Why is age a major determinant of reproductive outcomes after myomectomy in subfertile women?

Dear Sir,

I am grateful to Pundir et al. (2014) whose recent article I read with great interest. The authors present new useful data on fertility after abdominal surgery for uterine fibroids. The good news is that abdominal myomectomy in subfertile women is followed by pregnancies and live births even in case of large fibroid uteri. The bad, albeit useful, news is that myomectomy alone might not be an adequate intervention to increase the fertility potential of older subfertile women. This is consistent with our previous finding that age is a major determinant of pregnancy after laparoscopic or abdominal myomectomy for fibroids not distorting the uterine cavity (adjusted odds ratio: 0.65; 95% confidence interval: 0.48–0.88) (Campo et al. 2003). The work by Pundir and collaborators has the merit of focussing on a specific subset of women with large fibroid uteri. As a specialist in reproductive medicine with interest in the uterine factor, I found their results relevant to our field and potentially supporting in specific clinical situations. The complex intersection between fibroids, age and fertility, is a challenge in modern reproductive medicine, and an individualized approach is often the only option (Gambadauro 2012).

By reading this paper, I felt the need for a brief digression on the pathophysiology of the association between myomectomy's fertility outcomes and age, hoping that it would be constructive and propaedeutic to further investigations in this field.

Age-related fertility decline is predominantly linked to the oocytes. Since age is also related to fibroids, then oocyte quality is an important confounding factor in most studies on fertility after myomectomy. Interestingly, no significant differences are seen in the outcomes of in vitro fertilisation among egg-recipients with variable number and size of fibroids, with a previous myomectomy, or without fibroids in their medical history (Horcajadas et al. 2008).

Could fibroids, in some cases, also be one manifestation of an ageing or dysfunctional uterus? The poorer endometrial receptivity associated with submucous fibroids is not restricted to the overlying mucosa but is global (Rackow and Taylor 2010). For deeper fibroids, a broader disruption of the myometrial junctional zone has also been suggested (Ciavattini et al. 2013). Adenomyosis is more common in older women and arguably interferes with female fertility (Campo et al. 2012).

Following surgery, ageing could be related with variable healing patterns and therefore interfere with a functional restitutio ad integrum. Intrauterine adhesions, for instance, are often overlooked (Gambadauro et al. 2012). However, systematic hysteroscopy after abdominal myomectomy has been shown to detect adhesions in 50% of women with an average age of 39.8 years, irrespective of factors such as cavity opening or specimen weight (Conforti et al. 2014).

Infertility is often multifactorial but we might tend to classify patients depending on the etiology that we consider to be dominant. A focus on the fibroids is reasonable when evaluating a subfertile woman with no other plausible infertility cause, particularly when those are submucous or, as in the case of this study, large and multiple. Besides, myomectomy might also be justified by specific symptoms such as abnormal bleeding. However, not all women benefit from surgery in terms of fertility, particularly if older. In my opinion, a wise warning can be found between the lines of the article: are we sometimes staring at the finger pointing to the moon?

Declaration of interest: The author reports no declarations of interest. The author alone is responsible for the content and writing of the paper.