The predictive value of early-pregnancy mean platelet volume for preeclampsia: A meta-analysis

Preeclampsia is a hypertensive disorder of pregnancy that affects 3-7% of pregnancies globally and is a leading cause of maternal mortality worldwide. Early prediction is crucial for improving maternal and fetal outcomes, but it remains a significant challenge. During pregnancy, hormonal and immunological changes create a hypercoagulable, pro-inflammatory state that leads to endothelial injury, increased platelet consumption, and the release of larger, newly produced and activated platelets, resulting in elevated mean platelet volume (MPV).

This meta-analysis aimed to quantify the association between MPV measured in early pregnancy and the subsequent development of preeclampsia, differentiating between its subtypes. A systematic search was conducted in five databases, namely: PubMed, Cochrane Library, Scopus, Embase, and Web of Science up to July 2025. The study was registered in PROSPERO (CRD420251091010). Eligible studies included data on MPV measurements in pregnant women before 20 weeks of gestation who were later diagnosed with or without preeclampsia. Following data extraction, random effects (network) meta-analysis models were performed to calculate the pooled mean difference (MD) and ratio of means (ROM) in MPV between women who developed preeclampsia and normotensive controls. Subgroup analyses were performed for early-onset vs. late-onset and severe vs. mild preeclampsia.

Twenty studies involving 3050 preeclamptic patients and 12 522 normotensive controls were included. Women who later developed preeclampsia-irrespective of their preeclampsia subgroups-had higher MPV values in early pregnancy (before 20 weeks of gestation) compared to controls, with a pooled MD and ROM of +0.5681 fL [95% confidence interval (CI): +0.2144 to +0.9217; p = 0.0016] and 105.83% (95% CI: 102.11-109.69%; p = 0.0019), respectively. Subgroup analyses indicated a stronger association in more severe forms of the disease, with a greater MD observed in early-onset preeclampsia (MD = +0.6943 fL, 95% CI: -0.2361 to +1.6246, p = 0.1436; ROM: 107.44%; p = 0.1684) and severe preeclampsia (MD = +0.4201 fL, 95% CI: +0.1210 to +0.7192, p = 0.0059; ROM: 104.26%; p = 0.0064) compared to their controls.

Elevated MPV in early pregnancy is associated with an increased risk of developing preeclampsia, particularly its severe and early-onset forms.