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06/21/2021 | 5m 35s
| Video has closed captioning.
At the beginning of pregnancy, mammary glands start out like a tree in winter with no foliage. As pregnancy progresses and the body prepares for milk production, mammary glands undergo a massive tissue restructuring—like a tree in the spring. By the time a baby arrives, the “tree” is in full bloom, ready to produce and deliver milk.