The Outer Limits (1995) : 4x8

The birth of a child is a joyful event, but for Shal and Brav, two young naive humans who live in a small commune in the woods, it is also a mystery and moment tinged with sadness. After Shal gives birth to a son, the first of the commune to do so, she and the baby are taken away by Mother, a wise alien who acts as a parent to the young people. When the aliens send Shal home without her baby, she asks Brav to help her to rescue the child. With the knowledge Shal has gained from her time with Mother, they break through the protective barrier set up by the aliens to discover a new and fascinating world. It is a dangerous trip, with stinging, snake-like crawlers lurking in the shadows. But, it is also a journey of discovery as Shal and Brav find evidence that lead them to believe that their real parents were killed by the aliens. They find their baby, and after a fight with an alien, escape into the forest.