Can Your Birth Month Determine Your Allergy Risk?

Seasons change and with them our moods and behavior. Winters can make us gloomy and spring surely adds a cheer to our step. Seasons, it turns out, have a much greater effect on our overall well-being. Researchers are pointing out that the season of your birth may determine the allergies that are triggered in your body.

Seasonal Effect

How can the season of birth leave such an impact? In several studies it has been found that babies born in autumn and toward winter months are more likely to suffer from allergic diseases ranging from rhinitis, hay fever to asthma, eczema, and food allergies.1 This is thought to be the effect of the external environment on the fetus in the in utero phase, mainly during the first trimester. So the level of allergens like pollen outside is having an impact on the fetus while it is still in the womb. For

autumn babies,  the fetus is in the immune development phase in the spring season, when pollen levels are high. Fetal exposure to pollen is therefore higher due to higher maternal pollen exposure.

Scientific Studies

The largest study was conducted in Finland, asking around 6000 parents about their child’s birth data, food allergies, and family history.2 This was studied along with allergy treatment data from hospitals and data on pollen count throughout the year. The results showed autumn children had a 5% greater incidence of allergies, with pronounced reaction to milk and eggs as a food allergy. They concluded that children having their early gestational period in the pollen season for broad-leafed trees are more likely to develop allergies.

Several other studies, mainly across Europe, also highlight that children born in autumn months have more allergies.3

Some studies involved detailed DNA analysis, looking for the sustained effect of birth season on allergy risk.4 In fact, seasonal effect has even been linked to behavioral traits and mental health. 5

What Should Parents Know?

As a parent, keep the following in mind when you wonder about your child’s allergic reactions.

  • Kids born in autumn are more likely than those born in spring to have eczema.
  • Kids born in the autumn and towards winter months are more likely to suffer from allergic diseases ranging from rhinitis, hay fever to asthma, eczema and food allergies.
  • Several other factors also influence a child’s general allergic inclination – ranging from environmental factors like building construction and dust levels, exposure to sunlight to family history, ethnicity, and geography.
  • Kids born in other months and season are in no way completely
    immune from all allergies.


While published studies tend to highlight the connection between season and allergies, the sustained impact through adulthood is not really established. There are so many other factors in play that parents need not currently concern themselves too much. They are certainly not advised to plan pregnancy timing just to reduce allergies in their child.

Seasons change and so do the factors contributing to the allergies so while birth-season is a factor, it’s not the only one!