Six important facts about water breaking

For some mothers, the water really gushes out during childbirth, whereas others experience trickling even weeks before the due date. After certain pregnancy weeks, water breaking prematurely is no disaster but it’s worth keeping an eye on. Doctor Vedran Stefanovic, perinatologist at HUS’ Women’s Hospital, answers some important questions about premature water breaking.

1. What is amniotic fluid and what is it needed for?

Amniotic fluid protects the fetus from external threats, helps it move in the womb and develops the baby’s lungs and digestive system. It’s a liquid that contains important nutrients and other substances that protect the fetus, such as proteins, lipids and amino acids.

“Amniotic fluid allows the fetus to grow safely in the mother’s womb”, Vedran Stefanovic explains.

Amniotic fluid allows the baby to move its arms and legs in the womb, which means that the baby’s muscles and bones develop. The fluid also protects the baby from bacteria and infections, as well as sudden blows and movements.

Amniotic fluid is formed in the mother’s womb during the first trimester and its amount increases during the entire pregnancy. In the early pregnancy period there is only a few millilitres of fluid, but later on there is up to a litre or one and a half litres of fluid. The amount of amniotic fluid decreases towards the end of pregnancy as the baby swallows it.

2. What does premature water breaking mean?

Preterm premature rupture of membranes is usually followed by premature birth.

The fetal membranes make up the amniotic sac, which keeps the amniotic fluid safely inside the womb. Normally, the membranes rupture and the water breaks during labour, or a few hours to a day before going into labour. If the water breaks before the 37th week of pregnancy, it is called preterm premature rupture of membranes (PPROM ).

“The amniotic sac is like a balloon. When a balloon breaks it empties. If the amniotic sac ruptures, the amniotic fluid will either leak out slowly or gush out”, Stefanovic says.

Preterm premature rupture of membranes is usually followed by premature birth. The decision over whether the mother will give birth early or will the baby be kept in the womb after PPROM is made on a case-by-case basis.

“You can’t accidentally cause preterm premature rupture of membranes yourself. You also can’t prevent or hold back water breaking in any way”, Stefanovic says. “Most mothers with PROM give birth within a week.”

With no amniotic fluid in the womb there is a risk of infection. The later in pregnancy the water breaks, the smaller the risk of losing the baby. The fetus is more mature in later weeks, which means that labour can be started.

3. What causes PPROM?

PPROM and premature birth resulting from it is not very common. In Finland, about 5–6 percent of all newborn babies are born premature, and only around one percent are born before the 32nd week of pregnancy.

“The most common cause of PPROM is a latent intrauterine infection, which triggers premature birth”, Vedran Stefanovic says.

A second cause of PPROM is too much amniotic fluid in the womb, whereupon the womb cannot keep the fluid inside. Too much fluid may be caused by the mother having diabetes, or a fetal structural disorder where the baby cannot swallow the fluid.

A third cause of PPROM is multiple pregnancy. In this case, there is a normal amount of amniotic fluid, but the fetuses take up more space. The human womb is normally meant for one fetus at a time in pregnancy. PPROM is more common in multiple pregnancy, because the womb may contract prematurely.

A rare cause of PPROM is when amniocentesis, also called an amniotic fluid test, is done to the mother. If amniocentesis is done, it’s usually done between the 15th and 22nd week of pregnancy. Amniocentesis is performed by taking a sample of the amniotic fluid with a needle, from which the fetal cells’ chromosomes are examined. The sample helps doctors evaluate the fetus’ health status and possible abnormalities, such as Down syndrome. The probability of PPROM caused by amniocentesis is still very low.

4. How do you know if your water has broken?

Your water can break without any contractions. Sometimes the fluid gushes out and sometimes it trickles out slowly. In the latter case, it may be hard to determine whether it’s a different kind of vaginal discharge. If you suspect that your water has broken, put a pad in your underwear and monitor the situation.

“It’s better to contact the hospital from the slightest suspicion or too early than not at all”, Stefanovic says.

During pregnancy, ordinary white vaginal discharge can be very runny and watery, but sticky. The liquid is amniotic fluid if it’s a watery liquid that really flows out and your pants get wet.

The doctor will conduct the necessary examinations at the hospital, so the mother doesn’t have to accurately identify the leakage. If you suspect that your water has broken, contact the maternity hospital’s emergency clinic. The issue can be confirmed with an Actim PROM dipstick test done at the hospital.

5. When is water breaking a risk?

The later the water breaks, the safer the situation is for the baby. If the water breaks in the second trimester and pregnancy ends before the 22nd week, it is referred to as a miscarriage, or pregnancy loss. From the 23rd and 24th week of pregnancy onwards, it is possible to save the baby.

“Fetal age is a more important factor than fetal weight. During each week of pregnancy, the fetus develops more crucial vital functions”, Stefanovic says.

After the 37th week of pregnancy, water breaking is a normal occurence of pregnancy and there are few risks involved.

“You don’t have to worry about the fetus having an acute emergency in the last trimester. The fetus gets oxygen and food even if the water has broken. There is just the risk of the uterus becoming infected afterwards. That’s why it’s always necessary to contact the hospital if you even suspect that your water is trickling out.”

6. When should you contact the hospital?

“It’s important that you call the hospital and ask for further advice whenever you’re in any doubt. You should be especially careful if you are at risk of PPROM. For example, if the maternity clinic has discovered that there is too much amniotic fluid, if it is a multiple pregnancy or if you have had an amniotic fluid test”, Stefanovic says.

“Giving birth at home right after the water breaks is extremely rare. Water breaking doesn’t mean that childbirth begins right away.”

Premature rupture of membranes can be determined at the hospital with the Actim PROM stick test