What is High Rupture of Membranes? The Dangers of Leaving It Unnoticed【Supervised by doctor】

Introduction

As the due date approaches, many pregnant women may feel anxious about when their water will break or labor will begin. This is especially true for first-time pregnancies and deliveries. Once pregnancy is confirmed, it is important to learn about the progression from early pregnancy to childbirth and to prepare in advance so that you are not caught off guard by sudden rupture of membranes.

What is Rupture of Membranes?

Rupture of membranes refers to the breaking of the amniotic sac that surrounds the baby, causing amniotic fluid to flow out through the vagina. Typically, rupture of membranes occurs when labor contractions are at their strongest and the cervix is widening.

Complete Rupture and High Rupture

The condition where the amniotic sac ruptures due to the internal pressure of the uterus and the baby’s head pushing against it, causing amniotic fluid to gush out of the mother’s body, is called “complete rupture” or “low rupture.”

On the other hand, when the amniotic sac ruptures at a location away from the cervix and amniotic fluid leaks out, it is referred to as “high rupture of membranes.” In the case of high rupture of membranes, the amniotic fluid does not flow out in large amounts but rather trickles out in small quantities. As a result, many pregnant women might not notice high rupture of membranes or mistake it for urine leakage.

Premature, Early, and Timely Rupture of Membranes

In a typical childbirth process, the sequence involves labor contractions, full dilation of the cervix, rupture of membranes, and delivery. When the membranes rupture as the cervix fully dilates, it is referred to as timely rupture.

However, some pregnant women experience rupture of membranes before labor contractions, known as premature rupture, or before the cervix begins to dilate, known as early rupture.

If the rupture of membranes occurs before 37 weeks of pregnancy, it is called preterm premature rupture, which can lead to preterm birth. Additionally, premature rupture at any stage increases the risk of infection for both the mother and the fetus. Besides infections, it can also cause fetal position abnormalities and placental abruption.

What is High Rupture of Membranes?

High rupture of membranes refers to the rupture of the amniotic sac at a location away from the cervix, resulting in a small amount of amniotic fluid leaking out. In contrast, complete rupture involves a large amount of amniotic fluid flowing out from the cervix. Due to the small quantity of fluid leakage in high rupture of membranes, many pregnant women might mistake it for vaginal discharge or urine leakage. The immediate impact on the baby after a high rupture of membranes is minimal, and fetal movements can still be felt. However, if high rupture of membranes goes unnoticed and is left untreated, it can lead to infections.

Causes of High Rupture of Membranes

The baby inside the womb is protected by a three-layered amniotic sac, consisting of the “amnion,” “chorion,” and “decidua.” The vagina and cervical canal serve to protect the uterus from bacterial infections, but this function can be compromised by infections, leading to inflammation of the amniotic sac. This inflammation can cause uterine contractions, resulting in the rupture of membranes.

There are various causes of high rupture of membranes. It can be triggered by infections such as Candida or Chlamydia, or by exerting abdominal pressure, such as lifting heavy objects during the second trimester when the amount of amniotic fluid increases. Other causes include smoking, including passive smoking, and stimulation of the uterus from sexual intercourse during pregnancy. Since sexual intercourse during pregnancy carries the risk of infections, it is essential to use condoms. Additionally, advanced maternal age is also considered a cause of high rupture of membranes.

• Infections
• When the amniotic sac becomes weakened due to chorioamnionitis (infection of the amniotic sac)
• Lifting heavy objects, or increasing abdominal pressure from actions like coughing or sneezing
• Smoking and passive smoking
• Sexual activity
• Multiple pregnancy, such as twins
• Advanced maternal age

Probability of High Rupture of Membranes

The small amount of amniotic fluid leakage in high rupture of membranes often goes unnoticed, and some pregnant women may progress to complete rupture without realizing it. Therefore, the exact probability of high rupture of membranes is not well known. However, the probability of premature rupture of membranes, which occurs before labor, is estimated to be about 10-20%.

Characteristics of High Rupture of Membranes

As a common image of rupture of membranes, many people might imagine a sudden and intense flow of amniotic fluid occurring after labor contractions. However, a large amount of fluid leakage happens during complete rupture, while in the case of high rupture of membranes, the amount of fluid is so small that it can be mistaken for vaginal discharge or urine leakage.

Many pregnant women ask, “What does high rupture of membranes feel like?” and “How much fluid leaks out?” While there are individual differences, the amount of amniotic fluid leakage in high rupture of membranes is typically small. Generally, pregnant women who are 37 weeks or more should see their doctor immediately if they cannot distinguish between discharge or urine leakage and a possible rupture of membranes.

How to Identify High Rupture of Membranes

High rupture of membranes can often be difficult to distinguish from vaginal discharge or urine leakage. However, leaving high rupture of membranes unnoticed increases the risk of infection for both the mother and the baby, so it is important to be vigilant. In many cases, hospitalization may be required depending on the symptoms. If you notice any abnormalities, contact a medical facility immediately.

Color of Discharge

The color and amount of vaginal discharge vary among individuals. Normally, during pregnancy, the amount of discharge increases, and many pregnant women may be concerned about soiling their underwear. Use breathable material for underwear and panty liners to maintain hygiene.

In case of symptoms such as fever, or if the discharge is thick yellow or green and resembles pus, there may be an infection. Additionally, if you notice a foul odor, seek immediate medical attention from your healthcare provider.

Amount of Rupture

The amount of fluid in high rupture of membranes is considered very small. Many pregnant women describe it as “trickling out” or “slowly leaking out, making things damp.” Additionally, there are not infrequent cases where not noticing high rupture of membranes and leaving it untreated for about a week leads to infections or severe complications.

Difference from Urine Leakage

The differences between high rupture of membranes and urine leakage can be determined by color, smell, and whether the flow stops or is intermittent. Amniotic fluid is usually clear or light yellow and odorless (though it may have a slightly musty smell), and does not have the distinctive ammonia smell of urine. Additionally, unlike urination, you cannot stop the flow of amniotic fluid with your own will, which is another way to distinguish between urine leakage and high rupture of membranes.

Can It Stop After Just One Time?

High rupture of membranes refers to the condition where the amniotic sac has ruptured. Once the amniotic sac is ruptured, it cannot reseal, so although the amount may be small, the leakage of amniotic fluid does not stop. If symptoms suggestive of high rupture of membranes stop after just one occurrence, it is likely to be vaginal discharge or urine leakage. In any case, if you notice any abnormalities or feel anxious, it is important not to self-diagnose but to consult your healthcare provider.

Symptoms Likely to Occur After High Rupture of Membranes

There are individual differences and variations depending on the week of pregnancy, but it may take several days after high rupture of membranes for labor to begin. Additionally, bacteria such as E. coli and Candida present in the vagina can enter through the ruptured amniotic sac, leading to intrauterine infection.

Intrauterine infection can cause the mother to experience fever, lower abdominal pain, and purulent discharge. It can also result in fetal position abnormalities and placental abruption, which have significant impacts on the fetus.

Placental abruption significantly reduces the supply of oxygen and nutrients to the fetus. In severe cases, it can result in fetal death, and thus, early delivery may be necessary.

Conclusion

During pregnancy, high rupture of membranes can happen to anyone. Since the leakage of amniotic fluid is small, it can go unnoticed and lead to severe infections, preterm birth, or miscarriage. Additionally, the amount of amniotic fluid can be checked with an ultrasound examination, so if you notice any abnormalities, be sure to consult your healthcare provider.

Pregnant women should thoroughly understand the knowledge about high rupture of membranes and the appropriate actions to take if it occurs, aiming for a healthy delivery.

Article Editorial Supervisor

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Dr Hiroshi Oka

NIPT specialist clinic, MD

Graduated from Keio University, School of Medicine