It may be obvious the membranes have ruptured if there is a sudden gush of clear, colourless, odourless fluid from the vagina (birth canal). However, sometimes it is more difficult to know. There may only be a small amount of fluid. It may be pink in colour if some blood is in it, or greenish-brown if the baby has had a bowel movement. Some women mistakenly think they are leaking urine because they are constantly a little bit wet. It is hard to tell the difference. Pregnant women who notice any changes like this should keep in mind that the membranes may have ruptured.
A woman with PROM symptoms should contact her care provider. Unless advised otherwise, she should visit the office or the hospital to confirm that her membranes have ruptured. The baby’s heart rate pattern will likely be assessed using a fetal heart rate monitor to check that the umbilical cord is not being compressed. This may happen if there is very little fluid left for the cord to float in.
To confirm that the membranes are ruptured, an experienced pregnancy and birth care provider must assess a sample of the fluid. This may require using a sterile instrument to get the fluid from the vagina. The pH of the fluid will be tested, and the sample studied under the microscope to look for the typical fern-like pattern that amniotic fluid makes when it dries. A digital exam (examination in the vagina using the fingers of a gloved hand) may increase the risk of infection to both the mother and baby. This exam should not be done until there are signs of active labour.
The mother should avoid sexual intercourse. Do not put anything, such as tampons, in the vagina. She can shower, but get advice from a care provider before taking a bath or sitting in a whirlpool tub.
If the baby’s head is not low in the pelvis, there is a risk the umbilical cord may slip through the cervix (the opening at the lower end of the uterus) and into the vagina when the membranes break. If the woman can feel the cord at the opening of her vagina, this is an emergency. Get to the hospital as soon as possible, preferably by ambulance. In the meantime, lie with the feet and buttocks up higher than the head to help keep pressure off the cord.
In the past, women who had PROM were thought to be at risk of a ‘dry birth.’ The concern was that difficulties could occur because all the fluid was gone. What actually happens is that the placenta and the baby continue to produce fluid even after the membranes are ruptured. (The baby makes fluid by peeing.) It is possible for fluid to collect again, especially if only a little leak was there to begin with and the hole seals over.
When PROM occurs at or near the due date, most women start naturally into labour soon afterwards. Difficulty can arise in trying to decide what to do when labour does not happen on its own. Should labour be induced (started artificially)? Is waiting longer for natural labour better?
Once the membranes rupture, the risk of infection is increased as the membrane barrier is no longer present. It is also possible that an infection led to the membranes rupturing in the first place. An induced labour also has risks, including contractions that are too long or too frequent for the baby to tolerate well.
Studies have shown that inducing labour or waiting up to four days for labour to begin naturally are both appropriate. If the choice is to wait, it is important to make sure both mother and baby stay healthy. The mother may be asked to come in to have the baby’s heart rate checked every 12 to 24 hours. She should make certain that her baby’s movements are staying normal. At least 10 movements should be noted in a two-hour period of close observation. She should also check that the fluid stays clear and she is not feverish or bleeding. If any of these problems occur, she should go to the hospital immediately.
As there is risk of infection when membranes are ruptured for a prolonged period of time, the woman may be given antibiotics during labour. After birth, the baby may be observed and, if necessary, treated for infection.
Water may break early, several weeks before the expected delivery date. This is known as preterm PROM or PPROM. If there is no sign of infection, such as fever, tenderness of the uterus or odour to the fluid from the vagina, waiting is usually recommended. Antibiotics may be given to reduce the chance of infection. If birth takes place very early, at less than 32 to 34 weeks of pregnancy, steroid medication will be given to help the baby’s lungs work better. Some pregnancies will be monitored by frequent ultrasound to monitor the health of baby and see if the fluid re-accumulates.
Although you may worry that your water might break in a public place, most of the time it either occurs with active labour or the leaking is so slight that no one else is aware it has happened. If you suspect that your membranes have ruptured before labour begins, see your doctor to confirm this is what has happened. At this point, you and your care provider can discuss the best way to manage the next steps.
The rupture of membranes is exciting as it often signals the beginning of one of life’s most important adventures, the birth of a child.