Why Does Everything Smell Bad When You're Pregnant?

Smell aversions are a common symptom of pregnancy

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For some, an aversion to smells can be one of the first symptoms of pregnancy. Suddenly, the perfume you wear every day, the scent of certain foods, or aromas wafting from your favorite coffee shop might have you holding your nose and running in the opposite direction. 

Not everyone experiences a hypersensitivity to smells during pregnancy, but an estimated two-thirds of people do. Here, we quiz the experts on why some people struggle with certain smells while expecting—along with a variety of ways to cope. 

Why Our Sense of Smell Changes During Pregnancy

Whether it’s an odor that you've always found unpleasant or one that you formerly loved but now can’t stomach, smell hypersensitivity is common during pregnancy. It is occasionally referred to as hyperosmia, which is described as an overwhelming sensitivity to smells. However, few clinical studies have explored the link between hyperosmia and pregnancy, so most information medical professionals have collected is anecdotal. 

For sufferers, hyperosmia appears to be more pronounced during the first trimester and often reduces as the pregnancy progresses. Experts have theorized that this could be due to the rise and fall of pregnancy-related hormones, such as estrogen. However, another theory poses that because nasal congestion is common during the third trimester, it could help ward off hyperosmia symptoms.

“[Smell] hypersensitivity is typically noted in the first trimester and decreases as gestation continues,” says Kecia Gaither, MD, MPH, MS/MBA, FACOG, a double board-certified OB/GYN and maternal-fetal medicine specialist in New York. “It should be noted that nasal congestion occurs in the latter stages of pregnancy, reducing airflow, and therefore the ability to perceive odors.”

A condition called pregnancy rhinitis is very common in the second and third trimester and is characterized by a congested nose and cold and flu-like symptoms, which may stave off any smell hypersensitivity. "Some women will experience called rhinitis of pregnancy," says Erich P. Voigt, MD, a board-certified clinical associate professor in the department of otolaryngology at NYU Langone Medical Center. "We know it's caused by the hormonal changes that occur in pregnancy. And with that, there may be a decreased perception of smell, because the smell particles can't get through the swelling."

Why You May Notice New Smell Aversions

Without any robust studies that explore the link between smell aversions and pregnancy, experts are left to theorize why this sensitivity can occur. One common hypothesis is that smell sensitivity is nature’s way of helping protect your growing baby by repelling potential poisons.   

"One benefit of heightened smell is that it may prevent the mother from ingesting substances that could be harmful to the developing fetus," Dr. Gaither.

Dr. Voigt agrees. “The theory behind why there might be an increased sense of smell, or a perception that smells are different, may be [a] protective mechanism. Anything that could be perceived as a poison, your brain is going to say, ‘Hey, that's dangerous, get away,'" he explains. “And because smells are very complex, there may be something that could be normal and pleasurable, but your brain may perceive it as dangerous when you're pregnant.”

Common Smell Aversions

Every person’s experience with hyperosmia or smell sensitivity is unique, and not everyone will be affected by the same odor. However, common smell aversions during pregnancy include meat, coffee, perfumes, or synthetic smells.

“I realized I was pregnant when I could smell a vase of flowers a mile away,” says Sara Bodenham, a mother of four from the UK. “Then I couldn’t take the smell of meat cooking or fat frying—even the smell of my partner!”

“It was cucumber and onions for me,” adds Jenny Wong, a mother of one, also from the UK. “If I smelt onions, I had to leave the room or I would vomit. I couldn’t eat or be near them. Interestingly, my now-born son also can’t stand onions.” 

Jenny isn't alone in feeling as though her smell aversions could trigger morning sickness. Studies have made the link between hyperosmia and nausea during pregnancy. "This hypersensitivity has been noted to have a causal relationship in research studies to nausea and vomiting in pregnancy," says Dr. Gaither.

How to Cope With Bad Smells

Although unpleasant, your smell hypersensitivity will likely dissipate as your pregnancy reaches its latter stages (thank you, nasal congestion), before disappearing entirely once your baby is born. In the meantime, there are several ways to manage your new super-sense of smell. 

Avoid Triggers

If possible, try to minimize your exposure to the smells that are giving you trouble. Whether it’s a cleaning product, a particular perfume, or a type of food, try to avoid these items until your sense of smell returns to normal. 

Let in Fresh Air

Open a window to help circulate airflow, which will help move along any lingering, unwanted smells. If you work in an office, a fan at your desk will do the same thing. 

Keep a Lemon Handy

Citrus gives off an intense scent that can overpower other offensive smells. Keep a lemon on your desk or in your pocket and, when another smell becomes overwhelming, dig your nails into the lemon peel to release its fresh citrus odor. 

Be Honest

If the smell of your friend's cologne or co-worker's lunch is turning your stomach, don’t suffer in silence. If appropriate, explain your symptoms and ask for a bit of consideration until your smell sensitivity passes.

When to See a Doctor

Smell hypersensitivity can be unpleasant, but it usually isn’t any cause for concern. However, with some studies linking smell aversions to morning sickness, you should seek advice from your doctor if you feel as though your smell aversions are impacting your health. Extreme morning sickness, called hyperemesis gravidarum, can cause dehydration and malnutrition if left untreated.

“[It's important] to keep your nutrition up during pregnancy,” says Dr. Voigt. “[In the case of] severe nausea or vomiting, [you] should discuss that with [your] doctor or OBGYN to make sure [you] don't get dehydrated.”

A Word From Verywell

Suffering from smell hypersensitivity during pregnancy is normal. Although it can sometimes feel like a superpower you never asked for, it is typically nothing to be worried about. However, there is a potential link between smell hypersensitivity and morning sickness, so seek advice from your doctor if you feel that your smell aversions are negatively impacting your health.

Additionally, while suffering from smell hypersensitivity is normal, not suffering from it should not be a source of worry either. That said, if your lack of pregnancy symptoms is a concern, seek reassurance from your OB/GYN 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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By Nicola Appleton
Nicola Appleton is a UK-based freelance journalist with a special interest in parenting, pregnancy, and women's lifestyle. She has extensive experience creating editorial and commercial content for print, digital, and social platforms across a number of prominent British and international brands including The Independent, Refinery29, The Sydney Morning Herald, HuffPost, Stylist, Canva, and more