Interesting, their is also a big difference of % premature births between rich countries up to a factor of 3: https://obgyn.onlinelibrary.wiley.com/doi/full/10.

Interesting, their is also a big difference of % premature births between rich countries up to a factor of 3: https://obgyn.onlinelibrary.wiley.com/doi/full/10.1111/1471-0528.14273 https://obgyn.onlinelibrary.wiley.com/doi/full/10.1111/1471-...