Ignaz Semmelweiss identified a critical link between hygiene practices and maternal mortality rates by comparing two hospital wards. He discovered that women attended by midwives had lower mortality rates than those attended by doctors. This difference stemmed from doctors transitioning directly from dissecting corpses to treating pregnant women without adequate disinfection, leading to infections in the vulnerable postpartum womb, which was akin to an open wound. Semmelweiss proposed the use of carbolic acid for sanitization before medical procedures, dramatically reducing mortality rates. However, his revolutionary findings were met with skepticism and resistance from the medical community of his time.