Immune Thrombocytopenia and Pregnancy Clinical Presentation

Updated: Oct 09, 2015
  • Author: Muhammad A Mir, MD, FACP; Chief Editor: Srikanth Nagalla, MBBS, MS, FACP  more...
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Pregnant women with immune thrombocytopenic purpura (ITP) can be asymptomatic or can present with a history of easy bruisability, bleeding into the mucous membranes (epistaxis or gingival bleeding), or petechiae. They may have a history of menorrhagia or menometrorrhagia prior to pregnancy.

A maternal history of delivering a term newborn with thrombocytopenia, visceral or intracranial hemorrhage, or spontaneous or prolonged bleeding after venipuncture or circumcision raises suspicion for neonatal alloimmune thrombocytopenia (NAIT). However, about 50% of neonates with NAIT are first-born children and thus are delivered to women whose risk for the disorder is previously unrecognized and unknown. [13, 14]

Case history

A woman is 24 years old. She has been pregnant four times and given birth once (G4 P1). She has had zero spontaneous abortions (SAB0) and two elective abortions (EAB2). She is part Hawaiian and part Samoan and was referred for twice-weekly antepartum testing due to a prior stillbirth at 31 weeks' estimated gestational age. A specific cause of her fetal demise was never determined. Chromosome analysis revealed a normal male (46, XY) pattern. Placental pathology was normal, and an autopsy was not performed.

Her pregnancy and antepartum testing results are normal until 35 and 5/7 weeks' estimated gestational age (see images below). This woman is admitted for prolonged fetal monitoring, the findings of which are completely normal. She is discharged home later that day.

Immune thrombocytopenia. Nonstress test 1 week bef Immune thrombocytopenia. Nonstress test 1 week before delivery showing a normal reactive fetal heart rate pattern.
Immune thrombocytopenia. Nonstress test 4 days bef Immune thrombocytopenia. Nonstress test 4 days before delivery showing a reactive fetal heart rate with an unusual pseudosinusoidal pattern that lasted 9 minutes.

She presents 4 days later with 2 days of decreased fetal movement. Fetal heart tones cannot be auscultated, and an ultrasound confirms an intrauterine fetal demise. Labor is induced, and she delivers a 2729-g male fetus. Autopsy demonstrates a large subdural hemorrhage surrounding the brain and spinal cord (54 g) (see images below).

Immune thrombocytopenia. Neonatal brain at autopsy Immune thrombocytopenia. Neonatal brain at autopsy showing extensive subdural hemorrhage.
Immune thrombocytopenia. Neonatal spine at autopsy Immune thrombocytopenia. Neonatal spine at autopsy showing extensive hemorrhage at base of spine.

The woman's blood is sent for platelet antigen typing. Her platelet-associated immunoglobulins are high, at 7.5 (reference range 0-4.3). She tests positive for HPA-1a, the platelet-specific antigen implicated in most cases of NAIT (in whites). The father of the baby declines to have his blood drawn; therefore, platelets from the father cannot be tested with the mother's serum. Thus, these studies do not support a diagnosis for NAIT, but they do not exclude it either because many different platelet antigens exist. This mother is of Hawaiian, Samoan heritage, and different platelet antigens (not HPA-1a) probably are significant in nonwhite ethnic groups. HPA-4 has been shown to be important in NAIT in Japanese women.

Therefore, when the woman presents 2 years later pregnant with a new partner, the new father's platelets are tested against the mother's serum to verify that no antibodies in the maternal serum will react to paternal platelets. No antiplatelet antibodies are present, and she has an uncomplicated pregnancy delivering a full-term healthy infant.



Most women with ITP have normal findings on physical examination (splenomegaly is absent). Petechiae can be identified in the presence of severe thrombocytopenia.

Newborns with NAIT may have normal findings on physical examinations, or they may have a cephalohematoma, ecchymoses over the presenting part, and generalized petechiae (see images below).

Immune thrombocytopenia. An infant born with neona Immune thrombocytopenia. An infant born with neonatal lupus syndrome and severe thrombocytopenia. Note extensive bruising and petechiae.
Immune thrombocytopenia. An infant born with a cep Immune thrombocytopenia. An infant born with a cephalohematoma.


Women with ITP have an autoimmune disease and produce immunoglobulin to their own cell surface platelet antigens. Platelets coated with IgG autoantibodies undergo accelerated destruction, predominately in the spleen and liver, resulting in thrombocytopenia.

NAIT occurs when the mother is exposed to fetal platelets with incompatible paternally derived cell surface antigens. The mother's response to the foreign antigens is to produce immunoglobulin. This is initially immunoglobulin M, and the large size of this molecule prevents transplacental passage. Subsequently, the mother produces immunoglobulin G. The smaller size of this molecule permits passage across the placenta, resulting in the destruction of fetal platelets and neonatal thrombocytopenia.