Babies are being sent to the first hydrotherapy spa in the US – based in Houston, Texas – which claims to help infants reach cognitive developmental milestones up to 50 per cent faster than their peers.

The website for the Float Baby spa, which opened earlier this year, says it's safe to schedule the first US$65 (€48, £39) visit as soon as the baby’s remaining umbilical chord is gone, typically occurring between two to six months of age. The floatation experience is intended to replicate the feeling of being suspended in amniotic fluid.

“By floating, your baby is able to thrive in an already familiar water environment,” the site reads.

The research used to demonstrate that early introduction to water leads to improved oral expression, mathematics and reasoning on preschool entrance tests five years later, comes from an August 2013 study by the Australian Griffith Institute for Educational Research. The data suggested that these 'early-floaters' are between six to twenty months ahead of those who keep their feet dry.

To keep afloat in the hydrotherapy pool, babies wear inner tube devices – developed by the spa – around their necks. They are designed to support the baby’s chin and base of the head, leaving their arms and legs to move freely in the water, which is kept at 95 to 98ºF (35 to 37ºC).

Parents watch from the side of the pool as their infants move around independently for 20 minutes. There is also an option to sign up for parent-child swim classes.

The babies then receive neonatal massages from their parents after the floating session is complete. Parents are supervised by spa owner Kristi Ison, who is certified in infant massage. Ison, who has worked in the medical device industry for more than 17 years, offers lessons in the correct stroke techniques for infant massage across a US$300 (€220, £179) three-week course.

Parents use a custom blend of organic, cold-pressed oils with vitamin E to soothe their children during this massage.