11 Apr Body changes in pregnancy
Your body is working hard, even before you move; just because you are growing another little person.
Your blood volume increases by a whopping 50%.
But your red blood cells only increase by 25%.
Your heart and lungs work harder to enrich your blood with oxygen. Each pumping of the heart deals with a larger volume; about 40% more. And the heart rate increases to cope with the larger volume; to about 90 beats per minute.
About half of the blood volume goes to the placenta.
As the baby and uterus grow, they expand upward and outward. A single baby has filled the pelvic cavity by week 12 and is pushing up into the abdominal space. It has reached navel height halfway through the pregnancy. Baby is tickling the bottom of your diaphragm by week 36. Baby moves back down into the pelvic cavity in preparation for birth in the pelvic cavity at week 38. This is called engagement.
You can see your abdomen expanding and may notice separation of the rectus muscle in the midline. If you notice a bulge, roll onto your side when getting in and out of bed. Use your abdominal core muscles to hold your baby into your spine, when you sneeze and when you get into and out of chairs.
From about 34 weeks, some women experience breathlessness ad the contents are pushed upwards and the pressure is on the base of the lungs. You may feel breathless at times because of the physical pressure.
Your core temperature rises because of the extra weight and blood volume and the work associated with this. Your internal thermostat works hard to keep you cool. You may find you are sweating more and are thirstier.
No wonder a lot of women feel breathless when doing exercise. Exercise during pregnancy should take this into consideration. Aim to breathe comfortably throughout exercise. If you begin to feel uncomfortably hot or breathless, please slow down. It is faster for you to cool down than for your baby to cool down.
And remember exercise is good for you and your baby – just go gently.