Bajoran rattle

From Memory Alpha, the free Star Trek reference.

The Bajoran rattle is a small percussive musical instrument that plays a role during Bajoran births.

For Bajoran women, it is important to be relaxed during birth, so her relatives play different intstruments in a repeating rhythm to provide a relaxed atmosphere.

During Kirayoshi O'Brien's birth in 2373, his mother Keiko O'Brien played a Bajoran rattle. (DS9: "The Begotten")