Braxton Hicks contractions
Braxton Hicks contractions are named after the English doctor John Braxton Hicks who first described them in 1872. He reported many women felt contractions without being near confinement. He said this process was usually painless, but caused women confusion as to whether they were going into actual labour.
Braxton Hicks contractions are usually due to part but not all the uterus contracting. The contractions are not sufficiently strong or co-ordinated to cause cervical change. The onset of labour is defined as when there are regular co-ordinated contractions that cause the cervix to change (dilate and become thinner).
The occurrence of Braxton Hicks contractions should not be surprising as the uterus is a muscle and muscles contract. The uterus muscle has a skin on the outside called the serosa and a skin on the inside called the endometrium or decidua in pregnancy. When a woman is not pregnant contractions of the uterus muscle facilitate the release of menstrual blood and contribute to menstrual pain.