Braxton-Hicks contractions are basically practice contractions, and are the body's way of preparing for labour. Some experts believe that they help to thin and soften the cervix, which is necessary for birth.
A woman experiencing a Braxton-Hicks contraction will feel irregular and infrequent tightenings of her uterus, which will last between one and two minutes. They occur on a totally random and sporadic basis, and their unpredictability makes them different to regular contractions.
Although they start at around six weeks of pregnancy, a woman will not normally feel a Braxton-Hicks contraction until the third trimester, but it is possible to feel them sooner than this.
Additionally, while many women experience Braxton-Hicks contractions, it is not unusual for a women to bypass this experience altogether.
Braxton-Hicks can feel quite uncomfortable, although some women do say they can be painful and can feel like the real thing.
However, they differ from true labour contractions as they will often go away if a woman changes activity, such as getting up from sitting down, or going for a walk. Labour contractions cannot be halted by these types of measures.
Braxton-Hicks are a part of pregnancy and therefore not a cause for concern. However, if they are accompanied by other symptoms such as bleeding, loss of water or a slowing down in your baby's movements, you must seek immediate medical help.