title: Dichorionic twins discordant for thanatophoric dysplasia managed with selective reduction at 20 weeks' gestation: a case report.
abstract: BACKGROUND
  Thanatophoric dysplasia (TD) is a rare and lethal form of skeletal disorder. A MEDLINE search for 1965-2003 yielded only 3 reports of multiple pregnancies discordant for TD. This is the first case report of selective twin reduction for this diagnosis.
  
  
  METHODS
  A young woman was seen in consultation at 20 weeks' gestation. Ultrasound examination revealed a twin pregnancy, with ultrasound markers consistent with thanatophoric dysplasia, type II, in twin A. A thick dividing membrane and separated placentas were noted. After counseling, the patient opted for selective termination of twin A. Termination was performed by intracardiac injection of potassium chloride. The pregnancy continued uneventfully until 33 weeks, when spontaneous labor resulted in vaginal delivery of a vigorous female infant, and a mummified, macerated fetus.
  
  
  CONCLUSIONS
  Selective termination for discordant lethal anomalies can be safely performed when the presence of the anomalous twin increases the risk of a poor perinatal outcome for the apparently normal cotwin.
authors.affiliation: Division of Maternal-Fetal Medicine, Department of Obstetrics, Gynecology and Reproductive Sciences, University of Texas-Houston Medical School, Houston 77030, USA. alex.c.vidaeff@uth.tmc.edu
authors.forename: Alex C
authors.initials: AC
authors.lastname: Vidaeff
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Lucas
authors.forename: Melissa B
authors.initials: MB
authors.lastname: Strassberg
authors.forename: Keith I
authors.initials: KI
authors.lastname: Spooner
authors.forename: Susan M
authors.initials: SM
authors.lastname: Ramin
mesh_terms: D000328:Adult; D004200:Diseases in Twins / Q000000981:diagnostic imaging* / Q000628:therapy; D005260:Female; D006321:Heart / Q000187:drug effects; D006801:Humans; D007267:Injections; D011189:Potassium Chloride / Q000494:pharmacology; D011247:Pregnancy; D011256:Pregnancy Outcome; D018607:Pregnancy Reduction, Multifetal; D011262:Pregnancy Trimester, Second; D013796:Thanatophoric Dysplasia / Q000000981:diagnostic imaging* / Q000628:therapy; D014429:Twins, Dizygotic; D016216:Ultrasonography, Prenatal
chemical_list: D011189:Potassium Chloride