Primordial dwarfism is a rare form of dwarfism that results in a smaller body size in all stages of life beginning from before birth. More specifically, primordial dwarfism is a diagnostic category including specific types of profoundly proportionate dwarfism, in which individuals are extremely small for their age, even as a fetus. Most individuals with primordial dwarfism are not diagnosed until they are about 3 years of age.
Medical professionals typically diagnose the fetus as being small for the gestational age, or as having intrauterine growth disability when an ultrasound is conducted. Typically, people with primordial dwarfism are born with very low birth weights. After birth, growth continues at a stunted rate, leaving individuals with primordial dwarfism perpetually years behind their peers in stature and in weight.
Most cases of short stature are caused by skeletal or endocrine disorders. The five subtypes of primordial dwarfism are the most severe forms of the 200 types of dwarfism, and it is estimated that there are only 100 individuals in the world with the disorder. Other sources list the number of persons currently afflicted as high as 100 in North America.
It is rare for individuals affected by primordial dwarfism to live past the age of 30. In the case of microcephalic osteodysplastic primordial dwarfism (MOPD) type II there can be increased risk of vascular problems, which may cause premature death.