Information About Artificial Rupture of Membranes (A.R.M.)
Hi, my name is Rebecca Gray, and I’m one of the Induction of Labour Coordinators at Leeds Teaching Hospitals Trust.
If your cervix is soft and open enough during a vaginal examination, your midwife or doctor may be able to feel the membrane around your baby and can break your waters. This procedure is known as an Artificial Rupture of Membranes (ARM). It is typically part of the induction process to help start labour and is generally no more uncomfortable than a standard vaginal exam.
Before the ARM procedure, we recommend monitoring your baby’s heart rate for about 20 minutes to ensure their well-being. The midwife or doctor will then perform a vaginal exam and use a small plastic instrument called an amni hook to gently break your waters. Once your waters break, fluid will continue to flow until your baby is born. There is a large amount of fluid, and new fluid is constantly being produced. You may experience occasional gushes or a slow leak, so it’s a good idea to change your sanitary pad as needed.
After your waters break, your baby’s heart rate will be monitored again, and the colour of the fluid will be checked regularly. It’s usually clear, but it can sometimes be slightly pink. In rare cases, the baby may pass meconium (poo) in the fluid, which may turn it a greenish-brown colour. If you notice a change in the colour of the fluid, inform your midwife right away.
Once your waters break and the baby’s head moves down onto the cervix, you may start to feel periodic pains. These may increase in intensity and frequency, becoming established labour contractions. With the baby’s head pressing directly on your cervix, contractions become more effective, helping to dilate the cervix and progress labour.