There is an increasing trend of women opting for a C-Section during childbirth, especially in the western world. This has led to more babies being born that have larger heads (the main reason why a C-Section is required during delivery). However, women’s birth canals haven’t adapted to this change leading to more C-Sections and hence more big headed babies being born. It’s a cycle that has repeatedly been in motion since the rise of C-sections in the US since the 1950s and 60s.