[Platelet count and hematic punction with epidural block in obstetrics].

Introduction: The reference value for and the significance of mild thrombocytopenia associated with pregnancy remain undetermined, and therefore the timing, validity and meaning of coagulation tests before a regional block may vary.

Objective: To determine whether the incidence of bloody puncture is related to preoperative platelet count performed just before an epidural block, to review the incidence of hemorrhagic complications and to determine whether such complications are related to preoperative platelet count.

Methods: We carried a retrospective study of computer records for 1,168 patients given regional blocks to control pain during labor. A blood sample was obtained to assess the platelet count immediately before the block; we then analyzed the correlation between the incidence of bloody puncture and platelet count, with the patients distributed in 4 groups according to the latter.

Results: The platelet count of most patients fell between 150,000 and 250,000/mm3. The second largest group had counts between 100,000 and 150,000 platelets/mm3, which would constitute mild thrombocytopenia in non-pregnant patients. Seventy-two bloody punctures were observed, for an incidence of 6.16%, and the incidence was significantly higher in the group of patients with over 350,000 platelets/mm3 (p < 0.05). No severe obstetrical complications, such as obstetric hysterectomy or severe postpartum bleeding occurred. Nor were there cases of epidural hematoma.

Conclusions: A complete clinical history must be obtained during the anesthetist's interview with the patient in the last month of pregnancy, and detailed information on the risk of regional blocks during labor must be offered. When blood tests at the time of the interview are normal and the clinical history indicates low risk, repeating tests immediately before the block is unjustified, provided the clinical situation does not change.