Schwartz ASK, et al. - The prevalence of miscarriage was compared among women with endometriosis (WwE) vs. disease-free control women (CW). Findings demonstrated an association of mild endometriosis, as in superficial lesions, with a great extent of inflammatory disorder, which in turn, possibly result in defective folliculogenesis, fertilization, and/or implantation, presenting as increased risk of miscarriage.

Methods

• This cross-sectional analysis nested in a retrospective observational study (n = 940) was conducted at the hospitals and associated private practices.
• Study participants included previously pregnant women (n = 268) within reproductive age in matched pairs.
• Surgical reports and self-administered questionnaires were analyzed retrospectively.
• Main outcome measures included rate of miscarriage, subanalysis for fertility status (≤12 vs. >12 months' time to conception), endometriosis stages (revised American Society of Reproductive Medicine classification [rASRM] I/II vs. III/IV) and phenotypic localizations (superficial peritoneal, ovarian, and deep infiltrating endometriosis).

Results

• Findings demonstrated a higher miscarriage rate in WwE (35.8% [95% confidence interval 29.6%–42.0%]) vs CW (22.0% [16.7%–27.0%]); adjusted incidence risk ratio of 1.97 (95% CI 1.41–2.75).
• Researchers observed that this remained significant in subfertile WwE (50.0% [40.7%–59.4%]) vs. CW (25.8% [8.5%–41.2%]) but not in fertile WwE (24.5% [16.3%–31.6%]) vs. CW (21.5% [15.9%–26.8%]).
• Data also reported that the miscarriage rate was higher in women with milder forms (rASRM I/II 42.1% [32.6%–51.4%] vs. rASRM III/IV 30.8% [22.6%–38.7%], compared with 22.0% [16.7%–27.0%] in CW), and in women with superficial peritoneal endometriosis (42.0% [32.0%–53.9%]) compared with ovarian endometriosis (28.6% [17.7%–38.7%]) and deep infiltrating endometriosis (33.9% [21.2%–46.0%]) compared with CW (22.0% [16.7%–27.0%]).