Do Babies Produce Waste Products Inside the Womb?

By Erica Loop
Your baby is eliminating the nutrients you provide through the umbilical cord.

Your baby has 40 weeks to go from a few cells to a complex human being. Even though you won’t need to hit the diaper aisle just yet, your baby is producing waste in the womb. From his developing intestinal tract to budding kidney function, your baby’s body is beginning to work out the waste well before he is born.

Digestive Tract and the Umbilical Cord

It’s month two of pregnancy, and your baby’s digestive tract is beginning to form, according to the Cleveland Clinic website. This doesn’t mean your baby is ready to eliminate waste from her body just yet. At this point, the basic organs such as her stomach and intestines are starting to develop. At week seven, your baby’s intestines are still growing but are beginning to come out of her belly and form into an umbilical cord loop. The umbilical cord allows nutrients and oxygen to pass from your placenta into your baby’s system. It also eliminates waste products and carbon dioxide from your baby’s blood.

Kidneys, Urine and Amniotic Fluid

At 12 weeks, your baby’s kidneys are ready to make urine. By 14 weeks, he’s not only making urine from the amniotic fluid he drinks, but he is also releasing it into the surrounding amniotic fluid, according to the website Baby Center. Up to this point, your body is making all of the amniotic fluid. The more your baby urinates, the more he contributes to the overall fluid amount. In utero, your baby swallows the urine that he releases into the amniotic fluid. While this may seem entirely unpleasant, it is actually helping him to practice using his developing digestive system.

Meconium Production

While in utero, your baby isn’t releasing solid waste into the amniotic fluid. At 16 weeks, meconium is beginning to build in her intestines. Meconium is your baby’s first feces. It’s thick and sticky, and usually comes out of the intestine after birth. This is your baby's first bowel movement. The meconium bowel movements may continue for a few days after birth.

Waste in the Womb

If your baby releases the meconium waste while he’s still inside of you, there’s a chance that he can aspirate – or choke – on it. Between 6 and 25 percent of newborns have meconium in their amniotic fluid at birth, according to the website KidsHealth. Not every baby with meconium in the amniotic fluid will swallow or choke on it. Fetal stress due to infections, decreased oxygen, umbilical cord complications or a difficult delivery may increase the possibility of aspirating meconium. This is an emergency situation in which the doctor needs to clear the baby’s airway immediately.

About the Author

Based in Pittsburgh, Erica Loop has been writing education, child development and parenting articles since 2009. Her articles have appeared in "Pittsburgh Parent Magazine" and the website PBS Parents. She has a Master of Science in applied developmental psychology from the University of Pittsburgh's School of Education.