Chances of your waters breaking at 37 weeks

At this stage, breaking waters may be a gush or a persistent trickle that you cannot control. Contact your maternity unit straight away if you think this has happened, even if contractions have not started.

The membranes form the fluid-filled sac around the baby. When they rupture, fluid may continue leaking until birth. Amniotic fluid is commonly clear or pale, and it can be difficult to distinguish a small leak from urine. A mucus plug or show is thicker and may be sticky, while waters are more watery. Contractions can start before the leak, soon afterwards, or later.

Note when the leaking began and the fluid's colour, smell and approximate amount. Put on a clean sanitary pad rather than a tampon so the maternity team can assess the fluid. Call the unit named in your birth plan and follow its instructions about assessment. Avoid sex after suspected membrane rupture because it may introduce infection. If the leak is uncertain, still call; the team can explain how it will be checked.

Call your maternity unit urgently when your waters break. Tell them immediately if the fluid is green, brown, smelly or heavily bloodstained; your baby is moving less than usual; you have vaginal bleeding, fever, severe constant pain or feel unwell. Call emergency services if you have a strong urge to push and think the baby is coming now. These warnings determine urgency, regardless of whether contractions are regular.

Ask how the team will confirm membrane rupture, check your baby's wellbeing and decide whether you can wait for labour to begin. Clarify when they want you at the unit, how to monitor movement and temperature, and which change in fluid requires another call. If labour does not start, ask when induction may be offered and what that process involves locally.