast
to the fetal risk in alloimmune thrombocytopenia
The risk of fetal platelet counts <50 × 109/L:
5%- 10%
10–15% in women known to have ITP before
pregnancy and in those with symptomatic ITP in the
index pregnancy. Aboubakr Elnashar

14. The incidence of antenatal or neonatal intracranial
haemorrhage in women with ITP:
 0% to 1.5%
lowest in the absence of maternal symptoms or a
history of ITP prior to the index pregnancy.
Best predictors of severe neonatal
thrombocytopenia: previously affected child, and
the incidence of serious haemorrhage in the fetus
and neonate is low.
Aboubakr Elnashar

15. Management
Gestational thrombocytopenia
benign condition requires no intervention.
Aboubakr Elnashar

16. ITP
Maternal considerations
 Exclude associated conditions such as SLE or
APS.
The platelet count monitored: monthly and then
more frequently in the third trimester: therapy can
be instituted if required prior to delivery.
Treatment is only required in the first and third
trimesters if:
– The woman is symptomatic with bleeding
– The platelet count is <20 × 109/L
– The count needs to be increased prior to a
procedure such as CVS.
Aboubakr Elnashar

17. Counts<50×109/L: even in the absence of bleeding
prophylactic treatment prior to delivery.
Counts 50 to 80×109/L:
treatment prior to delivery in order to facilitate safe
administration of regional analgesia/anaesthesia.
CS:
only required for obstetric indications
Epidural and spinal anaesthesia:
safe with stable counts >75 to 80 × 109/L.
Bleeding time:
does not predict haemorrhage and is not indicated.
Aboubakr Elnashar

18. Corticosteroids:
first-line therapy
Dose:
•outside pregnancy: high doses (60–80 mg/day, 1
mg/kg/day) of prednisolone are usually given for
newly diagnosed ITP
•in pregnancy: lower doses (20–30 mg/day), which
are safe and effective.
•Following this, the dose may be weaned to the
lowest that will maintain a satisfactory (>50 × 109/L)
maternal platelet count.
Aboubakr Elnashar

19. Anti-D immunoglobulin therapy
given as an intravenous bolus
raise platelet counts in non-splenectomised
rhesus-positive women.
by creating a decoy to competitively inhibit the
destruction of antibody-coated platelets.
 Doses:
50 to 70 g/kg.
safe and effective in the second and third
trimesters.
The baby should be monitored for neonatal
jaundice, anaemia, and direct antiglobulin test
positivity after delivery.
Aboubakr Elnashar

20. Splenectomy
should be avoided in pregnancy if possible
may be necessary in extreme cases. Ideally it
should be performed in the second trimester
can at this stage be performed laparoscopically.
Women with ITP who have previously been treated
with splenectomy should continue penicillin
prophylaxis throughout pregnancy.
Aboubakr Elnashar

21. Other options for women who fail to respond to
oral prednisolone and IVIg:
i.v. methylprednisolone
azathioprine or ciclosporin.
Although not recommended, danazol and
vincristine have been successfully used for severe
resistant cases in pregnancy.
Aboubakr Elnashar

22. Platelet transfusions
as a last resort for bleeding or prior to surgery
will increase antibody titres and do not result in a
sustained increase in platelet counts.
Aboubakr Elnashar

23. Fetal considerations
Transfer of IgG increases at the end of pregnancy
and the baby is not at risk of bleeding before labour
and delivery: no place for serial fetal blood samples
earlier in gestation.
CS: only indicated for obstetric reasons {No
evidence that CS reduces the incidence of ICH, or
that it is less traumatic for the fetus than vaginal
delivery.
The risk of fetal blood sampling via cordocentesis
(cord spasm, haemorrhage from the cord puncture
site) is similar (or even higher in thrombocytopenic
fetuses) to the risk of intracerebral haemorrhage
(ICH).
Aboubakr Elnashar

24. Neonate:
Cord platelet count
determined immediately after delivery
 platelet count only reaches a nadir after two to five
days in affected infants {when splenic circulation is
established}: most hemorrhagic events occur 24 to
48 hs after delivery at the nadir of the platelet count:
monitoring is necessary over this time.
IVIg indications
Bleeding
severe thrombocytopenia
platelet count of the cord blood is low (<20 ×
109/L).
Aboubakr Elnashar

25. Immune thrombocytopenia
The diagnosis of ITP is one of exclusion and
should only be made once other causes of
thrombocytopenia have been excluded.
Bleeding is unlikely if the platelet count is >50 ×
109/L.
The risk of serious thrombocytopenia and
haemorrhage in the neonate from transplacental
passage of antiplatelet IgG is low.
CS is only required for obstetric indications
Epidural and spinal anaesthesia/analgesia are safe
with stable counts >75 to 80 × 109/L.
Treatment, if required, should be with
corticosteroids or IVIg.
Aboubakr Elnashar

26. ThankYou
Aboubakr Elnashar