I know someone who was the size of an adult hand when he was born. He wasn't expected to live. His parents kept him in a shoebox inside the oven in Vietnam. This is not a joke. He's now about 6', a father, and a student in dental school with a Ph.D. in pharmacology.
My grandmother's sister was also a preemie, born on a farm in rural Indiana. Her bed was a shoebox on the oven door. My great-grandmother could slip her wedding ring over the baby's fist. Aunt Vi is now in her nineties.
My mom was about that size. She was born on a farm in Texas in 1912; they placed her in a shoe box and put her by the fire place. No doctors around. After working to save my grandmother, her aunt thought to look at the baby to see if it was still alive...and she was! They gave her sugar water to survive. She was so small, when you placed a tea cup over her head, it completely hid it. She lived to marry and have two very healthy children.
I know that isn’t a joke! My Grandmother was born very early (the story is DGGM was 7.5 months when she delivered) and the Dr told them to keep her warm and pray for the best. They kept her wrapped is blankets and placed her in a small wooden box that they layed warmed bricks under and mirculously she survived and I am here today.