Platelet reactivity in twin pregnancies. (February 2016) - Umazume, Takeshi
Abstract: Background: Gestational thrombocytopenia is more likely to occur in twin than singleton pregnancies. However, it is unclear whether platelets are more reactive in twin than singleton pregnancies. Methods: Changes in spontaneous platelet aggregation and concomitant fall in platelet count were examined over 90 min after blood sampling in 171 and 52 citrated whole blood (CWB) samples from 59 and 17 women with singleton and twin pregnancies, respectively. Soluble P-selectin (sP-selectin) levels in the plasma were also determined. Results: CWB 60 min after blood sampling during 2nd trimester exhibited significantly larger numbers of platelet aggregates (1297 ± 1600 vs. 497 ± 432/μl, P = 0.040) concomitant with significantly greater net decrease in platelet count (152 ± 55 vs. 115 ± 45 × 10 9 /μl, P = 0.036) in twin than singleton pregnancies, respectively. This was followed by significantly lower 3rd trimester platelet count (181 ± 43 vs. 229 ± 62 × 10 9 /l, P = 0.009) with significantly greater mean platelet volume (8.0 ± 1.2 vs. 7.1 ± 1.1 fl, P = 0.021) in twin than singleton pregnancies, respectively. The 3rd trimester sP-selectin per platelet was significantly higher in twin than singleton pregnancies. Conclusions: Platelets were more reactive in the 2nd trimester of twin than singleton pregnancies. This enhanced platelet reactivity may explain the decreased platelet count in the 3rd trimester of twin pregnancy. Highlights: Gestational thrombocytopenia is likely to occur in twin pregnancy. Spontaneous platelet aggregation (SPA) can occur in stirred citrated whole blood. SPA of 2nd trimester blood was more active in twin than in singleton pregnancies. SPA was associated with decrease in platelet counts. Enhanced platelet reactivity may explain thrombocytopenia in twin pregnancy.