title: First-trimester diagnosis of cesarean scar ectopic pregnancy.
abstract: Once considered extremely rare, implantation of a pregnancy within the scar of a previous cesarean section is becoming more common. In fact, its incidence is now higher than that of cervical ectopic pregnancies. We identified 5 cases of ectopic pregnancy implanted in a prior cesarean section scar at our institution since 2004. We outline the criteria for the first-trimester sonographic diagnosis of cesarean scar ectopic pregnancy, including a new sign of lower uterine segment ballooning, which has previously not been reported. Clinicians must have a heightened awareness of this serious and potentially fatal pregnancy complication.
authors.affiliation: Department of Obstetrics and Gynecology, Division of Gynecology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA.
authors.forename: Elysia
authors.initials: E
authors.lastname: Moschos
authors.forename: Sreedevi
authors.initials: S
authors.lastname: Sreenarasimhaiah
authors.forename: Diane M
authors.initials: DM
authors.lastname: Twickler
mesh_terms: D000328:Adult; D002585:Cesarean Section / Q000009:adverse effects*; D002921:Cicatrix / Q000000981:diagnostic imaging*; D005260:Female; D020073:Gravidity; D006801:Humans; D010298:Parity; D011247:Pregnancy; D011248:Pregnancy Complications / Q000000981:diagnostic imaging*; D011256:Pregnancy Outcome; D011261:Pregnancy Trimester, First; D011271:Pregnancy, Ectopic / Q000000981:diagnostic imaging* / Q000628:therapy; D016216:Ultrasonography, Prenatal