What Can Cause Superfetation?

Causes. Superfetation occurs when ova from two separate menstrual cycles are released, fertilized, and then implant in the uterus. Normally, once a woman is impregnated, physical and hormonal effects would make this impossible. Hormones are the first barrier in a normal pregnancy.

How do you get Superfetation?

Superfetation occurs when a second egg is fertilized by sperm and implants in the uterus after another fertilized egg has already done so. It's nearly impossible, though, because when someone gets pregnant, their bodies release hormones to prevent ovulation, or the release of another egg.

How often is Superfetation?

Though rare, this condition is believed to affect as many as 0.3% of women but often one twin is lost so the true numbers are not known.