Many parents use pregnancy as a good time to educate themselves on parenting, health, and more. It’s a useful time to prepare for the new addition whether it’s your first child or even your third child!

A lot of parents ask the questions, “What should we avoid during pregnancy?” or “What harms a baby during development?” There are a lot of things that can potentially cause harm to an unborn baby.

Drugs and other dangerous lifestyle habits are towards the top of the list when it comes to health risks during pregnancy. One topic that is often overlooked is your indoor air quality.

Oftentimes when people think about pollution, they consider outside sources of air pollution. Things like vehicle emissions, factory output, chemicals, and more, all contribute to the outdoor air quality. But what about indoors?

Research shows that indoor air quality has a direct impact on the health of expectant mothers and their growing babies. (And don’t forget about dads and other family members, too!)

People usually try to improve their indoor air by adding things like humidifiers, purifiers, and more. However, if your HVAC system is dirty or not properly maintained, additions to your HVAC system won’t matter if you don’t address the source.

Despite all the options of home heating and cooling equipment, indoor air quality is an important factor in everyone’s health – especially babies and their pregnant mothers!

How does indoor air quality affect pregnancy?

There are a lot of things that can cause unhealthy outcomes during pregnancy. Sometimes these issues arise during pregnancy, while others may take longer to show themselves- such as during early childhood or even become chronic problems into adulthood.

Preterm Labor

When mothers go into labor before the 37th week, it can be reason for concern. Babies born before they are fully developed are at risk for developing permanent disabilities or health issues.

There are a variety of reasons that babies can be born premature, but poor indoor air quality shouldn’t be one of them. Multiple studies have been conducted that show that indoor air pollution can cause preterm labor and birth. Exposure to these harmful air contaminants have been shown to be a contributing risk factor to pregnant women and premature labor.

Delays in Development

Poor air quality has been shown to cause delays in childhood development. The Harvard School of Public Health conducted a study in 2014 which showed that pregnant women exposed to “high levels of fine particulate matter” during the end of their pregnancy showed up to 2x the risk of having a child later diagnosed with Autism Spectrum Disorder than other women who were not exposed to the same poor air quality.


With research supported by the National Institute of Health, scientists conducted a study in 2018 which concluded that, “…short-term exposure to elevated levels of air pollutants was associated with higher risk for spontaneous pregnancy loss.”

What Studies Have Shown When It Comes To Pregnancy Vs. Pollution

Overall these studies have shown a direct correlation between poor air quality and health concerns during and after pregnancy. More research is needed before we can draw a definitive line between these issues and their causes and long-term effects. However, we do know that substantial evidence exists which shows that poor air quality has the potential to cause significant issues before, during, and after birth.

A lot of these studies have used outdoor pollution as the contributing factor. However, we also know that the air we circulate indoors comes from our outdoor air. Furthermore, indoor air is even more polluted than outdoor air. With people spending up to 90% of their time indoors, this is even more cause for concern.

The Environmental Protection Agency (EPA) “the air within homes and other buildings can be more seriously polluted than the outdoor air in even the largest and most industrialized cities.”

One of the main sources of poor indoor air quality is underperforming ventilation. In previous decades, buildings were constructed with energy efficiency in mind, essentially limiting ventilation in order to improve efficiency. These old building standards have since evolved, however we frequently reside and work within buildings that were constructed during these previous building codes. The new standards set forth by the American Society of Heating, Refrigeration, and Air Conditioning Engineers require companies to utilize an improved airflow rate.

When air is unable to properly circulate between indoors and outdoors, that means that pollutants and contaminants within our walls have a more difficult time escaping. When this harmful pollution is trapped inside, it can build-up and become worse and worse.

How Does Outdoor Air Enter My Home?

There are three ways in which air flows indoors from the outside.


Mechanical Ventilation

Natural Ventilation

Infiltration means that air is able to enter your home through arbitrary means – such as cracks in window seals, doors, floors, ceilings, joints, etc. Mechanical Ventilation is a method such as vents, ventilation fans, and air handlers. Natural Ventilation is what occurs when we open our windows and doors for some “fresh air”.

When you have inadequate ventilation, that causes a buildup of indoor air pollution. The effects of poor indoor air quality are similar to common colds and other illnesses, so it’s important to be mindful of if your symptoms are present at all times, or only when you’re at home. This can be a major red flag when it comes to identifying whether or not your symptoms are directly caused by indoor air pollution. Your HVAC company can usually conduct a test on your indoor air quality and tell you what kinds of contaminants are lurking in your home’s air. In addition to testing, they can work with you on finding a solution to what you find from the results.

HVAC Systems and Poor Air Quality

It’s also important to remind you that just because you aren’t experiencing symptoms on a regular basis, doesn’t mean that the danger is not there. Some of the effects of air pollution don’t show up for many years – just slowly causing your body to become sicker and sicker due to prolonged exposure. These air quality concerns can come back later and present themselves in the forms of cardiovascular diseases or even cancer. Source: and

Your HVAC system is one of the most significant barriers between air pollution and your health. If you have a system that is operating optimally and you have it maintained regularly, you will be much healthier (and have more peace of mind) than someone who is just guessing that their system is doing its job on its own. The heating and cooling system and your ductwork is what does the heavy lifting when it comes to effectively filtering out contaminants from your home’s air.

It’s important to ensure your heating and cooling system is operating properly and is cleaned professionally. Build-up of dust, pollutants, and more can not only create health risks, but cause early equipment failure and breakdown.

Not only does regular maintenance of your HVAC system improve your air quality, it can also give you peace of mind when it comes to your budget. During pregnancy a lot of people consider their budgets and how to provide the best life possible for their new addition. If your system is properly maintained by your HVAC company, you will know that you are doing all you can to prevent equipment breakdowns and unexpected repair expenses.

Air Quality And Pregnancy

Overall, remember that the air you breathe is just as important as the foods you eat and beverages you drink. The air you take in is equally important to your unborn baby’s health, too.

Your HVAC system is the source of your indoor air quality, and it’s imperative that you understand it’s direct effect on your health. Welcome your baby into a happy, healthy home with proper indoor air quality. If you have questions on how we can help you prepare your home for your new baby’s arrival, call or email us anytime and we’d be happy to set up a time to talk with you about how we can immediately get to work improving your indoor air quality at home… And congratulations on the new baby!

You can reach us at: 937-439-4696 or [email protected]