The exact cause of fibroids is unknown but they are connected with the amount of oestrogen (a hormone) in a woman's body. This explains why they normally appear during a woman's middle years (30-50) when oestrogen levels are high and stop growing after the menopause when oestrogen levels drop. They are commoner in women who have never conceived up to their middle years. Family planning does not cause fibroids.

Attribution: Marie Stopes