The risk of developing fibroids increases with age, and women who gave birth to their first child at 35 years or older are at a higher risk. Interestingly, women who have never given birth also have a high risk of developing uterine fibroids.
Even though pregnancy is a risk factor in fibroid development, Dr Lin said that some epidemiological studies have found that being pregnant can reduce the risk of fibroids due to the womb shrinking after delivery.
Genetics plays a role too – if your mother had fibroids, you are three times more likely to get them, according to the United States government’s Office on Women’s Health.
A study by the University of California last year found that African-American and East Asian women (those from China, Japan and Korea), have a higher risk of developing fibroids than women of other ethnicities, possibly due to a genetic predisposition that affects how oestrogen is metabolised by the body.
“[Asian women] also tend to develop fibroids at a younger age, and the fibroids that they develop may be larger and more numerous,” added Dr Lin.
Another factor is obesity. The risk could be two to three times greater than average. “Obesity is associated with higher levels of oestrogen, which may contribute to fibroid growth,” said Dr Lin.
THE LINK BETWEEN FIBROIDS AND FERTILITY
Uterine fibroids may affect one’s reproductive health, said Dr Phoon.
For example, large fibroids located near the fallopian tube or cervix can hinder conception as they physically obstruct the passage of the sperm, Dr Lin explained.
Fibroids located within the uterine wall may alter uterine contractions and impair the movement of sperm, or interfere with transporting the embryo to the implantation site, he added.
At the same time, large fibroids can also cause reduced blood flow and oxygen to the uterine lining, which can impair its healthy development for successful implantation. It can also cause “irregular menstrual bleeding or heavy menstrual period, which may further diminish the chances of conception”, said Dr Lin.
Removing the fibroid then improves the overall health of the uterus, making it more conducive for pregnancy.
However, not all women who have uterine fibroids will struggle with infertility. If the fibroids are located on the outer surface of the uterus, the chances for a successful term pregnancy are high, said Dr Phoon.
