Fibroids and Your Fertility

Posted on 26. Apr, 2010 by David Kreiner, MD in Tubal Disease

Fertility is dependent upon so many things!

We must have healthy gametes (eggs and sperm) capable of fertilizing and implanting in a uterus with a normal endometrial lining unimpeded by any uterine or endometrial pathology. The sperm need be in sufficient number and capable of swimming up through a cervix which is not inflamed and provides a mucous medium that promotes sperm motility. The eggs need to ovulate and be picked up by normal healthy fimbriated ends (finger like projections) of the fallopian tubes. The tubes need to be covered with normal micro hairs called cilia that help transport the egg one third of the way down the tube where one of the sperm will fertilize it.

The united egg and sperm (the “conceptus”) then needs to undergo cell division, growth and development as it traverses the tube and makes its way to the uterine cavity by the embryo’s fifth day of life at which point it is a blastocyst. The blastocyst hatches out of its shell (“zona pellucidum”) and implants into the endometrial lining requiring adequate blood flow.

And you wonder why getting pregnant is so hard?

All too often patients, in some groups as many as 30% of women, are told that they have fibroids that may be contributing to their infertility. Fibroids or leiomyomata are non malignant smooth muscle tumors of the uterus. They can vary in number, size and location in the uterus including; the outside facing the pelvic cavity (subserosal), the inside facing the uterine cavity (submucosal) and in between inside the uterine wall (intramural). Fortunately, most fibroids have minimal or no effect on fertility and may be ignored.

The subserosal myoma will rarely cause fertility issues. If it were distorting the tubo- ovarian anatomy so that eggs could not get picked up by the fimbria then it can cause infertility. Otherwise, the subserosal fibroid does not cause problems conceiving.

Occasionally, an intramural myoma may obstruct adequate blood flow to the endometrial lining. The likelihood of this being significant increases with the number and size of the fibroids. The more space occupied by the fibroids, the greater the likelihood of intruding on blood vessels traveling to the endometrium. Diminished blood flow to the uterine lining can prevent implantation or increase the risk of miscarriage. Surgery may be recommended when it is feared that the number and size of fibroids is great enough to have such an impact.
However, it is the submucosal myoma, inside the uterine cavity, that can irritate the endometrium and have the greatest effect on the implanting embryo.

To determine if your fertility is being hindered by these growths you may have a hydrosonogram. A hydrosonogram is a procedure where your doctor or a radiologist injects water through your cervix while performing a transvaginal ultrasound of your uterus. On the ultrasound, the water shows up as black against a white endometrial border. A defect in the smooth edges of the uterine cavity caused by an endometrial polyp or fibroid may be easily seen.

Submucosal as well as intramural myomata can also cause abnormal vaginal bleeding and occasionally cramping. Intramural myomata will usually cause heavy but regular menses that can create fairly severe anemias. Submucosal myomata can cause bleeding throughout the cycle.

Though these submucosal fibroids are almost always benign they need to be removed to allow implantation. A submucosal myoma may be removed by hysteroscopy through cutting, chopping or vaporizing the tissue. A hysteroscopy is performed vaginally, while a patient is asleep under anesthesia. A scope is placed through the cervix into the uterus in order to look inside the uterine cavity. This procedure can be performed as an outpatient in an ambulatory or office based surgery unit. The risk of bleeding, infection or injury to the uterus or pelvic organs is small.

Resection of the submucosal myoma can be difficult especially when the fibroid is large and can sometimes take longer than is safe to be performed in a single procedure. It is not uncommon that when the fibroid is large, it will take multiple procedures in order to remove the fibroid in its entirety. It will be necessary to repeat the hydrosonogram after the fibroid resection to make sure the cavity is satisfactory for implantation.

The good news is, when no other causes of infertility are found, removal of a submucosal fibroid is often successful in allowing conception to occur naturally or at least with assisted reproduction.