The amniotic sac plays an important role in keeping a fetus healthy during pregnancy. In this article, we’ll define the term “amniotic sac” and explain how it relates to birth injury law.

Key Takeaways

• The amniotic sac is a thin sac surrounding a fetus during pregnancy
• The amniotic sac is made of two membranes - the amnion and chorion - and filled with amniotic fluid
• The term “water breaking” refers to a rupture of the amniotic sac
• Functions of the amniotic sac include cushioning the fetus, maintaining a steady temperature, and helping the fetus properly develop
• Premature rupture of the amniotic sac happens in 8-10% of pregnancies

What Is the Amniotic Sac?

The amniotic sac is a thin sac that surrounds a fetus during pregnancy. It is filled with a liquid called amniotic fluid. The membrane covering the fetal side of the placenta is called the amnion and the outer layer is called the chorion. The amniotic sac forms approximately 12 days after the beginning of the pregnancy and is fully formed within the first three weeks. 

The amniotic sac has several functions including regulating the fetus’ temperature and protecting it from injury. 

The amniotic sac typically remains intact throughout the pregnancy until the amniotic membranes spontaneously rupture, releasing the amniotic fluid. This happens immediately before spontaneous labor (and sometimes after), and is what is colloquially referred to as the “water breaking.” 

In the early weeks of pregnancy, amniotic fluid is mostly water coming from the pregnant person’s body. After about 20 weeks, the fetus’ urine makes up most of the amniotic fluid. The amount of amniotic fluid increases until about 36 weeks of pregnancy, at which point it usually begins to decrease. Too much or too little amniotic fluid can both be problematic.

Functions of the Amniotic Sac

Functions of the amniotic sac and the fluid inside of it include:

• Helping the fetus’ muscles and bones develop
• Cushioning and protecting the fetus
• Keeping a steady temperature around the fetus
• Helping the fetus’ lungs grow and develop
• Helping the fetus’ digestive system develop
• Keeping the umbilical cord from being squeezed

Premature Rupture of the Amniotic Sac

When the amniotic sac ruptures before 37 weeks of pregnancy, it is called preterm premature rupture of membranes (PPROM). It occurs in about 8 to 10% of all pregnancies accounting for one-fourth to one-third of all preterm births. 

Premature rupture of the amniotic sac can be caused by a variety of things including:

• A natural weakening of the membranes
• The force of contractions
• Infection in the uterus
• A lack of proper prenatal care
• Sexually transmitted infections (STIs) like chlamydia and gonorrhea
• Previous preterm birth
• Vaginal bleeding
• Cigarette smoking during pregnancy
• Unknown causes

The Amniotic Sac and Birth Injury Law

Sometimes, when healthcare professionals fail to meet the standard of care, it can lead to issues with the amniotic sac that can cause complications and birth injury. For example, sometimes doctors use an amniotic hook to artificially rupture the amniotic sac. However, this can injure the baby, causing lacerations. 

When these types of issues are caused by negligence on the part of your healthcare team, they are considered medical malpractice. If you or a loved one have experienced amniotic sac issues because of medical negligence, it is recommended that you speak to an experienced birth injury lawyer to help you recover compensation for your pain and suffering.