First live birth before surgical verification of endometriosis - a nationwide register study of 18 324 women

Authors: Tuominen A, Saavalainen L, Niinimäki M, Gissler M, But A, Härkki P, Heikinheimo O.

Publication: Human Reproduction 2023 Aug 1;38(8):1520-1528.


Endometriosis is commonly associated with pain, reduced fertility, and delayed diagnosis. While endometriosis is commonly associated with pelvic pain, many women may also be asymptomatic and thus unaware of their endometriosis. Therefore, women without painful symptoms may also have reduced fertility. Painful symptoms of endometriosis are thought to be associated with the location of the endometriotic lesions and involvement of local nerves. The association between endometriosis, infertility, and the influence of lesion location remains poorly understood. Therefore, the authors investigated how endometriosis affects fertility of people including before a formal diagnosis was made. In this study, health records collected from 1998 to 2012 of 35,793 women without endometriosis (control group) and 18,324 of women with endometriosis (cases) were analyzed. Cases were further subdivided into four groups based on the location of their endometriotic lesions: ovarian (n = 6,384), peritoneal (n = 5,789), deep (n = 1,267), and other (including combined types, n = 4,884). The main outcome measures were the numbers of live births, age at the first delivery, and whether the type of endometriosis affected the number of live births.

Key findings:

In this study, the mean time from an initial appointment to receiving a surgical diagnosis of endometriosis was 15.2 years. The median age at endometriosis diagnosis was 35 years. People with subsequent endometriosis diagnosis, used medical care more often than the control group in the three years leading to surgical diagnosis. Cases, especially people with a subsequent diagnosis of peritoneal endometriosis, were also more often diagnosed with infertility and pain. Even though people with peritoneal endometriosis were more often diagnosed with infertility compared to people with endometriotic lesions in other locations, endometriosis classification had no effect on fertility. Subsequent endometriosis diagnosis was associated with increasing age at first delivery and progressively lower fertility success.

Take home message:

The data presented in this study confirms the profound diagnostic delay for people with endometriosis. Furthermore, results of this study suggest that endometriosis is linked with reduced fertility. However, fertility was unaffected by endometriotic lesion type. The authors acknowledged the limitations of their study by not including information on any potential artificial reproductive treatments used by the participants. Furthermore, the authors did not specifically assess the correlation between painful symptoms and infertility. Nonetheless, the authors highlight the urgent need for providing early diagnosis and effective treatments to patients who are affected by endometriosis.