Kim, Kris, Kourtney and Kylie are heading back to L.A. after being at Lamar Odom's bedside since Tuesday ... but Khloe refuses to leave her estranged husband.
We're told Kim has an appointment with a pregnancy specialist who flew to LA just to meet with her. She's had an ongoing condition in which her placenta is growing too deep into her uterus.
They all left on a private jet.
Kendall, who's in London, is on her way to Vegas to be with Khloe.
The entire family plans to head back to Vegas this weekend to be with Lamar.