Early-Onset Preeclampsia-Derived hUC-MSCs Exhibit Accelerated Initial Culture Kinetics Without Sustained Growth Advantage: A Comparative In Vitro Study.

Preeclampsia (PE) is a pregnancy-related disorder associated with significant maternal and fetal morbidity, and intrauterine conditions may influence the biological behavior of human umbilical cord (UC)-derived mesenchymal stem cells (hUC-MSCs). However, comparative data between early-onset PE (EOPE) and late-onset PE (LOPE) remain limited. This study aimed to compare the in vitro growth kinetics of hUC-MSCs derived from pregnancies complicated by EOPE and LOPE. In this comparative in vitro study, UC samples (n = 66) were classified into three groups according to the maternal clinical condition: control (n = 22), EOPE (n = 22), and LOPE (n = 22). Cells were isolated using a mechanical explant method and cultured under standard conditions. Culture parameters, including cell-outgrowth time, time to 90% confluency (P 0), first passage duration (P 1), and total culture duration (P 0+P 1), were recorded. Population doubling time (PDT) was calculated using both outgrowth-adjusted and P 1-based approaches, and phenotypic characterization was performed by flow cytometry. Cell-outgrowth time did not differ significantly among the groups (p = 0.930). P 0 duration differed significantly among the groups (p < 0.001). EOPE-derived cells exhibited a shorter P 0 duration (19.00 ± 2.19 days) than both control-derived cells (21.65 ± 1.63 days; Tukey-adjusted p = 0.0004) and LOPE-derived cells (20.71 ± 2.35 days; Tukey-adjusted p = 0.0266). P 1 duration and total culture duration did not differ significantly among the groups (p = 1.000 and p = 0.090, respectively). The outgrowth-adjusted group-level PDT estimate was lower in EOPE (16.6 h) than in LOPE (18.4 h) and controls (19.1 h), whereas the P 1-based PDT estimates were closely similar across the groups (~32 h). Total cell yield and viability were numerically similar across the groups. These findings indicate that EOPE-derived hUC-MSCs exhibit an early culture-specific kinetic difference, predominantly reflected by a shorter P 0 duration, without a sustained difference in subsequent P 1 expansion or total culture duration. The accelerated early growth may reflect adaptive responses to the intrauterine environment rather than enhanced functional potential, suggesting that early culture parameters may serve as sensitive indicators of disease-related alterations.