No, that’s not the case. As hens grow and mature, the size of the eggs they lay naturally changes. When a young hen first starts laying, her eggs are quite small for the first five to six weeks. After that, they stay medium-sized for a while. As the hen gets older, larger and very large eggs become the norm.

A fun fact is that the yolk size is almost the same in both medium and large eggs. The main difference is simply more egg white in the larger egg.