Which maternal age range is associated with an increased risk of spina bifida?

• A. Age <20 or >40 increases risk
• B. Age 25-30
• C. Age 30-35
• D. Any age

Answer: (A)

Spina bifida comes from incomplete closure of the neural tube very early in pregnancy, so maternal factors present before conception and in early gestation influence risk. The pattern with maternal age shows higher risk at the extremes: women younger than about 20 and women older than about 40 have a greater baseline risk of neural tube defects, including spina bifida, compared with those in the 20–40 age range. This rise at the ends of the age spectrum is thought to relate to factors like egg quality and folate metabolism that change with age. Across all ages, adequate folic acid before conception reduces risk, but the elevated risk in the youngest and oldest mothers explains why those age ranges are associated with increased risk.