What Is Amnioinfusion?

If you’re experiencing a high-risk pregnancy — especially if you’ve been told your amniotic fluid levels are low — you may have heard of amnioinfusion. But what is amnioinfusion, and how can doctors use this treatment to care for pregnant women and their babies? 

The term amnioinfusion can sound pretty intimidating — clinical, even — but when you break it down, it’s a little easier to understand. Amnio refers to the amniotic fluid that surrounds your unborn baby. It’s critical for your baby’s growth, protection and development. Infusion refers to how a synthetic version of that fluid is delivered in the rare case that you don’t have enough of your own. 

Amnioinfusion is the process of adding more fluid to your uterus via a needle, catheter or port. 

Here’s how Dr. Kevin Magee, maternal-fetal medicine specialist and founding partner of Fetal Care Center Dallas, puts it: “An amnioinfusion is a procedure that attempts to provide the unborn child with enough fluid during the critical window for lung development.” 

The definition of amnioinfusion is pretty straightforward, but of course, you have more questions — especially if your doctor has recommended the treatment. In this post, we’ll cover what you need to know about amnioinfusion and what conditions it can treat.

What Is Amnioinfusion? 

As we said above, amnioinfusion is a procedure where fluid — in the form of saline or Ringer’s solution (the amnio part) — is added to the womb before birth (the infusion part). Let’s focus on the infusion part. There are several ways this can happen. You and your doctor will determine the best course for your pregnancy. 

• During transcervical amnioinfusion, a doctor will place an intrauterine pressure catheter (IUPC) into a partially dilated (1 to 2 cm) uterus. Then, fluid is pumped via IUPC into the uterus. 
• In transabdominal amnioinfusion, a doctor will use ultrasound to guide a small needle inserted through your abdomen and into the uterus and amniotic sac. 
• In some cases that require longer-term amnioinfusions, fluid can be delivered via a subcutaneous amnioport to maintain amniotic fluid volume.

If your doctor recommends amnioinfusion, the procedure will take place in the hospital under the guidance of your care team. You may experience mild cramping or discomfort. Your health care team will monitor you and your baby throughout the procedure.

Why Amnioinfusion? 

About 12 days after you get pregnant, a membrane forms in your uterus around your growing fetus. This is called the amniotic sac. From then on, your baby will grow and develop inside the amniotic sac, surrounded by amniotic fluid. In a typical pregnancy, the sac ruptures and induces labor. That’s what is happening when your “water breaks.” 

In the beginning, the fluid is mostly made up of water. According to the March of Dimes, after about 20 weeks, “your baby’s urine makes up most of the fluid. Amniotic fluid also contains nutrients, hormones (chemicals made by the body) and antibodies (cells in the body that fight off infection).” 

As your baby grows, the amniotic fluid provides a cushion that protects the fetus. But it does more than that. Amniotic fluid:

• Keeps the temperature inside the uterus stable, which is essential for proper fetal development 
• Allows the fetus to move freely, which helps develop the musculoskeletal system
• Helps in lung development by allowing the fetus to practice breathing movements 
• Assists in the development of the gastrointestinal tract 
• Keeps the umbilical cord from getting compressed, which can lead to decreased blood flow to the fetus

The amount of amniotic fluid can change during pregnancy, and sometimes, there may not be enough amniotic fluid surrounding your baby. This condition is known as oligohydramnios.

Oligohydramnios: What Is it and Why Does it Happen? 

Oligohydramnios is the medical term for when a pregnant person has too little amniotic fluid. There are a number of reasons why you may have too little fluid, including: 

• If your water breaks too early (PROM)
• Your placenta peels away from the wall of the uterus (placental abruption)
• Health conditions, such as chronic high blood pressure or diabetes
• Use of some medications, such as angiotensin-converting enzyme (ACE) inhibitors
• Certain health conditions in the baby, such as renal failure or genetic disorder

Oligohydramnios can happen any time during pregnancy, but it’s most common in the last three months (last trimester). According to the March of Dimes, about 4% of pregnant women experience oligohydramnios. Your provider can detect low fluid levels via ultrasound. If you think you’re leaking amniotic fluid, call your provider right away. Low fluid levels can be dangerous for your baby. 

If you experience oligohydramnios in the first six months (first or second trimesters) of pregnancy, you’re more likely to see serious complications, including: 

• Congenital disabilities
• Miscarriage
• Premature birth
• Stillbirth 

Later in the pregnancy, oligohydramnios can cause slow growth, problems during labor and increase your chances of needing a cesarean section. 

What Conditions Does Amnioinfusion Treat? 

Amnioinfusion is not a new treatment; it’s been used to treat oligohydramnios since the 1980s. But as technology and medicine advance, amnioinfusion is becoming an increasingly viable option throughout a pregnancy. Two such cases are in treating preterm premature rupture of membranes (PPROM), and fetal renal (kidney) failure or abnormalities. 

Amnioinfusion and PPROM

When a woman’s water breaks early, it is called premature rupture of membranes (PROM). This usually triggers labor within 24 hours. If the water breaks before 37 weeks gestation, it’s called preterm premature rupture of membranes (PPROM). The earlier your water breaks, the more serious it can be for your baby. 

A 2014 literature review found promising results using transcervical amnioinfusion in women with PPROM. And in another study, two women received amnioinfusion via subcutaneous port — one in the 23rd, the other in the 21st week of gestation — with exciting outcomes for both. 

“The newborns showed no signs of lung hypoplasia and were successfully extubated on the first or second day after delivery,” the study reads. “Six months later, the children did not exhibit any deviation from the normal development.”

Amnioinfusion and Kidney Problems

As medical technology continues to evolve, so do the methods and techniques used in amnioinfusion. A 2020 Mayo Clinic study explored serial amnioinfusion therapy in cases where the fetus had kidney and urinary tract problems. 

Kidney failure in the womb can lead to low fluid levels, which in turn means their lungs won’t have enough fluid to develop properly. If left untreated, says Dr. Magee, “children with fetal renal failure have a high fatality rate.”

Authors of the Mayo Clinic study noted there still isn’t sufficient evidence to recommend routine use of amnioinfusion in PPROM or renal failure cases, but the research is promising.

Support and Care During Amnioinfusion: Why it Matters

If you’re experiencing a high-risk pregnancy, it’s important to remember that you are not alone. Whether you are undergoing amnioinfusion or any other treatment, the support and care of those around you can make a big difference.

Start with your health care team. They are there to provide expert care and guidance and to answer any questions you may have. Communicate openly and honestly with your team and let them know if you have any concerns or questions.

Outside the clinic or hospital, family and friends are an invaluable source of support, comfort and reassurance. From emotional support to help with practical tasks, let them be there for you during this stressful and challenging time.