Life Expectancy

Do you think that life expectancy in our day and age should really be attributed to Medical advances or should the decline of the infant mortality rate be attributed to Medical advances. I am pretty sure that people who survived birth and childhood in past centuries lived into their 70-80's, but when you try to average it out and have to include deaths at birth it brings the average life span down a bunch. I was thinking about this because the bible mentions people who had long life spans outside of the first few chapters of Genesis. Anna is a great example. Anyway. I always thought as a kid that our medicine had made some spectacualar leap for mankind by creating the perfect anti-death agent. It turns out that we are just more proficient at delivering babies - no small feat in itself, but quite different from making someone live who would have lived 30 years live for 80. Just a thought...