Research has shown wintertime babies do not fare as well as their spring, summer and fall counterparts.
The question is, why?
Two Notre Dame economics professors wondered the same thing and went nationwide looking for the answer.
Dan Hungerman and Kasey Buckles found through their research that babies born in January, February and March are less educated, earn less money and die earlier.
"What we're actually doing is asking how children born at different times of year might be different at birth," said Kasey. "And we think an important way that they're different is that they're born to different types of families."
"Past work has argued that children born in the winter have lower wages because they get less education," said Dan. "We're showing that children born in the winter are often born to women of a lower socioeconomic status and that fact might explain both the education result and the wage result."
Access to millions of birth certificates greatly helped their research.
"We got data on almost every birth certificate in the United States in the 1990's," said Dan. "So we have data on over 50 million births.
"We learn about the mother's education, race, marital status, age, and some information on her health as well," said Kasey.
Meaning there are factors that many who have wintertime babies face.
"Women who give birth in the winter are more likely to be without a high school degree, they're more likely to be non-married, they're more likely to be teenagers than other women," said Dan.
The birth certificates they were able to access were rich in information about a mother's lifestyle.
"We find that these differences are found in many different parts of the country, so it is not really just a story of women in one part of the country," said Dan.
"By using this large amount of data we were able to pick up these differences in the maternal characteristics," said Kasey.
They also found women of higher economic status often plan not to have a baby in the winter.
"We're finding that the average mom who gives birth in winter is of lower socioeconomic status and that means that in many cases the average child starts off in a worse socioeconomic position," said Kasey.
Weather factors into the equation.
Heat lowers sperm count, so women of lower economic status are less likely to have air conditioning and less likely to conceive in the heat of the summer.
And while the season of birth outcomes has been studied before, these Notre Dame economists believe their findings are unique.
"Really it's who your mother is, not so much when she gives birth to you that really seems to matter a lot," said Dan.
The study also points to the need for good pre-natal care, a good diet and avoiding drugs and alcohol.