Hi, I have a almost two year old female Yorkie I bred with my male. She weighs in at just over 4 lbs. and my male at 3 lbs. My female ended up in the hospital with an emergency c-section and it cost me over $2,000- to pay the bill and they would not preform any surgery until I paid the bill in full. My girl had to be fixed in the process of it all and two puppies did not make it through the ordeal. My Trini could have died! and so can your baby. I am still planning to breed because it is my passion and I recently purchased a puppy female, who should grow to be over 5lbs. I am going to skip her first heat and maybe her second because I was informed that she should be at least 1 1/2 to 2 years old before I breed her and I will spend the next year while she is maturing doing even more research on breeding Yorkies. (I have honestly put in a few hundred hours already) Be careful...do not do it yet!