Decrease Rate of Platelet Count as a Marker for Complications of Preeclampsia: A Cross-Sectional Study

BackgroundThrombocytopenia is considered a sign of maternal organ damage of preeclampsia. However, platelet count distribution during pregnancy shifts downward even in uncomplicated women, and platelet counts in some uncomplicated women falls below the cutoff value of thrombocytopenia. Thus, not only absolute platelet counts number but also platelet count reduction rate may relate with adverse outcomes of preeclampsia. This study aimed to evaluate whether the overall platelet count reduction rate was associated with adverse outcomes of preeclampsia. MethodsThis retrospective study included 240 singleton pregnant women with preeclampsia. Overall platelet count reduction ≥30.0% was used as a cut-off value because 10–20% platelet counts reduction can be observed in uncomplicated pregnancy. The association between the overall platelet count reduction from the first trimester ≥30.0% and adverse outcomes; severe hypertension, uteroplacental dysfunction, maternal organ damage except for thrombocytopenia, and preterm delivery <34 gestational weeks were analyzed. Moreover, subgroup analysis was conducted in women without thrombocytopenia.ResultsA total of 95/240 (39.6%) of women had ≥30.0% of overall platelet count reduction from the first trimester. The incidences of maternal organ damage except for thrombocytopenia (12.4%, 22.1%; p = 0.047), and preterm delivery <34 gestational weeks (30.3%, 48.4%; p = 0.005) were higher in women with ≥30.0% of overall platelet count reduction than those otherwise. Even in women without thrombocytopenia (platelet counts ≥150 × 109/L), severe hypertension (66.2%, 85.4%; p = 0.018), and preterm delivery <34 gestational weeks (30.8%, 51.2%; p = 0.017) were more frequently observed in women with ≥30.0% of overall platelet count reduction than those otherwise.ConclusionsA ≥30.0% of overall platelet count reduction from the first trimester was associated with adverse outcomes of preeclampsia even in women without thrombocytopenia.