Leaking amniotic fluid is mostly clear and odorless but may contain blood or mucus. It is usually a sign of labor. It can sometimes rupture early, which is called premature rupture of membranes (PROM).

Amniotic fluid is the liquid that surrounds a fetus in the womb. It has a range of functions, all of which relate to the development of the fetus.

The fetus and fluid stay in the amniotic sac, which usually breaks when a person goes into labor. Some people refer to this as “water breaking.” However, amniotic fluid may leak due to other reasons.

In this article, learn about the signs that amniotic fluid is leaking, the common causes of PROM, and when to contact a doctor.

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Leaking amniotic fluid might feel like a gush of warm fluid or a slow trickle from the vagina. It will usually be clear and odorless but may sometimes contain traces of blood or mucus.

If the liquid is amniotic fluid, it is unlikely to stop leaking.

Vs. urine

The uterus sits on the bladder during pregnancy, so it is not uncommon for pregnant people to leak urine. If the discharge smells like urine, it probably is.

Vs. discharge

Amniotic fluid differs from discharge. Discharge tends to have a mild smell and look milky.

The amount of discharge may increase toward the end of the pregnancy. A person may also notice streaky or sticky pink mucus in the discharge around the last week of pregnancy. This is because the mucus in the cervix begins to come away.

Learn more about vaginal discharge during pregnancy.

The amniotic sac ruptures when a person goes into labor. People often refer to this as the water breaking.

Sometimes, the amniotic sac breaks or leaks before labor starts. If the amniotic sac breaks before the 37th week of pregnancy, doctors refer to it as preterm PROM (PPROM).

According to a 2023 article, factors that can increase the likelihood of PPROM include:

  • having a history of PPROM
  • vaginal bleeding during the second or third trimester
  • having a short cervix
  • uterine overdistention, which refers to a larger uterus
  • copper deficiency
  • ascorbic acid deficiency
  • connective tissue disorders
  • low BMI
  • low socioeconomic status, which may make it harder to receive proper prenatal care
  • smoking cigarettes
  • illegal drug use

In some cases, there is no identifiable cause for PPROM.

If the fluid does not appear to be urine or discharge, it is best to speak to a doctor.

People who experience the following symptoms should also seek medical attention:

  • foul-smelling, brown, or green discharge from the vagina
  • fever
  • the uterus feeling tender
  • rapid heart rate
  • a decrease or lack of increase in weight

While waiting for medical attention, the individual should not use tampons, have sex, or do anything else that might introduce bacteria into the vagina.

A doctor may take a sample of the fluid to determine whether it is amniotic fluid. They may also carry out tests to determine the cause of the leak.

These tests could include a vaginal exam to see if the cervix is dilating and the individual is in labor. An ultrasound can help doctors check how much fluid is surrounding the baby.

They may also perform a dye test, which involves introducing blue dye into the amniotic sac and asking the individual to wear a sanitary pad. If the dye shows up on the pad, this can indicate leaking amniotic fluid.

Treatment will depend on the cause of the amniotic fluid leak, as well as the age, health, and development of the fetus.

A doctor may recommend bed rest, meaning that the individual should reduce her activities and rest for most of the day. They may also advise abstaining from sex.

If the individual has an infection, a doctor will prescribe antibiotics that are safe to take during pregnancy.

If the baby is ready to be born, doctors may choose to initiate labor using a drug called oxytocin. Alternatively, medications called tocolytics can help stop premature labor if it is too early for the birth to occur.

Learn more about when and how doctors might induce labor.

Leaking amniotic fluid will usually be clear and odorless and will continue to leak. Some people refer to it as water breaking, and it is often a sign that a person is going into labor.

Early rupture is known as premature rupture of membranes (PROM). If the amniotic sac breaks before week 37 of the pregnancy, it is called preterm PROM (PPROM).

Treatments for leaking amniotic fluid can vary. A doctor can advise on whether it is best to initiate or stop labor. They may also prescribe medications.

A person should contact a doctor if they believe the amniotic fluid is leaking. The doctor may order tests to confirm the presence of amntiotic fluid, and advise on the next steps a person may need to take.