Clinical implication
Several evidences suggest that endometriosis is associated with the risk of several chronic diseases such as asthma, allergies, and coronary heart disease (CHD). Although the aetiology of endometriosis remains poorly understood, the levels of inflammation-related factors, such as interleukin (IL)-1 and IL-6 and tumour necrosis factor (TNF)-alpha, have been reported to increase in the peritoneal fluid and peripheral blood of women with endometriosis.25,26 These reports suggest that endometriosis is associated with local and systemic inflammations. Because chronic inflammation plays key roles in the pathogenesis of allergy-related conditions and CHD, endometriosis may increase the risk of these conditions. Although endometriosis is related to fertility and chronic diseases, clinical importance also focuses on association with adverse obstetric outcomes. In a systematic review and meta-analysis, Zullo et al. reported that women with endometriosis have higher risk of several adverse obstetric complications such as PTB.6 Using preliminary JECS dataset, Harada et al. already reported that endometriosis significantly increased the incidence of PTB-related condition such as preterm premature rupture of the membrane.27 Pro-inflammatory cytokines, such as IL and TNF, produce prostaglandin (PG) and matrix-degrading enzymes. PG stimulates uterine contractions, whereas degradation of the extracellular matrix leads to preterm rupture of fetal membranes, resulting in PTB. Therefore, anti-inflammatory diet against endometriosis, which is a pro-inflammatory condition, is thought to be plausible for PTB prevention.
Recently, interest in preconception health has been increasing,28 as preconception is a crucial period for influencing not only pregnancy outcomes but also the long-term health of the mother and her child. Because endometriosis is a chronic health condition, clinical management of women with endometriosis is essential not only for short-term outcomes including successful implantation and pregnancy, but also for promotion of long-term health. The preconception period could be regarded as a ‘window of opportunity’ to promote maternal health because it represents a time when women are most willing to abandon unhealthy habits.29 Until now, preconception care for women with endometriosis was not adequately discussed, considering the need to improve obstetric outcomes and future health. Additionally, preconception diet counselling could assist in providing the motivation to alter food-intake behaviour during pregnancy,30preconception counselling to alter usual diet habit for an anti-inflammatory diet could become a potential management for women with endometriosis to reduce the risk of obstetric complication and promote long-term health.