This is not something I've spent much time looking into. When my friends mentioned their health problems to me, which happened roughly all at the same time as I was visiting family and friends in another state, I was motivated enough to read up on what the heck fibroids are (I had never heard of them) and at least do some plausibility checks on what they were saying the doctors told them.
What I came up with in my cursory reading is hormonal birth control increases levels of the very hormones complementary to the growth of a fetus which also happens to help other things like fibroids/polyps/tumors whatever in the area to grow.
I don't know that one can make the claim that the hormonal birth controls cause fibroids or cancer, as in increases the probability of these things developing. The trouble is once something like this is present, the birth control hormones make them grow larger and faster.
After a quick google search just now I found [1], which states:
"To help prevent more growth of the fibroid, your doctor may recommend that you stop taking birth control pills or hormone replacement therapy. But in some cases, your doctor may prescribe birth control pills to help control the bleeding and anemia from fibroids, even though the hormones may cause fibroids to grow."
I think there's a lot of mixed information out there and probably a lot of suppression from the industry going on, because of course there's a lot of money to be made in prescribing hormonal birth controls.
If I had a teen-aged daughter, given what I've come to understand about hormonal birth control, I'd consider a copper IUD.
[1] https://www.webmd.com/women/uterine-fibroids/understanding-u...