title: Ultrasound in labor monitoring: how to define the  plane of ischial spines?
authors.forename: E G
authors.initials: EG
authors.lastname: Simon
authors.forename: C J
authors.initials: CJ
authors.lastname: Arthuis
authors.forename: F
authors.initials: F
authors.lastname: Perrotin
mesh_terms: D005260:Female; D006801:Humans; D007512:Ischium / Q000033:anatomy & histology / Q000000981:diagnostic imaging*; D007743:Labor, Obstetric; D011247:Pregnancy; D011631:Pubic Symphysis / Q000000981:diagnostic imaging; D014463:Ultrasonography