Water births began happening in France and Russia over 30 years ago. Some obstetricians there began using water as an aid to help laboring women use less pain-relieving drugs, and therefore avoid some Cesarean sections. They found that warm water helped women relax so much during labor, that it sometimes sped labor up. Some women dilated so rapidly in the water that they would deliver their baby in the water because they didn't have time to get out! Some women birthed their babies in the water because they felt so good in the water that nothing would compel them to leave it.
As this happened, the caregivers noticed that the babies who were born in the water didn't try to take a breath under the water at all. The water served as an intermediate step between the womb and the world outside the womb. The babies relaxed in the water and weren't as stressed and upset as they were born.
Thus, it became popular to birth in the water, although this wasn't the original focus of using water during labor. Since then, women have birthed in the ocean, swimming pools, baby wading pools, and pools designed especially for birth.
I have had experience with water births. About 14% of my births have been water births. Most women who have a water birth wouldn't trade the experience. I don't mind including water as an option for any woman under my care, but I do encourage all moms to be flexible about their birth plan. I have seen women who had planned on having a water birth get in the water and absolutely hate it. And I've seen women who weren't planning a water birth get into the water to help them cope with their labor who just stayed in it for their birth because it felt so good.
I have purchased a birth pool! It is a Gentle Birth Pool from Waterbirth International. I plan to use it with my clients who want more depth than they have in their bathtub at home, but don't want to make a major purchase. My rental price of $100 per use is very reasonable, and I will make the birth pool available to my clients on a first-come, first-serve basis. I'm very glad to offer this to my clients, as a deep birth pool can make a real difference during labor. Please call for more information.