Last year a woman reportedly conceived while pregnant in a extremely case of superfetation.

USA (Next Media)
A California woman reportedly conceived while pregnant in a extremely case of superfetation.

During pregnancy, a woman’s body stops producing eggs but in some extremely rare cases eggs are still produced after one has been fertilized.

This is called superfetation. In reported cases, this is where a woman conceives another child while already pregnant.

Unlike a twin pregnancy, superfetation is when two fetuses grow separately inside the same woman at different rates.

In 2009, a doctor speaking to ABC in 2009 about a case of superfetation, said she could only find 10 cases of it in medical literature.