Obstetrical complications of endometriosis, particularly deep endometriosis. 
Over the past few years, a new topic in the field of endometriosis has emerged: the potential impact of the disease on pregnancy outcomes.  This review aims to summarize in detail the available evidence on the relationship between endometriosis, particularly deep endometriosis (DE), and obstetrical outcomes.  Acute complications of DE, such as spontaneous hemoperitoneum, bowel perforation, and uterine rupture, may occur during pregnancy.  Although these events represent life-threatening conditions, they are rare and unpredictable.  Therefore, the current literature does not support any kind of prophylactic surgery before pregnancy to prevent such complications.  Results on the impact of DE on obstetrical outcomes are debatable and characterized by several limitations, including small sample size, lack of adjustment for confounders, lack of adequate control subjects, and other methodologic flaws.  For these reasons, it is not possible to draw conclusions on this topic.  The strongest evidence shows that DE is associated with higher rates of placenta previa; for other obstetrical outcomes, such as miscarriage, intrauterine growth restriction, preterm birth and hypertensive disorders, results are controversial.  Although it is unlikely that surgery of DE may modify the impact of the disease on the course of pregnancy, no study has yet investigated this issue.