Arch Gynecol Obstet (2008) 277:95–98 DOI 10.1007/s00404-007-0405-6 123 CASE REPORT Pierre-Robin syndrome: a case report Andreea Chiriac · Anja Dawson · Martin Krapp · Roland Axt-Fliedner Received: 3 June 2007 / Accepted: 5 June 2007 / Published online: 6 July 2007  Springer-Verlag 2007 Abstract We report a case of a fetus diagnosed with micro-retrognathism at routine ultrasound examination in the 22nd week of gestation. The diagnosis of Pierre-Robin syndrome was made postnatally. The possible diVerential diagnoses and the main complications of retrognathism are reviewed. Keywords Fetal retrognathism · Fetal micrognathism · Pierre-Robin syndrome Introduction Abnormal size and position of the chin (micro-retrognath- ism) are part of features in numerous syndromes. Micro- gnathia is a facial malformation characterized by mandibular hypoplasia. Retrognathia is deWned by the retrusion of the mandible. Both anomalies are common Wndings in many chromosome aberrations and dysmorphic syndromes. Until present, over 300 syndromes are described in which micrognathism is part of the characteris- tic sonographic Wndings and almost 50 for retrognathia (OMIM). Both anomalies can be diagnosed sonographi- cally from the early second trimester onwards. When micrognathia is diagnosed, fetal karyotyping should be oVered in order to rule out chromosomal abnormalities. Those fetuses diagnosed with micrognathia should be delivered in a hospital with neonatology department, because these infants may present with severe respiratory distress, and diYcult orotracheal intubation and also feed- ing problems. Micro-retrognathism in newborns has a good prognosis when adequate reconstructive surgery of the mandible and associated oral anomalies is performed. We report a case of severe fetal retrognathia and micro- gnathia diagnosed sonographically in the 22nd week of ges- tation. The patient, 24-year-old, G2P0, was referred to our clinic for targeted ultrasound. Both parents originated from Turkey, and consanguinity was excluded. The family his- tory regarding congenital anomalies or genetic syndromes was negative. The ultrasound examination performed at 21 + 5 gestational weeks showed severe micro-retrognath- ism without further sonographical abnormalities. The suspi- cion of Pierre-Robin sequence was raised antenatally and the parents were counselled by an interdisciplinary approach (obstetrician, neonatologist, genetician and oral, and maxillofacial surgeon). In order to exclude any chro- mosomal defect, fetal blood sampling was performed. The karyotype revealed a pericentric inversion on chromosome 9 (46, XY, inv(9)(p11q13)). This pericentric inversion was a familial normal variant, the father having the same modi- Wcation. The patient wasn’t very cooperating, and the next ultra- sound examination was performed in the 31 + 3 gestational weeks. Beside the mentioned facial dysmorphism it was noticed polyhydramnion as a consequence of impaired fetal deglutition. The estimated fetal weight was below the 3rd percentile, with normal Doppler indices on fetal vessels but with increased resistance and pulsatlity indices on both uterine arteries, with unilateral notching. The patient delivered vaginally in the 36 + 5 gestational weeks due to premature rupture of membrane and a male infant was born. The birth parameters were: 1840 g (< 3rd A. Chiriac (&) · A. Dawson · M. Krapp · R. Axt-Fliedner Department of Obstetrics and Prenatal Medicine, University Clinic of Obstetrics and Gynecology, University Hospital Lübeck, Ratzeburger Allee 160, Lübeck 23538, Germany e-mail: chiriandra@yahoo.com