Whether you’re expecting your first or fifth child, chances are you’ve got a lot of questions. After all, pregnancy is a complex and confusing time. Plus, no two pregnancies are the same.
But one question you may not have anticipated asking is, “Do babies fart in the womb?” Why? Well, to be honest, it seems silly and strange. Yet, many women search this exact phrase when they begin feeling the first flutters of movement.
So is fetal flatulence a thing?
From urination to gas to baby burps, here’s everything you need to know about how your little one digests food in the womb.
Babies don’t fart in utero. That’s because for anyone, including babies, to pass gas, they need to ingest air.
“It would seem that if babies can poop in the womb then they should be able to fart,” says Dr. Kim Langdon, a retired obstetrician and gynecologist. “But that would imply that they had some air or gas from swallowing the amniotic fluid, and there is no air to swallow.”
No air means no gas.
Additionally, flatulence occurs when you digest foods. Bacteria in the colon break down food as it digests, which leads to the release of endogenous gases. However, since babies do not digest food in utero, they cannot (and do not) produce gas.
While babies are unable to fart in the womb, they do produce urine and waste. In fact, according to the American College of Obstetricians and Gynecologists (ACOG), your baby will begin urinating sometime between 13 and 16 weeks gestation, when their kidneys are fully formed.
The good news is the urine is flushed from the womb (and your system) via the placenta. However, some urine remains in the amniotic fluid. In fact, by 20 weeks, most of the amniotic fluid is urine.
Most babies do not burp in the womb. After all, like farting, burps are created from excess gas, and since the womb lacks air pockets, burps cannot develop.
“Burping would imply there is air in the esophagus, which cannot happen because the lungs are not filled with air; they’re filled with amniotic fluid,” Dr. Langdon explains. “But the action of burping may occur if your baby ingests amniotic fluid.”
That said, hiccups can and do occur on a regular basis. They’re an involuntary spasm of the diaphragm muscle and different than breathing or swallowing air.
“Hiccups are a sign that baby is developing correctly and neurologically,” says Dr. Jennifer Taylor, an OB-GYN at Mercy in Baltimore, Maryland.
Hopefully, your baby doesn’t poop in the womb. In rare cases, it can happen. But usually, babies don’t defecate until after birth.
While babies receive nutrients from their mother via the umbilical cord and placenta, they don’t digest food — at least not in the conventional sense. As such, they don’t process waste the same way they will after birth.
“Babies don’t digest any food,” Dr. Langon explains. “Instead, they receive nutrients from the placenta, supplied by the mother’s blood. That said, babies can swallow amniotic cells and other debris, like lanugo hair, intestinal cells, mucus, bile, and the waxy coating that occurs on some babies — known as vernix. However, this is not digested and actually becomes the source of the first bowel movement [after birth], called meconium.”
Babies usually defecate shortly after birth. However, in some cases, babies pass meconium before birth, which can lead to meconium aspiration syndrome (MAS).
While those flutters you’re feeling may seem gas-like, especially those early bubbles and pops, they aren’t gas. Rather, they’re tiny movements.
“The flutters a mom feels when pregnant, particularly between 16 and 22 weeks, is often little feet and hands,” Dr. Taylor explains. “As the pregnancy progresses, movements become stronger and more intense. However, later flutters are often caused by hiccups and/or newborn reflexes.”