Most women have at least a few days they feel the need for shortness of breath treatment during pregnancy. That's because of hormones.
A woman's body makes massive amounts of the hormone progesterone while the baby is in her womb. Progesterone sends a signal to your brain to send a signal to your lungs to breathe more air. You will feel like you need to breathe deeper and you need to breathe more often.
Just as progesterone thickens the lining of the uterus to provide nutrition to the unborn child, it also ensures that the baby gets enough oxygen by forcing the mother to breathe more. Heavy breathing is not a sign that the unborn is in distress. The fetus receives plenty of oxygen through the placenta. But it is a natural part of being pregnant, especially after the start of the second trimester.  This deep breathing reflex ensures that both you and your baby get plenty of oxygen even if you were, for instance, to take up residence in the Andes . It acts as a kind of early warning system against falling levels of oxygen in the bloodstream .
Natural or not, feeling like you out of breath is unpleasant
The hormonal changes during pregnancy make a woman's body especially sensitive to carbon dioxide levels . Carbon dioxide levels indoors can be as much as five times higher than carbon dioxide levels outdoors . Schools, even nursery schools are prone to unhealthy, high levels of CO2 that can cause anyone, pregnant or not, to feel tired, dehydrated, and congested [6,7].
What can pregnant women do to overcome the health problems associated with excessive indoor CO2? It can help to keep your surroundings cooler than might have felt comfortable when you were not pregnant . Your body's carbon dioxide receptors aren't quite as sensitive when your body temperature is lower. Beyond that, there is a list of places that pregnant women will feel a lot more comfortable if they avoid:
- It's a good idea to avoid diesel- or gasoline-powered public transportation. CO2 levels inside a bus can be six times higher than outdoor air .
- Avoid older buildings that don't have modern HVAC systems, or that depend on windows for ventilation. If the windows are shut, indoor CO2 levels can run as high as 2500 ppm, compared to 400 ppm for outdoor air. That's high enough that your decision-making ability and and emotional stability are affected. 
And there are some "common sense solutions" that don't really help with the basic problem:
- Houseplants don't really help with the breathing problems caused by hormonal changes in pregnancy. However, they certainly make people feel better , and they also break down harmful chemicals that get into the air from household products .
- Air fresheners emit fine particles that can cause damage to your lungs that may not be detected for many years , and do nothing to decrease CO2.
Of course, hormonal changes are the only reason women experience shortness of breath during pregnancy. One often-overlooked reason for shortness of breath is dehydration. Women who drink more water during pregnancy have babies who are less likely to experience wheezing at age 18 months , and feel better while they are pregnant, too. And a very big reason women have problems with breathing during pregnancy is that they gain weight.
More specifically, women feel uncomfortable not so much because they can't inhale as much air as they need, but, paradoxically because they can't exhale completely . During pregnancy medicinal ways to manage dyspnea with drugs and medications are out of question, so what are the best natural ways to manage dyspnea with this in mind?
- When you are feeling out of breath, hold your arms out from your body. This gives your chest more room to move air in and out.
- When you feel like you just can't get enough air in, push air out. Exhale as long as you feel comfortable, up to a count of eight. When you feel that you have pushed all the air out of your lungs, take another breath in. Feel the air going deep as it will go, but only breathe in to a count of four. Or if you aren't keeping count, just make your breath in about twice as long as your breath out.
- Breathe in through your nose. Bring out through your mouth, with your lips pursed to make a small round opening.
- Do this exercise five minutes at a time, once or twice a day. And try to find at least five or ten minutes a day to focus on those things most important to you, to meditate, for maximum benefits from the breathing exercise.