In addition to regular particle systems, UE4 supports GPU particles. From Epic:
"GPU Sprites are particles that have most of their calculations throughout their lifespan passed on to the GPU rather than the CPU. They provide the benefit of supporting significantly more particles per system than traditional CPU particles."
GPU particles also allow for the use of vector fields. To get these into Unreal Engine, you need to import them from Maya using the UE4 Vector Field Exporter. The video below walks you through the steps necessary to do so:
I'll be posting a few more examples, but here is a screen grab of my first particle system using vector fields created in and imported from Maya.