Prenatal diagnosis of Pierre Robin Sequence: accuracy and ability to predict phenotype and functional severity.

OBJECTIVE: To assess the outcome of fetuses who had sonographic features suggestive of Pierre Robin Sequence (PRS). METHOD: All prenatal ultrasounds that mentioned 'posterior cleft palate', or 'micro or retrognathia' or 'PRS' over 13 and 20 years, respectively, at two obstetrical centers were reviewed. Medical records for children with isolated PRS monitored over 20 years at a PRS referral center for prenatal anomalies and the severity of neonatal feeding and respiratory functional disorders were utilized for comparison. RESULTS: From a prenatal ultrasound database of 166 000 cases, 157 had one or more of the sonographic signs suggestive of PRS and had follow-up available. Of them, 33 (21%) had confirmed PRS, 9 (6%) were normal and 115 (73%) had chromosomal aberrations, associated malformations or neurological anomalies. Visualization of a posterior cleft palate in addition to retro-micrognathia had a positive predictive value of 100% for PRS. The distribution of functional severity grades was similar in cases suspected prenatally as in 238 cases of PRS followed in the referral center in Necker Hospital. CONCLUSION: Only a minority of cases of fetal retrognathia have complete PRS; the majority have other severe conditions. Prenatal prediction of functional severity of isolated PRS is not possible.