Benaglia L, Reschini M, La Vecchia I, et al. - In this retrospective case series, researchers estimated the frequency of spontaneous hemoperitoneum in pregnancy (SHiP) in women with endometriosis achieving pregnancy with in vitro fertilization (IVF). Participants in the study were 348 women with a history of surgery for endometriosis and women with ovarian endometriomas or deep endometriotic nodules detected at basal transvaginal ultrasound performed prior to the IVF cycle. Overall, 362 pregnancies were involved, among which 238 had a history of previous surgery for endometriosis and 231 had endometriosis detected at the ultrasound. The SHiP is uncommon in the general population of women with endometriosis undergoing IVF. The risk factors for SHiP to disentangle the subgroups of women at greater risk should be better identified by future research.