At Fertility Centers of Illinois, we believe in staying current on recent literature and applying that knowledge to better care for our patients. We enjoy sharing that information with fellow physicians to help keep you informed on recent advances regarding infertility therapies. The Information letter from Fertility Center of Illinois this month deals with fibroids and infertility.
While many women conceive with leiomyomata and even go on to deliver vaginally at term, the likelihood of successful pregnancy is clearly reduced overall. The probabilities lie in the size and position of the fibroids. Most obviously, the biggest culprit to prevent implantation is the submucous myoma, and virtually any size can cause problems if in the fundal area. Also obvious are the intramural or transmural myomata, which extend into the cavity and have a submucous component.
Studies have been done to show that certain RNAs associated with implantation are reduced or absent with submucous myomata. The simple physical presence, as well as the attendant inflammation and abnormal endothelial surface, can explain the negative effects.
The next type of myoma that is problematic is one that does not have a submucous component but distorts the cavity, which may have more implications for the maintenance of pregnancy than conceiving. This type can also play a role in premature labor, obstructed labor, and complications at delivery.
Less obvious and not an absolute factor are subserosal fibroids. Strictly speaking, if they do not interfere with tubal function and are clearly away from the cavity, they can be left alone. But normal tubal function may be impaired by strategically placed subserosal myomata, which may not be obvious.
Lastly, the intramural myoma that has no submucous component and does not distort the cavity may be the most difficult to assess its effects. There are several studies that document the proximity of intramural myomata larger than 4-5 cm to the cavity to result in reduced pregnancy rates from IVF.
It is not a jump to assume that natural conception may be affected in a similar manner. It seems that conception may occur due to the good fortune of an embryo implanting on the wall opposite the myoma’s influence; thus, overall pregnancy rates are beholden to chance (which no one likes) as are the rates of normal progress of the gestation. There is good evidence that myomata may shrink, grow, or stay the same during pregnancy; even one that has not interfered with conception may degenerate and jeopardize the pregnancy. The inflammation of an ischemic fibroid can present as an acute abdomen and even a pelvic infection.
The diagnosis of fibroids can be made by plain pelvic ultrasounds, the vaginal probe usually being more reliable in determining position, but enhancing the visualization by a saline infusion sonogram or hysterosonogram, will characterize size and position better. Hysterosalpingography is not as helpful, and more elaborate methodologies like CT or MRI would usually be redundant, but often useful in certain cases.
Surgery is the mainstay of treatment, and hysteroscopic and laparoscopic techniques are widely used and are shown to have excellent results, with the least damage to normal uterine tissue. However, open myomectomy is often necessary with large or transmural myomata. The need for future Caesarean sections will depend on the entry into the cavity and integrity of the wall. The medical management of fibroids seems to be most efficient for the intramural and transmural myomata; using GnRH analogs, both agonists and antagonists have been shown to reduce the volume, but the process tends to be reversible once therapy is stopped. Ulipristal and mifepristone are progesterone modulators that have shown promise in reducing myoma size, but again without certain lasting effects. Medical pretreatment prior to surgery has been shown to be quite useful in reducing blood loss and normal tissue disruption.
While at Michael Reese Hospital in the mid-80s, I published a paper demonstrating the efficacy of leuprolide acetate in the medical management of myomata. However, this was usually prior to surgery or for long term medical management. Thus, the decision to treat fibroids may be pre-emptive, or only after a time of infertility or a pregnancy loss. The sooner the better, for sure.