When a baby is growing in a mommy's tummy, it is very safe and comfortable. But when it is ready to be born, it has to go through a big change to come out into the world. This change is called "obstetric transition."
During obstetric transition, a mommy's body goes through changes to help the baby come out. The opening in the mommy's body where the baby will come out gets bigger and softer. This is called "dilation." The mommy's muscles also start to push the baby down and out of her body. This is called "contractions."
These changes can take a long time, even hours or days! Doctors and nurses help mommy during this time to make sure she is healthy and comfy. They may give her medicine to help ease the pain or help her relax.
Finally, when the baby is ready, it will be born! This is a very exciting and happy moment for mommy and everyone else in the room. The baby will take its first breath of air and begin its new life in the world.