Congenital retrognathia, with or without Pierre Robin Sequence (PRS), is a rare anomaly which can be associated with chromosomal abnormalities. Respiratory and feeding consequences can be present at birth. After birth, the diagnosis of retrognathia is based on the clinical examination. Cephalometry can be used to complete the diagnosis. Several authors have proposed the use of objective quantitative ultrasound parameters for the antenatal screening of PRS. In our study, the investigators evaluated fetal cephalometry.

The aim First, the investigators studied the inter- and intra-observer reproducibility of cephalometry. Second, the investigators established reference values for antenatal cephalometry in normal fetuses. Third, the investigators compared the diagnostic performance of cephalometry and the other angles described in the literature for the diagnosis of retrognathia.

Inclusion criteria:

• Pregnant patient (Aged >18years old)
• with one or more fetuses suffering from a microretrognathia
• diagnosed prenatally
• integrated into a Pierre Robin Sequence

Exclusion criteria:

• Uncvertain diagnosis
• Absence of 3D rendering volume

All pregnant patients with one or more fetuses suffering from a microretrognathia, diagnosed prenatally and integrated into a Pierre Robin Sequence

NC