Contractions are when the muscles of your uterus tighten and relax to get ready for childbirth. These muscles help push your baby down the birth canal. Once you reach week 37 of your pregnancy, it ...
Muscle contraction is the tightening, shortening, or lengthening of muscles when you do some activity. It can happen when you hold or pick up something, or when you stretch or exercise with weights.
PregaTips on MSN

When contractions go wrong

Labour contractions are your body’s way of guiding your baby into the world. But when they become too intense, too frequent, or too weak to make progress, labour can go off rhythm. Hypertonic labour ...
A gush of water, being doubled over in pain, the head of your baby crowning. These are things many women picture when they think of labor. However, for most laboring women, these things take time and ...