Meconium Aspiration Syndrome (MAS) is a respiratory complication that can affect newborns right after delivery. While not typically life-threatening, MAS occurs in 5 to 10 percent of births. Here’s what to know about this rare but serious condition.
First Things First—What Is Meconium?
Meconium, in simple terms, is what we call baby’s first poop. It’s sticky, thick, and dark green or black (almost like tar). Since your little one hasn’t actually eaten anything yet, meconium is made up of materials ingested while in the womb, like mucus, cells, bile, and amniotic fluid. Typically, your little one will have their first poop in the hours or days following birth.
What Is Meconium Aspiration?
Meconium aspiration happens when a baby has their first bowel movement before they’re born, causing them to breathe in a mixture of meconium and amniotic fluid. When baby takes their first breaths after birth, they run the risk of inhaling, or aspirating, meconium particles deep into their lungs.
What Causes Meconium Aspiration?
It’s not widely known why some babies poop before being born—and it only happens in a small number of births. For some babies it might simply be a natural, random event. For others, the early release of meconium may be caused by stress to the baby before or during delivery. Meconium aspiration is most common in babies who are full term (born at 37-41 weeks) and small for their gestational age, as well as babies born post-term (after 42 weeks of pregnancy).
What Are the Symptoms of Meconium Aspiration Syndrome?
If your baby has released meconium in the womb, the amniotic fluid will have a greenish color. This is known as meconium staining, and is one of the big reasons you should always take note of any colors or smells if your water breaks. If you notice a greenish color or foul odor in the amniotic fluid, you’ll need to inform your health-care provider immediately.
Once baby is born, signs and symptoms of meconium aspiration include:
- Yellowed skin or nails
- Rapid breathing
- Abnormal breathing sounds (such as grunting) or a coarse crackly sound heard through a stethoscope
- Bluish skin color
- An enlarged or bloated chest
- Rib muscles noticeably pulling inwards when baby breathes
Your baby’s provider will check for meconium in the amniotic fluid during baby’s birth. If they suspect any issues, they may order a chest X-ray to examine baby’s lungs, or look for meconium staining on baby’s vocal cords.
How Do You Treat Meconium Aspiration Syndrome?
If your care team knows there is meconium in the amniotic fluid, they can use a technique called amnioinfusion during labor. They’ll put a small tube through the vagina and into the uterus, and pump sterile fluid into the womb to help thin out the meconium during labor and delivery.
After birth, baby’s provider will assess the severity of the condition to determine how to treat your little one. They will look at the amount and thickness of the meconium, how long baby was likely exposed to meconium, and your little one’s ability to breathe.
Depending on baby’s condition, several treatments can help your newborn’s health improve, including:
- Suctioning out baby’s upper airways (nose, mouth throat)
- Providing oxygen via a face mask or ventilator
- Suctioning the lower airways through a tube placed in the windpipe (only used in severe cases)
In some cases, baby may develop respiratory distress or an infection, such as pneumonia. However, most babies with MAS make a noticeable improvement within a few days.
We know that conditions like Meconium Aspiration Syndrome can sound scary for mamas-to-be. But the great news is that only a small number of newborns experience this complication—and baby’s provider will be able to spot (and treat!) the symptoms of MAS immediately. You and your baby are in great hands.