A submucous fibroid bulging into the cavity of the uterus, can prevent the uterine musculature contracting in the area surrounding the fibroid.  This is because the normal tissue has been pushed aside. As a result, the arteries in this area will remain open. When this occurs, a woman will hemorrhage, pass large clots, and have a period that lasts up to fifteen days. She can become severely anemic and often will feel weak, faint, and unable to go about her usual activities. The longer this continues, the worse it becomes, because as the tumor grows, more spiral arteries become involved and the heavier she will bleed. [ x ]

Regular ultrasound is not the best way to determine exactly where fibroids are. For this information, MRI is best, but most expensive. Hysteroscopy (looking in the cavity with a small telescope) and saline-infusion sonography (ultrasound after sterile water is placed into the uterine cavity) are also very good. [ x ]

Fibroids are muscle tumors that originate in the wall of the uterus and grow under the influence of estrogen.  It is known that a genetic error in the gene that controls the rate of replication for uterine muscle cells must be present for fibroids to develop.

In response to erroneous instructions from this gene, the uterine muscle cells begin to replicate at a tremendously accelerated pace, and before long, the cells begin to pile up on themselves as tiny seed-like growths. Eventually, the additional cells can no longer be incorporated into the body of the uterus. At some point in this process, the cells lose their identity as normal-looking muscle cells and become fibroids. [ x ]

For many years gynecologists believed that only submucous fibroids interfered with pregnancy. However, a number of recent studies have demonstrated that women who were previously unable to conceive also became pregnant after intramural of subserous fibroids were removed. [ x ]

No science just yet... [ x ]

No science just yet... [ x ]

When women are in their forties, their fibroids may undergo a growth spurt in response to a change in hormone balance.  At this time in their menstrual life, they often produce more estrogen than normal, because progesterone, the ovarian hormone that inhibits the effects of estrogen, is diminished.

At menopause, when the ovaries stop producing estrogen, fibroids will stop growing. In time, they may shrink and, sometimes, disappear. [ x ]

Until recently, surgery was the only treatment option, however in the past 10 years; a new non-surgical procedure has been introduced to treat fibroids. This procedure uses embolisation to close blood vessels, which nourish the growing tumour. By severing the tumours blood supply, the fibroid shrinks usually within 2 months.  [ x ]

The effect of pregnancy on fibroid growth probably depends on individual differences in the genetic changes in each fibroid and the type and amount of growth factors that are present in the blood. 

If the fibroids grow to where they are extremely large, they can cause some complications, including postpartum hemorrhaging.  If the fibroids grow in such a way that they obstruct the birth canal, they can create difficulty with labor, including a stalled labor or the need to have a cesarean section. Sometimes, fibroids that grow in the uterus can cause the baby to be in a strange position, and can cause fetal malpresentation.

An ultrasound study of pregnant women with fibroids found that 69% of the women had no increase in the size of fibroids throughout the pregnancy. In the 31% of women who had an increase in size, it usually happened before the third month. Almost always, fibroids shrink after delivery.  [ x ]