Increased risk of obstetric complications in patients with adenomyosis: A narrative literature review

Abstract

Background Reproductive‐age women occasionally face the pathological condition of adenomyosis, which is often concurrent with endometriosis. It is believed that endometriosis and adenomyosis increases the risk of obstetric complications. Although new insights into the mechanism of obstetric complications due to endometriosis are emerging, there is little information on the etiology of adverse pregnancy outcomes in pregnant women with adenomyosis. Methods We performed a literature review focusing on the pathophysiological pathways of obstetric complications in women with adenomyosis using currently available basic and clinical studies. We used the internet search engines PubMed and Google Scholar to search for studies published between January 2000 and June 2021. We carefully read pertinent sections within each document to ensure relevancy. Main findings The prevalence of adverse pregnancy outcomes in women with adenomyosis is increased after adjusting for conceiving by assisted reproductive technology. Thus, adenomyosis emerges as a relevant factor associated with several obstetric complications such as preterm birth, preterm premature rupture of membranes, placental abruption, small for gestational age/fetal growth restriction, and preeclampsia. Conclusion It is plausible that the impact of adenomyosis on pregnancy outcomes is not always the same; rather it is dependent on the degree of uterine involvement and subtypes.

Adenomyosis in Pregnancy—Should It Be Managed in High-Risk Obstetric Units?

“…For this reason, some researchers tried to summarize the current evidence on the risks associated with adenomyosis during pregnancy in several literature reviews, such as the ones carried out by Harada et al [ 27 ], Buggio et al [ 28 ], and Wendel et al [ 29 ]. However, these papers just reviewed the literature and speculated about the potential mechanisms that explain why adenomyosis can produce poorer obstetrical outcomes [ 27 ] and highlighted several methodological drawbacks of the studies reported, such as poor design, small sample size, high qualitative heterogeneity, potential misclassification bias, and co-morbid conditions; this prevents drawing definitive conclusions on the strength of the observed associations and on the magnitude of the treatment effects [ 28 ]. Another common problem in the recruitment of patients with adenomyosis lies in the confirmation of the diagnosis.…”

“…The underlying mechanisms through which adenomyosis causes poor obstetrical outcomes have not yet been elucidated. There are some proposed explanations such as immunological changes, inflammation, increased uterine pressure, increased prostaglandin expression, increased myometrial wall thickness, and abnormal trophoblastic invasion and placentation due to an abnormal myometrial–endometrial junctional zone [ 27 ]. For example, a eutopic endometrium in women with adenomyosis shows aberrant immunological changes contributing to implantation failure, which could explain the high abortion rate [ 27 ].…”

“…There are some proposed explanations such as immunological changes, inflammation, increased uterine pressure, increased prostaglandin expression, increased myometrial wall thickness, and abnormal trophoblastic invasion and placentation due to an abnormal myometrial–endometrial junctional zone [ 27 ]. For example, a eutopic endometrium in women with adenomyosis shows aberrant immunological changes contributing to implantation failure, which could explain the high abortion rate [ 27 ]. Some studies showed that the rate of uterine infection in patients with diffuse-type adenomyosis was higher than that in patients with focal-type adenomyosis [ 31 , 32 ].…”

“…The pathogenic processes associated with microbial or sterile inflammations can induce a common pathway resulting in preterm birth. Furthermore, some studies reported an increased intrauterine pressure in patients with adenomyosis, which may also lead to preterm labor and birth [ 27 ]. A recent study assessing myometrial thickness by ultrasonography showed that the uterine wall was thicker and less stretched during the second trimester of pregnancy in women who had a preterm delivery [ 34 ].…”

Glycolysis and Heavy Menstrual Bleeding

“…Thus, in both cases, the downregulation of glycolytic enzymes can be conceived as evidence of decidualization defect, which would also include the view of endometrial glycolysis defect as primary endometrial disorder originating from the endometrial cell functions, and not as a secondary effect from physically measured conditions such as adenomyosis. On the other hand, adenomyosis have also been associated with higher occurrence of preeclampsia [8]-making it, again, more difficult to evaluate the causality. In any case, collectively, the evidence points out that a well-balanced glycolytic drive is essential for healthy endometrial function.…”