When a pregnant person says their “water broke,” they are referring to the spontaneous breaking of the amniotic sac, an event that typically signals the onset of labor. Medically, this is known as the Rupture of Membranes (ROM). This rupture releases the fluid that has surrounded the fetus throughout the pregnancy. The timing of the rupture relative to contractions is an important detail for healthcare providers planning the birth.
What is Amniotic Fluid and Why is it Important?
The fluid released when the membranes rupture is amniotic fluid, which performs several protective and developmental functions for the fetus. This fluid is contained within the amniotic sac, acting like a protective bubble inside the uterus. The composition changes over the pregnancy, starting primarily as water before becoming mostly fetal urine by the second half of gestation.
Amniotic fluid acts as a cushion, protecting the developing fetus from external pressures or impact. It also maintains a consistent temperature around the baby, creating a stable environment for growth. The fluid is actively involved in fetal development, as the baby swallows and “breathes” it to help the lungs and digestive system mature. Moving freely within the fluid allows for the proper development of the baby’s muscles and bones.
How to Know Your Water Has Broken
Identifying a ruptured membrane can be confusing because the sensation ranges from a dramatic gush to a slow trickle. The volume of fluid released depends on the location of the tear and whether the baby’s head is positioned low enough to act as a plug. Some people feel an undeniable rush of warm fluid, while others only notice a continuous, involuntary dampness.
It is common to confuse amniotic fluid with urine leakage or increased vaginal discharge, both frequent occurrences during late pregnancy. Urine typically has a distinct ammonia-like odor and a yellowish color. Its release can often be controlled, even momentarily, by clenching the pelvic muscles. Vaginal discharge is usually thicker and stickier, often resembling mucus.
Amniotic fluid, by contrast, is generally clear or a pale straw color and is usually odorless, or sometimes has a slightly sweet or musky smell. The most telling characteristic is the lack of voluntary control. If the fluid is amniotic fluid, it will continue to leak, even after the bladder has been emptied. If a pad becomes soaked with fluid that cannot be stopped, the membranes have likely ruptured, and a healthcare provider should be contacted.
Immediate Steps After Rupture
After determining the water has likely broken, the first action is to note the exact time the rupture occurred. This timestamp is important because it dictates the amount of time the fetus is exposed to the outside environment before delivery. Next, a sanitary pad—never a tampon—should be worn to absorb the fluid and allow for observation of its color and odor.
The color and odor of the fluid must be assessed immediately and communicated to the healthcare provider. Normal amniotic fluid is clear or pale straw-colored, sometimes containing white flecks of vernix (a waxy coating on the baby’s skin). If the fluid is green, brown, or has a foul odor, this signals a potential complication that requires urgent medical attention. Green or brown fluid indicates the baby may have passed meconium (their first stool), and a foul smell can be a sign of infection.
Once the membranes have ruptured, the protective barrier is gone, increasing the risk of infection. Therefore, it is important to avoid taking a bath, having sexual intercourse, or introducing anything into the vagina. Contacting the provider promptly with the time, color, and odor details is the most important step, as they will provide specific instructions on when to go to the hospital.
Variations in Rupture and Potential Concerns
The timing of the rupture determines its classification and corresponding medical management. Spontaneous Rupture of Membranes (SROM) is the term for the water breaking naturally at term (after 37 weeks). If the water breaks before labor contractions start, it is called Premature Rupture of Membranes (PROM). If this occurs before 37 weeks, it is referred to as Preterm Premature Rupture of Membranes (PPROM).
PPROM carries a greater risk of complications, mainly due to the increased time before the baby is born. The primary concern following any rupture is the risk of infection (chorioamnionitis), where bacteria can ascend into the uterus through the open cervix. The risk of infection increases the longer the time between the rupture and delivery.
A rare but serious concern following rupture is umbilical cord prolapse, which occurs when the cord slips down into the vagina before the baby. With the loss of the cushioning fluid, the cord can become compressed between the baby’s head and the pelvic opening, reducing the oxygen supply. Any sensation of something moving or slipping into the vagina after the water breaks requires immediate emergency medical attention.