Yes. Yes, especially if they are very large growing inside of the uterine wall, or growing in the endometrial lining. Surgical removal is usually quite successful. Remember though only 10-15% of all fibroids cause infertility.
Yes. Fibroids can definitely affect pregnancy rates. Fibroids that are submucosal (into the area where a pregnancy would implant) seem to decrease pregnancy rates and increase miscarriage rates. Fibroids that are in the muscle only seem to decrease pregnancy rates by a smaller amount. But usually fibroids are not bad enough to completely prevent pregnancy.