Objectives: Hypertensive disorders of pregnancy can lead to significant maternal and neonatal complications. No established tests have a high predictive value for PET severity and adverse outcomes. We aimed to investigate the correlation between the aspartate aminotransferase-to-platelet ratio index (APRI) and adverse outcomes in women with PET. Study design: A population-based cohort study at a tertiary medical center was conducted. Population: The study included all women with singletons between the years 2020 and 2022, with PET diagnosis. Women with incomplete records, multiple gestations, and known fetal malformations were excluded. Methods and setting: The median APRI index was used as a cut-off point, allowing us to compare the risk of complications between those with a low and high APRI index. Main outcome measures: Obstetrical and neonatal complications in women with PET in both groups were studied. Results: The study included 513 women with PET who met inclusion criteria. The median APRI index value was used as a cut-off, resulting in 255 women with an APRI index <0.26 and 258 women with an APRI index > 0.26. A higher APRI index was found to be significantly correlated with having a small for gestational age (SGA) newborn and preterm delivery before 34 weeks after controlling for parity, previous cesarean delivery (CD) and maternal age (adjusted OR 1.60, 95% CI 1.01-2.55; p=0.047 and adjusted HR 1.75, 95%CI 1.12-3.09, p=0.047, respectively). Conclusion: In patients with PET, an APRI index > 0.26 is associated with an increased risk for SGA and preterm deliveries. Funding: This study was not funded.