A baby underwent surgery in the womb for spina bifida, and since being born six weeks ago, the child is healthy and developing well, according to a statement from the Great Ormond Street Hospital (GOSH) for Children in London.

Spina bifida occurs when the so-called neural tube, a hollow structure that begins forming around the third week of pregnancy, does not develop properly and essentially ends up with a hole in it, according to the Centers for Disease Control and Prevention (CDC). The neural tube later gives rise to the baby’s brain and spinal cord, so a hole in the structure can cause mild to severe nerve damage and result in physical and intellectual disabilities.