Pregnancy in women with advanced endometriosis and adenomyosis: possible complications and the role of surgery.

introductionAdvanced endometriosis (stage III-IV, per the revised American Society for Reproductive Medicine (rARSM) classification of endometriosis) is associated with a range of pregnancy-related complications. Despite growing evidence, awareness of these risks remains limited among healthcare providers. Furthermore, the impact of endometriosis surgery prior to conception on pregnancy outcomes remains uncertain. The primary objective of this narrative review is to evaluate whether pre-conception surgery for advanced endometriosis influences early pregnancy, obstetric and neonatal outcomes. In the absence of robust surgical data, we also review outcomes in women with advanced endometriosis irrespective of surgical history, and we provide brief recommendations for pregnancy monitoring and delivery planning in this population.

findingsEvidence on how endometriosis surgery affects the risk of miscarriage is inconsistent, though most studies suggest a slightly increased risk in women with advanced disease, particularly in the presence of adenomyosis. For pre-eclampsia and hypertensive disorders, surgery does not appear to modify the risk and the higher rates seen in women with endometriosis may instead reflect co-excisting adenomyosis or the use of assisted reproductive technologies (ART). The risk of preterm birth is elevated in both surgically and conservatively managed groups, compared to the general population, but no significant difference is evident between the two groups. It remains uncertain whether endometriosis surgery or advanced disease itself increases the risk of delivering a small-for-gestational-age infant. Notably, foetal growth restriction appears to be more strongly associated with adenomyosis than with endometriosis. The risk of placenta praevia is reported to be increased in women with advanced endometriosis, but the impact of surgery remains unclear. Some studies suggest it may reduce the risk, while others report the opposite, possibly due to confounding by disease severity, adenomyosis or use of ART. Data on rarer outcomes-such as stillbirth, placental abruption, uterine rupture, haemoperitoneum, and bowel perforation-remain scarce. Decidualised endometriomas can pose diagnostic challenges during pregnancy, though complications related to ovarian endometriosis in pregnancy appear rare. Finally, medical treatment of advanced endometriosis during pregnancy and the postpartum period is guided mainly by clinical experience and expert opinion, as high-quality evidence is lacking.

conclusionWhile advanced endometriosis is linked to higher risks of pregnancy complications, there is no consistent evidence that pre-conception surgery reduces these risks. Well-designed, multicentre prospective studies are urgently needed to disentangle the roles of surgery, disease severity, adenomyosis, and ART. Meanwhile, individualised, multidisciplinary care remains essential, with careful documentation of endometriosis history and risk-stratified referral to tertiary centres when high-risk features are present.