One of the pioneers of uterine artery embolization, Bruce McLucas, tells Interventional News: “We used to say that we should not perform uterine artery embolization in patients who might want to have children. However, if you look at the groups around the world, including ours, who have done the procedure in younger women, the opposite holds true. Women are happy with the results and there is no risk of having to have four major surgeries if you want to have two children (two myomectomies and two caesarean sections).” McLucas clarifies that women who have had uterine artery embolizations and then gone on to have children are an understudied group
McLucas et al published data in Minimally Invasive Therapy (2012) showing that of 44 women who stated a desire for fertility under the age of 40, who were embolized between 1996 and 2010, 22 reported 28 pregnancies. Of these pregnancies, 20 live births, three miscarriages, and three instances of premature labour were reported. Seventeen of these pregnancies were delivered by caesarean section and six pregnancies were vaginal deliveries. At the time of publication, one woman was still pregnant.
No perfusion problems, either during pregnancy or labour, were reported. From these results, the authors concluded that the course of pregnancy and delivery was largely normal after embolization with few cases of premature labour and miscarriages reported. Forty-eight per cent of women who were under 40 and desired pregnancies were able to have successful term pregnancies.
What is the new evidence that could refute the idea that uterine artery embolization is not indicated in younger women?
To begin with, we need to see this problem as reverse engineering. We know that women get pregnant after uterine embolization, and that has been reported in nearly every country where it is being performed. The data above show that close to 50% of patients under the age of 40 who wanted fertility had had full-term pregnancy after embolization. That is the same figure as myomectomy —which is the only procedure you can really compare it to as they are both uterine-sparing and they both allow the option of pregnancy.
There are disadvantages of embolization—the fibroids are not completely taken out—they are shrunk so there is a higher chance of the same things that would make pregnancy with fibroids (without embolization) a problem. These are problems such as malpresentation of the baby, the possibility of an obstructed birth canal and a small chance of post-partum haemorrhage. These have to be weighed against the disadvantages of myomectomy. (The biggest disadvantage of myomectomy is the chance of recurrence.)
We have to make it clear to patients that no one would advise a patient to undergo a myomectomy or an embolization without symptomatic fibroids. Patients would not be offered these procedures just to improve fertility.
With regards to patients becoming pregnant after a myomectomy, there is a “golden period” after six to 12 months of post-myomectomy, where it is strongly suggested that they try to get pregnant. The reason for this is because after 12 months the risk of recurrence returns. In the case of younger women who might need a myomectomy, they are often not ready to have a family. In this case, I mean women who are in their 20s who may not have a partner or are not in a settled relationship.
The simple fact is that there are a lot of women who are suffering from fibroids who are not in a position to make use of that golden period. Therefore embolization fixes the problem once and for all, as it means the woman can wait to start their family. Women desiring fertility should be apprised of potential risks of uterine artery embolization, including the small chance of premature ovarian failure (10/1000), and even a lower possibility of hysterectomy (5/1000) because of infection after the procedure.
Longer-term trials suggest that fibroid recurrence is also a problem with embolization. Is this case?
We have not observed this. We did our first embolization in 1994 in Los Angeles, USA, and we found that in the majority of patients in whom the procedure fails, this occurs in the first year. We have not found, for example, that the younger patients are any more likely to have a procedural failure compared to the older women. I have done a number of repeat embolizations mostly where the patient is sent to me where the uterine arteries were not completely embolized. We have performed uterine artery embolization in about 5,000 patients, so we have good follow-up on these patients. There is no perfect way of dealing with fibroids but embolization is the least imperfect of the two options, and especially so in the younger patients.
What other evidence has been gathered?
The other important data to note is the comparison of the level of the anti-müllerian hormone (AMH) levels before and after embolization. One of the criticisms levelled at embolization is that it lowers the levels of ovarian reserve, and we just have not seen it. The first study we conducted just looked at women more than six months after embolization under the age of 40 and we found the anti-müllerian hormone levels were well within normal limits.
We have a second study that is underway now, looking at hormone levels before and after embolization. This was a criticism of our early studies that we only monitored the levels after embolization. However, the before and after data we are getting now shows that there is not a drop-off after embolization in anti-müllerian hormone levels.
I cannot say people around the world will have the same experience that we have had. However, interventionalists and patients can have a balanced discussion before they are signed up for a myomectomy. There are ways of doing myomectomies that are less invasive, robotic surgeries for example, but recurrence is a problem, unless embolization is used. I think this can be offered to patients without fearing that you will get anything else but a fertility-enhancing result.