Category: superpowers

The nose knows


Fellow scientist and good friend, Dr. C, has already made her way through this whole pregnancy thing and has been my sounding board for all things bump related.  I must admit, I am extremely jealous of those pregnancy superpowers – super smell, super taste – bestowed upon many a pregnant lady that seem to have missed my expanding body.  But then again, if this oversight also provided that sweet bypass from the cookie-tossing gods, I will take it. 

Dr. C., however, was lucky… or not so lucky… to have experienced the full on rewire –


It’s a bird! It’s a plane! No, it’s a heightened rhinological olfactory manifestation!

Or, in plain English, a heightened sense of smell…

Honestly, I think my nose knew I was pregnant before I did.

It was a beautiful, San Diego Saturday. I was relaxing on the couch working on my computer (a.k.a. guiltily watching the latest reality show…), when my husband decided to make himself a tuna fish sandwich.

Within moments of opening the tuna can, the fishy aroma hit me like a Mack truck. I ran for the bathroom and promptly threw up in the toilet. And a little around it.

“Whoa. It must have been something I ate,” I said to a very surprised husband…

It wasn’t until weeks later I figured out that I was pregnant.  By then, I could, from our apartment, smell what our neighbors three doors down were having for dinner.

Was I imagining it?

Much like a spider bite gave spiderman his spidey sense, did a German shepherd bite me?

Target knew I was pregnant before I did, too. I started to get all these coupons for diapers and nursery furniture. I have no idea what changed in my buying habits to tip them off, but one secret experts posit is that expectant moms tend to opt for the scent-free lotions! [1]

So, what is it about smell that changes for pregnant women?

In a study by the National Geographic Smell Survey [2], a whole bunch of women (290,838 women to be exact, of whom 13,610 were pregnant) reported on their sense of smell. The pregnant women claimed they couldn’t smell as well as those that were not pregnant, yet they performed better on one of the smell tests they took.  More recent studies showed that women did self-report to have a better sense of smell while pregnant [3] [4], or at least experienced a change in smell [5].

But what yours truly says to all of those studies is: brave be the soul that can endure the smell of pungent fish while pregnant.

So, how and why do we get these super smell powers when we’re expecting?

During pregnancy, the hormone estrogen increases to help with a whole host of events that occur.  It’s been shown that it is this increase in estrogen that activates that crazy smell superpower.

Why? Back when we were all running away from the dinosaurs (ok, that never really happened, but a looong time ago), a heightened sense of smell may have been beneficial to the health of mama and baby. Those that ate the stinky, spoiled foods or other such toxic agents got very sick, couldn’t maintain pregnancy, or even died. Those that could smell out bad food and avoid it lived, passed on this beneficial smell trait to their daughters, who had daughters that could smell, who had daughters that could smell, and so on.

Because of this, women in general, as compared to men who maintain lower levels of estrogen, are supposed to have a better sense of smell and of taste. After all, taste is very much linked with smell [6].  Think about it – your nasal passageways and your mouth are connected – which you most likely tested unknowingly as a child when you drank chocolate milk, laughed, and it came out of your nose.

With that appetizing thought…

Have you ever watched the Food Channel? Whenever they have those awesome cooking competitions, sometimes the women judges disagree with the guy judges about which competitors’ pistachio-encrusted crème brulee tasted better. The women judges will proclaim themselves, because they are women, as having the more sensitive palate (and thus are right about their choice of most delectable brulee).

Gentlemen, I’m afraid the ladies have you on this one. Ten points for estrogen!

So, in this sense, when women get pregnant and have what an old science teacher of mine called “oodles and gobs” of estrogen, their smelling and tasting powers cannot be rivaled.

In fact, my pregnant ladies, you make the best wine tasters! Now, stay with me here – wine connoisseurs from Tesco’s HQ in Hertfordshire claim pregnant women make the best tasters [7]. They even put out a nationwide call for pregnant women to help them with in-store tasting and called it, Operation: Cot du Rhone!

Of course, some doctors came out of the woodwork shouting, “Alcohol BAD!” [8];

But back to the big picture: whether a pregnant woman’s heightened estrogen and associated sense of smell leads her to puke at a whiff of tuna or become the greatest wine connoisseur in the land, I think we all can genuflect in awe and wonder for these newly (and temporarily) acquired superpowers of the Nose.


1. Hill, K. How Target figured out a teen girl was pregnant before her father did. 2012. Forbes.

2. Gilbert, A.N., Wysocki, C.J. 1991. Quantitative assessment of olfactory experience during pregnancy. Psychosom Med. 53:693-700.

3. Cameron, E.L. 2007. Measures of human olfactory perception during pregnancy. Chem Senses. 32:775-782.

4. Ochsenbein-Kolble, N., von Mering, R., Zimmermann, R., Hummel, T. 2007. Changes in olfactory function in pregnancy and postpartum. Int J Gynaecol Obstet. 97:10-14.\

5.  Nordin, S., Broman, D.A., Olofsson, J.K., Wulff, M. 2004. A Longitudinal Descriptive Study of Self-reported Abnormal Smell and Taste Perception in Pregnant Women.” Chemical Senses. 29:391-402.

6. Kuga, M., Ikeda, M., Suzuki, K., Takeuchi, S. 2002. Changes in Gustatory Sense During Pregnancy. Acta Otolaryngol. 122:146-153.

7.  Sample, Ian. 2004. Do pregnant women really make the best wine tasters? The Guardian.

8. Tesco wine tasting plans slammed. 2004. BBC.