All hospitals rely on donations to help cloth stillborn babies. Blankets and hats are also used in the NICU ward for premature babies who survive birth.
You can find many charities who require help through sewing, crochet, knitting, donating of items or even money donations.
Here’s a list of some in the UK
Little Angel Wings– Knitted items only
Here’s some resources for making and donating however if you wish to help a charity they may have their own patterns and links: Making Items Links to all free knitting, crochet and sewing links I could find.