Who is most likely to have multiples?

The following factors can increase the chances that a woman will conceive multiples:

• Fertility treatment
• Age over 30 years
• A personal or family history of fraternal (non-identical) twins
• Obesity or taller-than-average height (2, 5)
• African-American race (African-American women are more likely to have fraternal twins than caucasian women, and Asian women are the least likely to have fraternal twins) (5)