Pregnancy and Endometriosis

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Endometriosis is often associated with infertility. Infertility does not mean you cannot get pregnant, but rather there is a delay in achieving pregnancy. It is technically defined as not achieving a “clinical pregnancy after 12 months or more of regular unprotected sexual intercourse” (World Health Organization, n.d.). An estimated 30–50% of women with endometriosis are reported to have difficulty with infertility (Macer & Taylor, 2012). In addition, endometriosis does not have to be an “advanced stage” for it to affect fertility (Bloski & Pierson, 2008).

“Current evidence indicates that suppressive medical treatment of endometriosis does not benefit fertility and should not be used for this indication alone. Surgery is probably efficacious for all stages of the disease.”

(Ozkan, Murk, & Arici, 2008)

With infertility being related to endometriosis, it is unbelievable that pregnancy might still be recommended as a treatment for endometriosis. While some may have a temporary relief of symptoms, others can experience an increase. In fact, some “imaging and histopathology studies of endometriotic lesions during pregnancy show that they may grow rapidly during pregnancy” (Leeners & Farquhar, 2019). Pregnancy will not treat or cure endometriosis. Research has stated that “women aiming for pregnancy on the background of endometriosis should not be told that pregnancy may be a strategy for managing symptoms and reducing progression of the disease” (Leeners et al., 2018). This is echoed again by Leeners and Farquhar (2019) who point out that “the decision to have children should not be influenced by any perceived benefit of improving endometriosis but should be made solely on the wish for parenthood.”

While the overall risk is still low, endometriosis has been associated with some difficulties during pregnancy. Zullo et al. (2017) looked at 24 studies involving almost 2 million women with endometriosis to consider the possible effects of endometriosis during pregnancy . They found that “women with endometriosis have a statistically significantly higher risk of preterm birth, miscarriage, placenta previa, small for gestational age infants, and cesarean delivery” compared to healthy controls (Zullo et al., 2017). Zullo et al. (2017) did not find any significant association with gestational hypertension and preeclampsia with endometriosis; however, adenomyosis has been found to have some correlation with pregnancy-induced hypertension and preeclampsia (Porpora et al., 2020). Adenomyosis has been found to result in a higher likelihood of preterm birth, small for gestational age, and pre-eclampsia (Razavi et al., 2019). Adenomyosis and endometriosis frequently coexist, so it can be hard to determine how much is one or the other causing these effects (Choi et al., 2017).

On a positive note, Porpora et al. (2020) noted that “no difference in fetal outcome was found” and concluded that “endometriosis does not seem to influence fetal well-being”. This was also found by Uccella et al. (2019), stating that “neonatal outcomes are unaffected by the presence of the disease”. Again, a normal pregnancy is still highly possible.


  • Leone Roberti Maggiore, U., Ferrero, S., Mangili, G., Bergamini, A., Inversetti, A., Giorgione, V., … & Candiani, M. (2016). A systematic review on endometriosis during pregnancy: diagnosis, misdiagnosis, complications and outcomes. Human reproduction update22(1), 70-103. Retreived from

“The complications of endometriosis during pregnancy represent the second main issue of this systematic review. These events are rare but represent life-threating conditions that require, in most of the cases, surgical operations to be managed. Acute complications of pre-existing endometriosis may be explained by three different pathogenic mechanisms: endometriosis-related chronic inflammation that makes tissues and vessels more friable (Rossman et al., 1983), adhesions which may cause increasing traction on surrounding structures when the uterus is enlarging (Manresa et al., 2014) and intrusion of decidualized endometriotic tissue into the vessel wall and structures that can increase backpressure, predisposing to tissue rupture (O’Leary, 2006). A total of 76 cases of endometriosis complications during pregnancy have been reported; SH (n = 20), bowel perforation (n = 16) and rupture of endometriomas (n = 14) are the commonest events. Despite the clinical relevance of acute complications during pregnancy leading to potentially life-threating situations for both the mother and the fetus, the rarity of such conditions, as reported in literature, should be underlined. It is also likely that the frequency of these events is underestimated because of unreported cases, giving rise to the need for large observational studies to assess the true incidence of these complications. Due to the unpredictability of these complications, no specific recommendation for additional interventions to the routine monitoring of pregnancy of women with known history of endometriosis is advisable. ”

  • Lazzeri, L., Exacoustos, C., Lariola, I., De Felice, G., & Zupi, E. (2016). OP34. 08: Complications during pregnancy and delivery in women with untreated rectovaginal deep endometriosis. Ultrasound in Obstetrics & Gynecology48, 166-166. Retrieved from

“Women with incompletely removed posterior DIE showed high complications rate during pregnancy and delivery. In particular the presence of posterior DIE is related to a high incidence of preterm delivery, placenta previa and also to delivery complications requiring often high surgical specialist treatment.”

  • Kyozuka, H., Nishigori, H., Murata, T., Fukuda, T., Yamaguchi, A., Kanno, A., … & Yasumura, S. (2020). Effect of Prepregnancy Anti-Inflammatory Diet on Pregnant Women with Endometriosis: The Japan Environment and Children’s Study. Retrieved from

“Increased risk of preterm birth (PTB) in endometriosis is thought to be brought by chronic inflammatory conditions….”

“Results: Of the 9,186 pregnant women in the JECS, 4,119 (44.8%) had obstetrical complications; 330 participants reported a diagnosis of endometriosis before pregnancy, and these women were at higher risk for complications of pregnancy than those without a history of endometriosis (odds ratio (OR) = 1.50; 95% confidence interval (CI) 1.20 to 1.87). Logistic regression analyses showed that the adjusted OR for obstetrical complications of pregnant women who conceived naturally and had a history of endometriosis was 1.45 (CI 1.11 to 1.90). Among pregnant women with endometriosis, the ORs of preterm premature rupture of the membranes (PROM) and placenta previa were significantly higher compared with women never diagnosed with endometriosis who conceived naturally or conceived after infertility treatment, except for ART therapy (OR 2.14, CI 1.03–4.45 and OR 3.37, CI 1.32–8.65). Conclusions: This study showed that endometriosis significantly increased the incidence of preterm PROM and placenta previa after adjusting for confounding of the data by ART therapy.”

“Among 733 pregnancies included in the study, 566 deliveries were recorded (77.2%), of which 535 were singleton (72.9% of pregnancies) and 31 twins (4.2%). SGA was observed in 81 of 535 (15.1%) singleton pregnancies and in 9 of 31 (29%) twin pregnancies. PT occurred in 53 of 535 (9.9%) singleton pregnancies and in 19 of 31 (61.2%) twin pregnancies. The number of singleton and multiple pregnancies complicated by placenta previa were, respectively, 9 of 535 (1.7%) and 0 of 31. The independent factor found to relate to SGA was the absence of endometriomas; conception with the use of assisted reproductive technologies (ART) only tended toward statistical significance. Independent factors found to increase risk of PT were conception with the use of ART, body mass index >30 kg/m 2, and surgery of deep endometriosis infiltrating the rectum and the bladder. Independent factors associated with placenta previa were conception with the use of ART and history of stage III or IV endometriosis. Conclusions: The risk of SGA and PT is increased in women with a history of surgery for endometriosis, and a high rate of conception with the use of ART may jeopardize outcomes.”


Bloski, T., & Pierson, R. (2008). Endometriosis and chronic pelvic pain: unraveling the mystery behind this complex condition. Nursing for women’s health12(5), 382-395. doi: 10.1111/j.1751-486X.2008.00362.x

Choi, E. J., Cho, S. B., Lee, S. R., Lim, Y. M., Jeong, K., Moon, H. S., & Chung, H. (2017). Comorbidity of gynecological and non-gynecological diseases with adenomyosis and endometriosis. Obstetrics & gynecology science60(6), 579. Retrieved from

Leeners, B., Damaso, F., Ochsenbein-Kölble, N., & Farquhar, C. (2018). The effect of pregnancy on endometriosis—facts or fiction?. Human reproduction update24(3), 290-299. Retrieved from

Leeners, B., & Farquhar, C. M. (2019). Benefits of pregnancy on endometriosis: can we dispel the myths?. Fertility and sterility112(2), 226-227. Retrieved from

Macer, M. L., & Taylor, H. S. (2012). Endometriosis and infertility: a review of the pathogenesis and treatment of endometriosis-associated infertility. Obstetrics and Gynecology Clinics39(4), 535-549. Retrieved from

Ozkan, S., Murk, W., & Arici, A. (2008). Endometriosis and infertility: epidemiology and evidence‐based treatments. Annals of the New York Academy of Sciences, 1127(1), 92-100. DOI: 10.1196/annals.1434.007

Porpora, M. G., Tomao, F., Ticino, A., Piacenti, I., Scaramuzzino, S., Simonetti, S., … & Benedetti Panici, P. (2020). Endometriosis and pregnancy: a single institution experience. International journal of environmental research and public health17(2), 401. Retrieved from

Razavi, M., Maleki‐Hajiagha, A., Sepidarkish, M., Rouholamin, S., Almasi‐Hashiani, A., & Rezaeinejad, M. (2019). Systematic review and meta‐analysis of adverse pregnancy outcomes after uterine adenomyosis. International Journal of Gynecology & Obstetrics145(2), 149-157. Retrieved from

Uccella, S., Manzoni, P., Cromi, A., Marconi, N., Gisone, B., Miraglia, A., … & Ghezzi, F. (2019). Pregnancy after endometriosis: maternal and neonatal outcomes according to the location of the disease. American journal of perinatology, 36(S 02), S91-S98. DOI: 10.1055/s-0039-1692130

World Health Organization. (n.d.). Infertility definitions and terminology. Retrieved from

Zullo, F., Spagnolo, E., Saccone, G., Acunzo, M., Xodo, S., Ceccaroni, M., & Berghella, V. (2017). Endometriosis and obstetrics complications: a systematic review and meta-analysis. Fertility and sterility108(4), 667-672. Retrieved from