Emma Stacks and her husband James are just weeks away from giving birth to a little boy. They had trouble conceiving and in their first trimester, they got a scare.
"We've suffered two massive bleeds and we'd been told at one point that we had miscarried," said Emma.
Now that every is OK, Emma has a different kind of stress.
"I've had to deal with all the anxiety of being pregnant," said Emma.
Scientists at London's Imperial College say stress in mothers can cause chemical changes in the body that cross the placenta and affect the baby.
The British government is now funding a research trial to find out if hypnotherapy will increase the number of healthier deliveries.
"The birthing hormones, the oxytocin and the endorphins, all those hormones that are necessary to make labor progress, make labor happen, can work effectively," said Danielle Diosi, a natal hypnotherapy expert. "If they're scared and they're tense, then adrenalin comes into the situation and that actually stops the labor."
The courses being studied are created by a company called Natal Hypnotherapy. Couples are taught to techniques in visualization and guided relaxation. The aim is to help them overcome fears and manage their stress levels, which will help reduce the pain of childbirth.
"The more it becomes automatic behavior, so that when they go into labor, it will all be automatic, it will all kick in, and they'll be able to approach labor with a very calm, confident mind," said Diosi.
The Stacks are convinced their hypnotherapy courses have helped them know what to expect.
Natal hypnotherapy originated in the U.K. It provides workshops and CDs to expecting moms.
The British government's National Health Service is expected to complete its study in June.