Platelet indices in late preterm newborns

Perinatal factors affecting platelet parameters in late preterm and term neonates

Platelets parameters including platelet count (PLT), plateletcrit (PCT), mean platelet volume (MPV) and platelet distribution width (PDW) are associated with various physiological and pathological functions in various disease. However, few studies have addressed whether perinatal factors may be associated with platelet parameters at birth in a large cohort of late preterm and term neonates. The aim of this study to investigate perinatal factors affecting platelet parameters in late preterm and term neonates. We retrospectively investigated platelet parameters including PLT, PCT, MPV, and PDW on the first day of life in 142 late preterm and 258 term neonates admitted to our NICU from 2006 through 2020. PLT, MPV, PCT, PDW on Day 0 did not significantly differ between the two groups. In term neonates, multivariate analysis revealed that PCT correlated with being small for gestational age (SGA) (β = -0.168, P = 0.006), pregnancy induced hypertension (PIH) (β = -0.135, P = 0.026) and male sex (β = -0.185, P = 0.002). PLT was associated with SGA (β = -0.186, P = 0.002), PIH (β = -0.137, P = 0.024) and male sex (β = -0.166, P = 0.006). In late preterm neonates, multivariate analysis revealed that PLT were associated with PIH, whereas no factors associated with PDW and MPV were found. In all patients studied, chorioamnionitis (CAM) was significantly associated with MPV (CAM = 10.3 fL vs. no CAM = 9.7 fL, P<0.001). Multivariate analysis showed that SGA, male sex and PIH were associated with PCT and PLT. This study demonstrates that different maternal and neonatal complications affect platelet parameters in late preterm and term neonates.

[Reference ranges of platelet and related parameters within 24 hours after birth in preterm infants with different gestational ages]

OBJECTIVE

To study the reference ranges of platelet and related parameters within 24 hours after birth in preterm infants with different gestational ages.

METHODS

According to the inclusion and exclusion criteria, a retrospective analysis was performed for the chart review data of 1 070 preterm infants with a gestational age of 23-36⁺⁶ weeks who were admitted to the neonatal intensive care unit from January to December in 2018. The reference ranges of platelet parameters were calculated for the preterm infants within 24 hours after birth.

RESULTS

There were no significant differences in platelet count (PLT) and plateletcrit (PCT) among the preterm infants with different gestational ages (P>0.05). The late preterm infants (34-36⁺⁶ weeks; n=667) had significantly lower mean platelet volume (MPV) and platelet distribution width (PDW) than the extremely preterm infants (23-27⁺⁶ weeks; n=36) and the early preterm infants (28-33⁺⁶ weeks; n=367) (P<0.05). There were no significant differences in these platelet parameters between the preterm infants with different sexes (P>0.05). The reference ranges of platelet parameters in preterm infants were calculated based on gestational age. The reference ranges of PLT and PCT were (92-376)×10⁹/L and 0.1%-0.394% respectively, for the preterm infants with a gestational age of 23-36⁺⁶ weeks. The reference ranges of MPV and PDW were 9.208-12.172 fl and 8.390%-16.407% respectively, for the preterm infants with a gestational age of 23-36⁺⁶ weeks; the reference ranges of MPV and PDW were 9.19-11.95 fl and 9.046%-15.116% respectively, for the preterm infants with a gestational age of 34-36⁺⁶ weeks.

CONCLUSIONS

The MPV and PDW of preterm infants with different gestational age are different within 24 hours after birth, and it is more helpful for clinical practice to formulate the reference range of MPV and PDW according to gestational age.