This story of a British mother delivering her third twin after 11 years is still one of the most stunning scientific feats in history.

When Lisa was struggling to conceive a baby in 1998, she and her husband Adrian decided to use fertility treatments. As a result, doctors collected 24 eggs from Lisa with 14 of them being successfully fertilized. The mother used two of them and thus Megan and Bethany were born. The 12 remeining embryos were placed into a freezer storage.

In 2009, Lisa and Adrian decided to expand their family so they went to the same clinic and used one frozen embryo. At first, doctors warned that her body might reject the fertilized egg. Fortunately, a miracle happened and Baby Ryleigh was born, 11 years after the mother got pregnant with Megan and Bethany.

This is truly an amazing feat considering the time gap between the twin sisters and the third triplet.

Watch the video below.