Use of mean platelet volume in the assessment of intrauterine infection in newborns with combined thrombocytopenia and leukopenia at birth.

Intrauterine stress can be reflected on hematological disturbance at birth. Thrombocytopenia and leukopenia may be a result of exposure to maternal hypertensive disorders but may also indicate fetal inflammatory response to intrauterine infection, prompting empiric antibiotics use during the initial assessment after birth. Emerging data suggest long-term adverse health outcomes associated with antibiotics exposure early in life. In this report, we sought to assess the use of mean platelet volume (MPV) at birth in predicting fetal inflammatory response in newborns with combined thrombocytopenia and leukopenia. This is a retrospective study from a single academic medical center. Data were collected prospectively on all newborns with thrombocytopenia and leukopenia within the first 24 h of life. The primary outcome was a composite of fetal tachycardia, premature preterm rupture of membrane with preterm labor, and histological evidence of chorioamnionitis/funisitis/villitis on placental pathology reports evaluated using a multiple logistical regression analysis. The prevalence of combined thrombocytopenia and leukopenia was 5.8% (99 out of 1693 newborns) during the study period. The prevalence was highly associated with gestational age ( = 0.873). Twenty-four (32.4%) had abnormal MPV values at birth, defined as MPV > 9 or < 7 fL. Newborns with abnormal MPV had lower platelet counts and were more likely to have I:T ratio ≥0.2. In a univariate analysis, abnormal MPV (OR: 6.205, 95% CI: 1.923-20.022,  = .002), I:T ratio ≥0.2 (OR: 8.462, 95% CI: 1.396-51.281,  = .02), and platelet counts (OR: 98.4, 95% CI: 96.9%-99.9%,  = .035) were each significantly associated with a positive composite outcome. In a multivariate analysis, only abnormal MPV remained significantly associated with an increased likelihood of having a positive composite outcome, with an OR of 3.922 (95% CI: 1.094-14.06,  = .036). MPV may be a more reliable marker than I:T ratio ≥0.2 for fetal inflammatory response in newborns with combined thrombocytopenia and leukopenia during the initial assessment of intrauterine infection. Future prospective studies are required to confirm findings from this report.