The Heightened Sense of Smell During Pregnancy

· February 24, 2019
During gestation, it's normal for women to experience an increased production of the hormones that have to do with the sense of smell. In most cases, this produces nausea and vomiting.

Some future mothers experience a heightened sense of smell during pregnancy. This tends to occur during the first trimester and may cause different consequences in a woman’s health.

In some cases, women perceive unpleasant smells that are actually nonexistent. These olfactory hallucinations are a phenomenon known as phantosmia.

When women perceive smells with a great deal of intensity, the condition is known as hyperosmia. In both cases, women may experience nausea and vomiting.

Among those smells that may cause nausea and vomiting are the following:

  • Perfume.
  • Alcohol.
  • Coffee.
  • Cigarrettes.
  • Spicy foods.
  • Raw chicken.
  • Soaps and detergents.
  • Fish.
  • Certain floral smells.

Causes of a heightened sense of smell during pregnancy

This reaction occurs as a result of a progressive increase in certain hormone levels produced by pregnant women, as is the case with progesterone and estrogen. This produces an  unpleasant sensation of disgust and incites stomach discomfort.

In general, the senses of smell and taste work together. This has to do with their connection. So then, given the heightened sense of smell during pregnancy, women often present nausea and vomiting.

The Heightened Sense of Smell During Pregnancy

The increase in the hormone levels mentioned above during pregnancy is a protective defense mechanism. In other words, the pregnant mother defends herself against substances that could be toxic and even harmful to the baby’s development.

The way in which a woman’s body defends itself from unpleasant smells during pregnancy is to produce nausea and vomiting. However, when this becomes constant, the vomiting itself becomes harmful and can even be fatal for the baby. 

When a woman throws up repeatedly, the walls of her stomach contract and press against the placenta where the baby is developing. This can have a negative effect on her baby’s development.

Recommendations to avoid discomfort

Pregnant women who experience a heightened sense of smell and have already detected what smells put them off should take measure to avoid them. Below is a list with some recommendations:

  • Avoid very enclosed spaces: This is especially true of spaces that are prone to accumulate unpleasant smells or even gases that can be harmful to both mother and baby.
  • Don’t open products made with strong-smelling chemical substances. For example: Paints, cleaning products for dress clothes, and whiteners, which can even be fatal when inhaled.
  • Cut down on preparing meals. In general, pregnant women can’t stand the smells that certain foods or ingredients give off. This is especially true during the first trimester of pregnancy.
  • Avoid getting too close to people who are smoking, or have been smoking.
  • Find out what smells bother you the most. That way, you can be prepared and take your favorite aroma along with you to counteract any bothersome smell.

“This reaction occurs as a result of a progressive increase in certain hormone levels produced by pregnant women, as is the case with progesterone and estrogen”

Should I be concerned?

25% of pregnant women experience a heightened sense of smell during their pregnancies. This tends to appear and disappear suddenly.

For pregnant women, it’s normal for certain smells to produce disgust and discomfort. This occurs much more frequently during the first trimester of pregnancy.

The Heightened Sense of Smell During Pregnancy

All this being said, the situation stops being normal when the nausea and vomiting caused by odors carries on into the following months. This can be harmful for mothers as well as their babies.

If you’re done with your first trimester of pregnancy and are still experiencing these issues frequently, you should see a specialist as soon as possible. Remember that the effort your body makes when you throw up can affect your baby’s well-being.

As a final piece of advice, try to enjoy each stage of your pregnancy to the fullest, with its ups and downs, despite the uncomfortable parts. The reward after 9 months will be irreplaceable.

  • Bernardita Carrillo V, Vicente Carrillo A, Andrés Astorga V, Diego Hormachea. Diagnóstico en la patología del olfato: Revisión de la literatura. Rev. Otorrinolaringol. Cir. Cabeza Cuello 2017; 77: 351-360.
  • Trastornos del olfato. DEPARTAMENTO DE SALUD Y SERVICIOS HUMANOS DE LOS EE. UU. Institutos Nacionales de la Salud. Instituto Nacional de la Sordera y Otros Trastornos de la Comunicación.