All women who delivered from 1/2000 through 12/2002, with the discharge diagnosis of mild preeclampsia, severe preeclampsia (including HELLP and eclampsia), and preeclampsia superimposed on chronic hypertension were identified through the Perinatal Database. Platelet counts (PC) for each patient, from one month prior to the delivery admission, until hospital discharge, were analyzed. The number of PC determinations per parturient was determined. For each diagnosis, the positive predictive value (PPV) of an initial PC > 150,000/mL for maintaining subsequent PC > 80,000/mL, as well as the PPV of the PC prior to initiation of neuraxial analgesia was calculated. The median time interval from the closest PC determination to initiation of neuraxial analgesia was calculated.