A man's been charged, after a baby was hospitalised with multiple fractures in Upper Hutt

The three-month-old girl was admitted to Hutt Hospital in June, with nine fractures including across her ribcage - and ankle and upper arm.

A 23-year-old man's charged with four counts of assaulting a child, relating to the more minor injuries the baby sustained.

Detective Senior Sergeant Steve Wescott says they're committed to establishing the full circumstances of how the more serious injuries were inflicted.

The man is due in court at the end of the month.