Measuring contractions

The spontaneous squeezing or tightening of the womb is an important part of birth, writes Sr Burgie Ireland

CONTRACTIONS CAN begin as early as six months into a pregnancy. These early contractions are called Braxton Hicks, or practise contractions. Early labour contractions begin when progesterone levels suddenly drop. These contractions are mild and far apart. In established labour, contractions become stronger, painful and are closer together. Just before giving birth, contractions are described as expulsive. Finally, after the birth the womb stays contracted to prevent haemorrhaging.

WHAT DOES A CONTRACTION FEEL LIKE?

To contract means to make smaller. This means that the womb literally gets smaller with every contraction. It also changes in shape and becomes smaller at the top and wider at the bottom, where the cervix is. Here the womb mouth opens (dilates) for the baby to pass through. When you touch your tummy, mild contractions will make it feel soft like your cheek; moderate contractions feel firm (like your chin); and strong contractions feel hard, like your forehead. Each contraction has three phases. At first the contraction only feels tight and as it gets stronger and more painful it heralds the increment stage. Gradually the contraction reaches its peak, which is when the contraction is really painful. Then it suddenly fades (decrement phase) and is quickly gone. There is no pain between contractions. This is when the womb relaxes and recovers in preparation for the next contraction.

HOW TO TIME CONTRACTIONS

The length of each contraction is timed in seconds, and the frequency (how often contractions come), is timed in minutes. In early labour a contraction may last between 15 to 30 seconds, and may be 10 to 20 minutes apart. Just before giving birth, contractions now last for 60 to 90 seconds and are one to two minutes apart. Don’t be neurotic about timing each and every contraction, but it may be helpful to have pen and paper with you to periodically record contractions and follow the progress of your labour.

WHY SHOULD I TIME THEM?

Timing contractions will help you decide whether to go to the hospital or not. Weak, irregular contractions that subside after a warm bath means that you can stay at home for a few hours longer (providing there are no other danger signs such as bleeding, headaches, waters broken or heart palpitations). Strong, regular contractions that get more painful and don’t go away after a warm bath, are a sign that it’s time to go to the hospital. In hospital, contractions will help your midwife or doctor keep a look out for potential problems. For example, short, frequent and painful contractions that don’t give the womb a chance to relax and don’t dilate the cervix are called hypertonic contractions. These can prolong labour and sedation or a drip could help to change this pattern. Contractions that are weak, infrequent and ineffective often occur in multiple pregnancies as well as if the mother has been sedated or if the baby is too big for the pelvis. This type of labour could also be very long with the added risk of haemorrhaging after the birth. Intervention may be necessary to prevent complications.