1. Age ≥40 years or \<18 years, BMI ≥30 or \<18.5, multiple pregnancy, or history of adverse pregnancy outcomes;

2. Diagnosed autoimmune diseases, chronic hypertension, diabetes mellitus, or chronic kidney disease;

3. Infection or fever during pregnancy;

4. History of smoking or alcohol abuse, recent surgery or trauma, or use of glucocorticoids or immunosuppressants;

5. Other conditions that may cause abnormal nucleosome or placental growth factor (PLGF) levels.

Cohort Study on the Levels of Placental Growth Factor and Nucleosomes in Early Pregnancy and Adverse Pregnancy Outcomes