Khloe Kardashian is expecting another baby with Tristan Thompson

Through Surrogacy!!!

A different woman get artificially inseminated with father's sperm to conceive a child

What is Surrogate pregnancy?

This is usually done when the actual mother is incapable of giving birth

Khloe always wanted to have more kids

Khloe and Tristan have been together, broke up, got back together and broke up again

Both already have a child named True(4 year old)

Khloe desire to make True a big sister is documented in "Keeping Up With the Kardashians"

Khloe had took IVF treatment three times but still none of her eggs were viable