Week 25: Breathing practice

Baby Bear is now about a pound and a half and gaining some baby fat. Her skin is turning pinker because small blood vessels, called capillaries, are forming under the skin and filling with blood. Later this week, blood vessels will also develop in her lungs, bringing them one step closer to full maturity. But, the lungs are still too undeveloped to sufficiently send oxygen to the bloodstream and release carbon dioxide when she exhales.

The lungs aren't the only system that's gearing up for air intake. Baby Bear's nostrils are starting to open this week. This actually allows her to begin taking practice breaths.