The most important risk factor for developing preeclampsia is:

• A. Nulliparity
• B. Socioeconomic status
• C. Young maternal age
• D. BMI extremes

Answer: (A)

Nulliparity is the strongest independent risk factor for developing preeclampsia because the first pregnancy is when placental invasion and remodeling of the uterine arteries are most variable and less established. This placental maladaptation lays the groundwork for later maternal hypertension and proteinuria. Other factors like extreme BMI, young maternal age, or lower socioeconomic status can increase risk, but their contribution is generally smaller when considered alone, and they often interact with other risks. In practice, a first pregnancy warrants close monitoring for preeclampsia due to this higher baseline risk.