EXCLUSIVE. Bust out the pink balloons – ’cause Kim Kardashian and Kanye West are having a baby girl … TMZ has learned.

We broke the stories … the baby’s due in late January by a surrogate Kim and Kanye hired for medical reasons.

Kim’s placenta accreta condition could kill her if she carries another baby to term.

This will be girl #9 in the Kardashian clan – not including Kris herself – and we’ve learned it bodes well for one of those ladies in particular.

We spoke with a notable child psychologist, who tells us North West and baby #3 will probably form a closer bond than Saint might with his new sis.

The reason’s simple: sisters gravitate to their sisters.

Kind of a bummer for Saint, though – especially since Kim recently said North “Does not like” him … and doesn’t seem to be getting past the meanie phase.