Kim K.’s big sis is set to give birth very soon, and she was all ready for a water birth for baby number two. However, something happened earlier this week that has completely changed her mind on that one. Details below.

Marisa Mendez

Our Kardashian sources tell us … Kourtney and baby daddy Scott Disick heard water birth is better for the baby because it’s a less shocking transition from the womb. Water births are often done without administering drugs … which some experts believe is also safer for baby and mom.

Kourtney has a friend who gave birth a few days ago and she allowed Kim’s sis to witness the blessed event. So Kourtney was ringside when the mother screamed like a mutha as she reared back and pushed in a tub of water.

Kourtney told friends it was “horrific” … “looked brutally painful” — and that was all she wrote.

So KK has decided to give birth Beyonce/Jessica Simpson style — in a mega-suite at a fancy hospital.

Kourtney, who is due any day, will deliver her baby epidural style at Cedars-Sinai.

tmz