Fibroids are masses that originate from the uterine muscle, have a very low probability of becoming cancerous, and are therefore considered “benign”. They are seen quite often in women and therefore are also common during pregnancy.
At least one fibroid can be detected in four out of 100 expectant mothers on ultrasound.
Fibroids are more common in mothers who have experienced their first pregnancy. Although they are usually one, they can be more numerous.
As the expectant mother gets older, the likelihood of fibroids during pregnancy increases.
Fibroids may be in close adjacency to the inner layer of the uterus (submucous type), may be located entirely within the uterine muscle (intramural type), or may be located entirely on the outer surface of the uterus (subserous type).
Fibroids may be the cause of inability to conceive in rare cases, but they are more important in terms of possible problems that may occur during pregnancy, and an expectant mother who is known to have fibroids should be followed more closely.
The diagnosis can be made in an ultrasound performed during the non-pregnant period, or it is often made in a routine ultrasound examination performed in the first trimester. Especially posterior wall located fibroids are difficult to recognize in the later stages of pregnancy.