Shortness of breath

Shortness of breath during pregnancy: Explanation and tips

The feeling that you are short of air even after minimal exertion, such as climbing to the second floor, can be unsettling. However, shortness of breath (dyspnea) is an extremely common symptom experienced by about 75% of pregnant women. In most cases it is a physiological norm, not a sign of heart or lung problems.

Causes of shortness of breath at different stages

The mechanism behind shortness of breath changes depending on the trimester.

• First and second trimesters. In early stages your belly is still small and cannot press on the diaphragm. The main "culprit" here is the hormone progesterone. Its level rises rapidly and it directly affects the respiratory center in the brain, increasing its sensitivity to carbon dioxide. As a result the brain sends a signal to breathe more frequently and deeper to provide the growing fetus with enough oxygen. You may feel this as a need to take a deep breath even while at rest. This is an adaptive mechanism that works for the benefit of your baby. Read more about this period in our reviews of the first and second trimesters.
• Third trimester. In later stages a powerful mechanical factor joins the hormonal one. Your uterus reaches a considerable size, rising high into the abdominal cavity and beginning to press on the diaphragm — the main breathing muscle. This limits the space for full lung expansion, so each inhalation becomes less deep. To compensate, you start breathing more often. Good news: a few weeks before delivery, when the baby’s head drops into the pelvis (especially at 36‑38 weeks), pressure on the diaphragm decreases and breathing becomes noticeably easier.

Is the baby getting enough oxygen?

This is the main question that worries mothers. The answer: yes, it is sufficient. Physiological shortness of breath in pregnancy is discomfort for the mother, but not a problem for the baby. Your body is very smart: it adapts and supplies the fetus with everything it needs through the placenta, even if it feels like you cannot take a breath. A key role is played by regular prenatal care, during which the doctor monitors the baby’s condition.

It is important to distinguish physiological shortness of breath from signs of anemia or cardiovascular problems, which should be reported to a doctor.