Can Babies Poop in Womb?: Meconium Aspiration Syndrome

What happens if babies poop while in the womb? Learn about meconium aspiration syndrome and the health effecs on mother and baby.

Pregnant woman and child in the womb. Belly section and fetal growth

Deborah Cruz

Updated: December 1, 2022

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Does your baby poop in the womb? Well, sort of but not really. Obviously, while your baby is growing and gestating in your womb they’ll take in nutrients and they’ll need to expel that waste. However, your baby is not pooping in your womb. Babies typically “poop” for the first time after birth and that waste is called meconium.

Meconium is not like any regular poop you’ve seen before so it may be jarring for some first-time parents. It is thick, dark green in color, sticky feces made up of cells, fats, proteins and intestinal secretions of the baby. It is true that some babies can pass meconium late in pregnancy near their due date. If the meconium gets into the lungs of the baby, it can cause breathing problems for the newborn. This is called Meconium Aspiration Syndrome (MAS).

According to John Hopkins Medicine, Meconium aspiration syndrome occurs when a newborn breathes a mixture of meconium and amniotic fluid into their lungs around the time of delivery often causing fetal distress. Meconium aspiration syndrome, a leading cause of severe illness and death in newborns, occurs in about 5 percent to 10 percent of births.

Meconium aspiration syndrome can be very dangerous because the meconium can irritate and even clog the newborn’s airways during those first breaths, damage the surrounding lung tissue and block surfactant which is the fatty substance that helps open the newborn’s lungs after being born causing all sorts of issues for baby.

What Causes Meconium Aspiration Syndrome?

Close-up of a pregnant woman's belly in the hospital bed with catheter in hand

MAS happens when a baby is under duress during delivery and gasps taking in amniotic fluid with meconium. However, there are some factors that may increase the likelihood of the newborn passing meconium such as:

A long and hard delivery.
The baby is past the due date.
The baby didn’t develop at the normal rate in the womb.
Mom has health problems like diabetes or high blood pressure.
Mom smoked or used drugs during the pregnancy.
Low oxygen levels or infections.

Symptoms of Meconium Aspiration

Symptoms of Meconium Aspiration can include the following:

According to one study, a low APGAR score of less than six at 1 minute is significantly associated with meconium staining of amniotic fluid.
Limpness at birth.
Breathing problems
Bluish skin color of the infant at birth.
Dark green streaking of the amniotic fluid or obvious meconium in the amniotic fluid.

How is Meconium Aspiration Syndrome Diagnosed?

Medium close-up of a young couple watching ultrasound image of future child during ultrasound scan

There are many tests that can indicate if your baby has meconium aspiration syndrome. Here are a few common signs and symptoms that may indicate meconium aspiration.

Before the baby is even born, a fetal monitor may indicate a slow heart rate which can be indicative of Meconium Aspiration Syndrom.
At the time of birth, the doctor should check for possible aspiration by examining the newborn’s vocal cords for meconium staining.
A chest X-ray may show streaky areas on the newborn baby’s lungs.
A blood gas analysis of a newborn with Meconium Aspiration Syndrome will show low blood acidity, decreased oxygen and an increased level of carbon dioxide.
More obvious signs like abnormal breath sounds like crackly or coarse sounds can be heard with a stethoscope.

Treating Babies with Meconium Aspiration Syndrome

As soon as the baby’s head has cleared the vagina, suctioning the baby’s mouth should be done.
If the baby is experiencing fetal distress, they may be placed in the NICU.
It may be necessary to tap on the chest to loosen thick secretions.
Antibiotics may be administered to clear any infection.
The baby may be placed in a warmer to maintain body temperature.
Inhaled nitric oxide to open blood vessels and improve oxygen delivery.
A breathing machine may be necessary to fully inflate a newborn’s lungs.
A process called extracorporeal membrane oxygenation in which an ECMO machine pumps blood from the body through an artificial lung, adding oxygen to the blood while removing carbon dioxide. Then, returning to the blood back to the newborn.
If there are no signs of distress during pregnancy and the baby is full-term and healthy, doctors are warned against suctioning the windpipe as it can lead to a form of pneumonia.

How to Prevent MAS

There are different precautions and methods that can be used before and during the delivery process to help reduce the risk of or prevent meconium aspiration syndrome.

Inducing labor if mom is going past her due date.
Pregnant women whose waters break and it has dark green staining in the amniotic fluid, she should seek medical attention immediately.

Prognosis of Babies with Meconium Aspiration Syndrome

Some babies have to take special care and in severe cases may have a higher risk for lung infections, rapid breathing and proneness to wheezing in the first year of life but most newborns recover completely and go on to lead perfectly healthy lives with no obvious side effects.

In rare cases, the lack of oxygen in the uterus or complications of MAS may lead to brain damage.

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For any questions regarding complications during your pregnancy or specific health concerns, you should also consult with your doctor or OB-GYN.