Thrombocytopenia in pregnancy is defined as a platelet count <100 × 10⁹/l. We undertook a 5-year [2008–2012] retrospective case note review of 34 patients with thrombocytopenia in pregnancy managed in an Obstetric Medicine Clinic.

In 7, the diagnosis was made at booking [of whom 3 were known to have idiopathic thrombocytopenia [ITP] pre-pregnancy], 4 in 2^nd trimester and 23 in 3^rd trimester; platelet ranges 25–96, 50–86 and 34–97 × 10⁹/l respectively. The 31 in whom there was not already a diagnosis, were investigated for obstetric and non-obstetric causes of thrombocytopenia. No new definitive diagnoses were made; working diagnosis was therefore ITP.

Intrapartum management was influenced in 7 patients [21%] – 2 underwent emergency Caesarean Section (contraindication to fetal blood sampling), 1 had forceps instead of ventouse, 4 unable to have regional anaesthesia. All cord platelet measurements were normal. Only 1 woman had thrombocytopenia postnatally; subsequent bone-marrow aspirate was normal.

Prompt identification and appropriate treatment of thrombocytopenia in pregnancy could improve pregnancy outcomes.