You can import makehuman models directly into UE4 however if you want to retarget the Animation Starter Pack assets, the pose will never be quite right.
Follow this guide to remedy this.
If any stage is unclear to you, you can watch the youtube video.
Paste in the python script from Github.
Close the Retarget Manager. On the left, check the 'Show Advanced Options' checkbox.
We want all bones below pelvis to be in Skeleton mode. The easiest way to do this is right-click pelvis and choose 'Recursively Set Translation Skeleton.' Then set pelvis back to Animation.
NOTE: In UE4.14 and later this step is skipped.