This 26-year-old G₂P₁ patient was referred for a problem of infertility. An endometriosis stage IV was diagnosed by laparoscopy. She was treated by intra-muscular injection of superactive analog of LHRH. She became pregnant after the third injection.
When she underwent routine ultrasound at 12^th weeks, an abnormal sonolucency of the neck (6 mm) was noticed without any other structural abnormalities. A transcervical chorionic villus sampling revealed a normal 46 XX chromosome pattern.

Follow-up ultrasound examinations were performed at 21, 31, 32, 33 and 34 weeks. and the following features were found:

Shortening of all long bones (humerus, radius, ulna, femur, tibia, fibula). The measurements were under 5^th percentile at 21 weeks and after, but the growth was parallel with normal curves (fig 1: femur: 51mm = 32 weeks).

• Fetal profile (32 weeks)

• One kidney

• and the other one

• the bladder remained as on the image

• an enlarged umbilical portion of portal vein

• There was an abnormal angulation between a wide thumb and radius.

• growth retardation was present after 31 weeks (abdominal and head perimeter below the 10^th percentile)

• moderate hydramnios

The patient was followed to term. An amniocentesis at 32 weeks confirmed the earlier diagnosis of normal karyotype.
Spontaneous delivery occurred at 35 weeks. The birth weight was 2040 grams, size:41 cm, HC 28.5 cm.
Post-natal evaluation confirmed facial dysmorphology and abnormality of hands with broad thumbs and radial angulation

The findings thus included:

• Shortening of all long bones (humerus, radius, ulna, femur, tibia, fibula). The measurements were under the 5^th percentile at 21 weeks and after, but the growth was parallel to normal curves (fig: femur: 51 mm, 32 weeks), with femur/foot ratio: 0.8.
• Growth retardation was present after 31 weeks (abdominal and head perimeter under the 10^th percentile)
• Moderate hydramnios (amniotic fluid index >95^th percentile)
• An abnormal profile with retrognathism.(fig, fetal profile 32 weeks)
• Mild right pyelectasy (7.5mm) (fig. abdominal cross- section, 31 weeks) with abnormal hyperechoic kidney cortex suggesting a right renal dysplasia
• An abnormal left kidney, which appeared very long and unusual in shape with abnormal cortico-medullar differentiation (fig.).
• The bladder was full during all the examinations, so we suspected an abnormality of micturition. (fig. full bladder 34 weeks).
• An enlarged umbilical portion of portal vein (fig.).
• The most important finding that pointed to the diagnosis was the abnormal angulation between thumb and radius (fig.: forearm and thumb lateral view 34^th weeks).

These findings are most consistent with the Rubinstein-Taybi syndrome also called Broad Thumb-Hallux syndrome.