The correlation between chorioamnionitis-induced abnormal placental microvessel and platelet metabolism of preterm infants

Abstract

Objective To observe the effect of chorioamnionitis on placental microvessel and platelet metabolism in premature and the correlation between them. Methods With clinical randomized controlled trial (RCT), the cases were matched by 11 according to gestational ages and divided into 2 groups according to the placental pathology results: chorioamnionitis group and control group, 32 cases in each group.Dates were obtained for preterm infants (gestational age<37 weeks) admitted to the Department of Neonatology at Guangdong Women and Children Hospital, born between June and December 2016.The platelet parameter [platelet count (PLT), mean platelet volume (MPV), platelet distribution width (PDW), plateletcrit (PCT)], birth weight, thrombocytopenia, hemorrhage complication, miscrovascular density (MVD) in placenta, platelet activating factors (CD62p, CD63) and thrombopoietin (TPO) in preterm infants were recorded and compared. Results In chorioamnionitis group, the infant birth weight[(1.90±0.41) kg vs.(2.31±0.62) kg] and the PLT in 72 hours [<24 h (197.97±63.43)×109/L vs.(266.34±69.92)×109/L; 24-72 h (202.28±29.70)×109/L vs.(256.38±69.96)×109/L] were significantly lower compared with the control group, and the differences were statistically significant(all P<0.05). The incidence of early thrombocytopenia(37.50% vs.9.38%), intracranial hemorrhage(40.62% vs.15.63%), MPV [(8.73±0.89) fL vs.(8.27±0.64) fL] and PDW[(59.46±5.90)% vs.(55.20±5.37)%] in 24 hours were significantly higher in chorioamnionitis group, and the differences were statistically significant (all P<0.05). The placental MVD in chorioamnionitis group significantly decreased[(9.08±1.35)% vs.(12.89±1.36)%, P<0.05 ]. The level of CD62p, CD63 and TPO in umbilical cord blood were significantly higher in chorioamnionitis group[(25.37±5.20)% vs.(10.35±2.94)%, (9.49±1.58)% vs.(4.04±1.21)%, (271.08±197.22) μg/L vs.(141.87±78.10) μg/L, all P<0.05]. The placental MVD was positively associated with PLT (r=0.74, P<0.05) and negatively associated with CD62p, CD63 and TPO among infants with chorioamnionitis (r=-0.64, -0.44, -0.44, all P<0.05). Conclusions The chorioamnionitis may decrease the MVD in placenta and activate platelet in fetal circulation, damaged placental microvessel may activate platelet further. Key words: Chorioamnionitis; Platelet; Platelet activation; Placenta; Infant, premature