Maternal Plasma Placental Growth Factor (PlGF) Change Patterns and Adverse Perinatal Outcomes: A Retrospective Cohort Study.

OBJECTIVE: To identify distinct longitudinal change patterns of maternal placental growth factor (PlGF) across pregnancy and evaluate their independent associations with adverse perinatal outcomes. METHODS: In this retrospective cohort study, 229 women with singleton pregnancies complicated by preeclampsia and complete PlGF measurements in early (11+0 to 13+6 weeks), mid- (20+0 to 24+6 weeks), and late (28+0 to 34+6 weeks) pregnancy were included. Latent class mixed models (LCMM) were used to identify distinct non-linear trajectories of PlGF. Model selection was based on Bayesian Information Criterion (BIC). Stepwise multivariable logistic regression models were applied to assess associations between PlGF trajectory groups and adverse outcomes, including small-for-gestational-age (SGA), preterm delivery, and neonatal intensive care unit (NICU) admission. RESULTS: Three distinct PlGF trajectories were identified: (1) standard escalating trajectory (79.5%), (2) chronic low-slope growth (15.3%), and (3) late-term precipitous decline (5.2%). Absolute event counts were 15/182, 11/35, and 4/12 for Small-for-gestational-age (SGA). 25/182, 5/35, and 9/12 for preterm delivery. 19/182, 5/35, and 8/12 for NICU admission in the standard escalating, chronic low-slope, and late-term decline groups, respectively. Compared with the standard trajectory, both abnormal patterns were significantly associated with increased odds of SGA, with adjusted odds ratios (aOR) of 6.54 (95% CI: 2.49-17.41) for chronic low-slope growth and 9.25 (95% CI: 2.03-40.13) for late-term decline. Late-term precipitous decline was strongly associated with preterm delivery (aOR: 32.37, 95% CI: 7.79-180.58) and NICU admission (aOR: 23.86, 95% CI: 6.09-112.02). Chronic low-slope growth was not significantly associated with preterm delivery or NICU admission. CONCLUSIONS: Distinct longitudinal patterns of maternal PlGF provide important prognostic information beyond single time-point measurements. In particular, a late-term precipitous decline in PlGF identifies pregnancies at markedly elevated risk for preterm birth and neonatal morbidity.