Is It Normal to Throw Up Mucus When Pregnant?

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Morning sickness, aching muscles, swollen ankles—these are some of the unpleasant symptoms most of us expect during pregnancy. But sometimes pregnancy comes with some surprises, and many of us end up experiencing some unusual (and yes, kind of gross!) symptoms.

For example, while you probably know that vomiting is a common pregnancy symptom, you might not know that some people end up throwing up mucus during pregnancy. While this isn’t an incredibly common occurrence, it can happen. It’s likely related to the fact that pregnant people end up producing more mucus than non-pregnant people, and this mucus can get expelled during an episode of vomiting.

We connected with experts to help us better understand this phenomenon, including why it happens, and whether it’s ever a reason to be concerned.

Why Do Pregnant People Experience Morning Sickness?

Before we consider throwing up mucus during pregnancy, let’s unpack the reasons pregnant people tend to vomit, and how common this is.

Nausea and vomiting during pregnancy is usually referred to as morning sickness, though the name is a bit of a misnomer, because the symptoms aren’t necessarily confined to the morning hours. Nevertheless, experiencing an upset stomach, nausea, and vomiting is common in pregnancy. Research has found that nausea affects between 70-80% of pregnant people and that about 50% of pregnant folks experience vomiting.

Morning sickness symptoms are related to those pesky pregnancy hormones. “Nausea/vomiting in pregnancy is mainly caused by hormonal changes of pregnancy,” says Susan Lipinski, MD, an OB/GYN at Obstetrix of Colorado, part of Pediatrix Medical Group. Most experts blame a hormone called human chorionic gonadotropin (hCG), which is secreted in high amounts during early pregnancy, which is also when pregnant people are most likely to experience morning sickness.

Dr. Lipinski says that however unpleasant morning sickness is, it means that your hormones are doing their job. “While it is not fun to throw up, it is a sign of a successful pregnancy,” she assures. “Those with morning sickness are less likely to miscarry.” Indeed, research has found that those who experience nausea and vomiting during pregnancy have a reduced chance of miscarriage and a greater chance of positive fetal outcomes.

Besides hormones, there are a few other factors that play into whether you will experience morning sickness and how severe it may be. Genetics may be a driving factor, with studies finding those people whose mother or sibling had morning sickness are more likely to get it themselves.

People who are pregnant with multiples, or who are more prone to motion sickness may be more likely to get the most severe form of morning sickness, a condition called hyperemesis gravidarum. This condition is characterized by weight loss, dehydration, and electrolyte imbalance. It’s usually treated with anti-nausea medication and IV fluids.

Reasons You Might Spot Mucus When Throwing Up

Robyn Garcia, MD, a maternal-fetal medicine physician at UTHealth Houston, says that she often gets questions from her pregnant patients about the appearance of their vomit. “Patients ask many questions when it comes to their morning sickness (nausea and vomiting of pregnancy) as the characteristics can be quite variable,” she says. Additionally, noticing thicker than usual saliva and increased mucus is quite common during pregnancy, Dr. Garcia notes.

Dr. Lipinksy also says that many of her patients report seeing quite a bit of extra mucus during pregnancy. “I have never had a patient specifically ask about mucus in their vomit, but many report seeing mucus,” she says. “This is common.”

And why might you see mucus in your vomit? This is likely related to the fact that increased mucus production is prevalent in pregnancy, a condition often referred to as pregnancy rhinitis. A 2013 study found that 39% of pregnant people experience increased nasal congestion.

“Nasal congestion can occur due to pregnancy hormones that dry out the lining of your nose, resulting in inflammation and swelling leading to sinus drainage,” Dr. Garcia explains. This can cause symptoms like post-nasal drip, which makes it more likely for mucus to appear in your saliva.

According to Dr. Lipinksy, drainage from the sinuses and post-nasal drip is likely a reason why pregnant people may notice mucus in their vomit. “Many pregnant people have increased sinus drainage during pregnancy; while sleeping, this drainage can go down the throat and into the stomach,” she describes. “In the morning, a stomach empty of food but full of mucus could cause nausea and vomiting.”

You might be wondering if the mucus you are seeing is actually stomach bile. Dr. Lipinksy says that mucus is yellow or greenish, but that it’s usually thicker and more gelatinous than bile. “However, many people will vomit bile with morning sickness and that can also look yellow or green,” she says.

When to Contact Your Healthcare Provider

On its own, throwing up mucus likely isn’t a problem and is quite possibly the result of the increased mucus production that is common in pregnancy. However, sometimes symptoms like excessive mucus and frequent vomiting can be a problem, especially when accompanied by other concerning symptoms.

At times, throwing up mucus can be a sign of illness. “Mucus itself is not concerning, but if a pregnant patient also has fevers, sinus pain, or other signs of a sinus infection, then they should seek treatment,” advises Dr. Lipinski.

Additionally, while vomiting and nausea are common in pregnancy, extreme vomiting can be worrisome. “If someone is throwing up so much that they become dehydrated or lose more than 20 pounds, then that is abnormal and concerning,” says Dr. Lipinski. “It can be a sign of a condition called hyperemesis gravidarum, an extreme form of morning sickness.”

Additionally, seeing blood in your vomit, or experiencing extreme pain or fever along with vomiting, is definitely something you should seek immediate medical attention for, Dr. Lipinski recommends.

A Word From Verywell

Although throwing up mucus during pregnancy is somewhat unusual, if it’s something you are experiencing, you are not alone. Pregnancy can do strange things to our bodies, and increased mucus production coupled with morning sickness could mean that you end up seeing mucus in your vomit. This is usually nothing to worry about, but you should always report any new symptoms you are experiencing to your OB/GYN, midwife, or healthcare provider.

8 Sources
Verywell Family uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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  2. Heitmann K, Nordeng H, Havnen G, et al. The burden of nausea and vomiting during pregnancy: severe impacts on quality of life, daily life functioning and willingness to become pregnant again – results from a cross-sectional study. BMC Pregnancy Childbirth. 2017;17:75. doi:10.1186/s12884-017-1249-0

  3. Liu C, Zhao G, Qiao D, et al. Emerging Progress in Nausea and Vomiting of Pregnancy and Hyperemesis Gravidarum: Challenges and Opportunities. Frontiers in Medicine (Lausanne). 2022;8:809270. doi:10.3389/fmed.2021.809270

  4. National Library of Medicine. Hyperemesis gravidarum.

  5. Yu JL, Becker SS. Postnasal drip and postnasal drip-related cough. Current Opinion in Otolaryngology & Head and Neck Surgery. 2016;24(1):15-9. doi:10.1097/MOO.0000000000000226

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  7. Centers for Disease Control and Prevention. Sinus Infection (Sinusitis).

  8. American College of Obstetricians and Gynecologists. Morning Sickness: Nausea and Vomiting of Pregnancy.

By Wendy Wisner
Wendy Wisner is a lactation consultant and writer covering maternal/child health, parenting, general health and wellness, and mental health. She has worked with breastfeeding parents for over a decade, and is a mom to two boys.