During most of the pregnancy, the tiny opening in the cervix is plugged with mucus. In the last few days of pregnancy, the cervix may begin to open. Sometimes the mucus and a little bit of blood drip out of the vagina. This is called show. It may come out all at once, like a plug, or it may leak slowly for several days. When you see the show, you know that the cervix is softening, thinning and beginning to efface (open). Be careful not to confuse the show with the normal discharge (wetness from the vagina) that many women have in the two weeks before labour begins. That discharge is mostly clear mucus and is not coloured a little bit red with blood.

True labour may be spontaneously established with or without show and with or without leakage of amniotic fluid (the waters in the fetal membranes surrounding the baby). In many places, people think that labour is not progressing if they don't see leakage of amniotic fluid either before or after labour begins. This is not true. You should be clear that show and leakage of amniotic fluid are not required for labour to begin or progress.

When the bag of waters breaks (fetal membranes rupture), there can be a big gush of amniotic fluid from the vagina, or a slow leak. In most women, the bag of waters normally breaks during early labour. If the fetal membranes rupture before labour begins, there should only be a few hours delay before labour starts. If labour does not start within 6 hours after the bag of waters breaks, there is a risk of infection entering the uterus, which gets stronger the more time that goes by after the membranes rupture. Remember that 'premature' refers to the fetal membranes rupturing 'early' (before labour starts) – not to the gestational age of the baby, which may be preterm, term or post-term when the waters break.

However, even if the fetal membranes break after labour begins, as is normally the case, there are some risks associated with the leakage of amniotic fluid that you should be aware of.