Childbirth, ranking high among the most painful and physically intense experiences a person could ever endure, apparently could also be among the most blissful, pleasurable, and orgasmic.

French psychologist, Thierry Postel, conducted a survey on 956 midwives, asking them about their experiences with birthing women and if they had ever seen a woman experience orgasm while giving birth — also called ecstatic births, according to Counsel&Heal.

In total, the midwives delivered 206,000 babies, and reported 668 cases in which they were told by the mothers that they experienced orgasmic sensations during birth. An additional 868 cases were reported during which the midwives witnessed the mothers experiencing signs of ecstasy during the process of giving birth.

"When a baby's coming down the birth canal, remember, it's going through the exact same positions as something going, the penis going into the vagina, to cause an orgasm," Dr. Christiane Northrup, a board- certified OB-GYN, told ABC News in 2008. "And labor itself is associated with a huge hormonal change in the body, way more prolactin, way more ocytocin, way more beta-endorphins — these are the molecules of ecstasy."

Postel chose midwives for his survey because he felt that they had a more personal connection than doctors or nurses of the pregnant women. He also believes that the 0.3 percent of women that reported ecstatic births is low and not representative of the true number, which he says might be because women were too shy to admit reaching orgasm.

Ecstatic births were also featured in the documentary Orgasmic Birth: The Best-Kept Secret, by Debra Pascali-Bonaro, a childbirth educator.

"It is, as we say, the best-kept secret," she told ABC News. "I believe by women having such terrible fear. ... Women aren't getting the choices they need to make the experience as easy as possible."

Northrup supports Pascali-Bonaro's claim too.

"Whenever you expect pain, you tense up your muscles, your stress hormone levels go up and that increases pain," she said.

However, for some women, thresholds between pain and pleasure could be different. Barry Komisaruk, a psychology professor at Rutgers University said that the stimulation of the vaginal canal could be pleasurable for some women, but not for others.

"There are so many factors that could make the difference between a pleasurable response and a terribly stressful, aversive experience that you can't generalize it," he told Counsel&Heal. "There's no reason to try to generalize. Different people have different pain thresholds. Different people have different attitude. If a woman has a fear of sexuality, if she starts having a pleasurable sensation she may feel this is completely inappropriate psychologically, and that itself would be an aversive effect."

See the ABC News interview below, featuring Pascali-Bonaro, Northrup, as well as mothers narrating their own experiences.

Source: Postel T. Childbirth Climax: The Revealing of Obstetrical Orgasm. Sexologies. May 2013.