Pregnancy: Where your breast milk starts

How do your breasts change during pregnancy? And when do they start making milk for your baby? Our video explains what’s going on.

Discover what makes your breasts unique human organs, and how it’s only during pregnancy and lactation that they become fully mature. We’ll show you how your breast structure changes, with a complex web of branching milk ducts forming within it, and special tissue converting into milk-producing cells. We reveal just how much your breasts might grow while you’re pregnant – and the truth about the relationship between how much milk you make and your bra size!