Skeletal Dysplasias / Dwarfing Conditions
What is a skeletal dysplasia?
Skeletal dysplasias are a complex group of more than 200 disorders that affect fetal bone and cartilage growth and result in short stature or "dwarfism." Skeletal dysplasias affect one in every 4,000 to 5,000 newborns. The condition is generally caused by spontaneous gene mutations or genetic abnormalities. Each type of skeletal dysplasia has a unique range of complications, can be passed through the family, and indicates an increased chance the disorder will occur again in another pregnancy.
How is a diagnosis made?
Skeletal dysplasias may be found by ultrasound during a pregnancy, most often during a routine ultrasound around 20 weeks (five months) of pregnancy. If a skeletal dysplasia is suspected, detailed examinations of the fetal skeleton may be needed. These include a level II ultrasound, 3-D ultrasound or fetal MRI (magnetic resonance imaging). A physician may also recommend genetic testing when a skeletal dysplasia is suspected prior to birth, even without a family history of the disorder.
Will a fetal treatment be required?
There currently is no prenatal treatment option for skeletal dysplasias. However, The Texas Fetal Center team develops a personalized plan of delivery and post-natal care for both mother and baby to ensure a smooth transition for the newborn.
What special considerations should be made for delivery?
Delivery: This will depend on the type of skeletal dysplasia and will be discussed with you by your Fetal Center team.
Place of delivery: The baby should be delivered at a hospital that is prepared to handle the special care sometimes needed for newborns with a skeletal dysplasia. The hospital should have a neonatal intensive care unit (NICU) that can provide this care.
What will happen at the time of delivery?
The Fetal Center team will counsel the parents about what to expect at the time of delivery based on findings from the patient's ultrasound, MRI and other testing if performed. There are a range of possible outcomes, which may include stillbirth or fetal demise in the neonatal period. However, not all dysplasias have severe medical problems.
After delivery, further testing may be recommended to pinpoint the type of dysplasia.
What are the long-term outcomes and considerations?
The long-term outlook for a child born with a skeletal dysplasia depends on the type of dysplasia. Often this can be difficult to predict during pregnancy and better predictions can be made after evaluating the newborn. While some babies do not reach full term, are born premature or have severe complications after birth, not all skeletal dysplasias are associated with life-limiting medical problems. For example, individuals with achondroplasia lead relatively normal lives. Achondroplasia is one of the most common types of dwarfing conditions.
Many online and community support groups can provide resources and guidance to families facing a skeletal dysplasia diagnosis, including groups such as Little People of America.
For more information about skeletal dysplasia or to schedule a consultation with a genetic counselor or fetal specialist, contact The Fetal Center at (832) 325-7288.
Authors: Kenneth Moise, Jr., M.D., Jacqueline Hecht, Ph.D., Joanne Nguyen, M.D., Rebecca Carter, M.S., C.G.C., McGovern Medical School at UTHealth
To learn more about pediatric orthopedics and fetal skeletal dysplasia, click here.