Comparison of demographic and defect characteristics among different developmental stages of congenital limb reduction defects.

This study investigates how the timing of the development of limb reduction defects (LRDs) is associated with selected demographic, medical variables and defect characteristics. The LRD cases (n = 281) were ascertained from the Congenital Malformations Registry of New York State among 1983-1987 births. Cases were classified according to five stages of gestation based on when their earliest LRD developed. A control group consisted of a systematic random sample (n = 327) of non-malformed livebirths. Demographic and LRD characteristics were abstracted from birth certificates and medical charts. Among LRDs, the defects that occurred in the earlier stages of gestation were found to be more complex problems, compared with those developing in the later stages. Middle or late stage LRDs tended to occur more often with syndactyly than early stage LRDs, and had significantly higher frequencies of non-white infants compared with controls. In addition, some perinatal complications, pre-term delivery and low birthweight were positively associated with any LRD. Our findings suggest that the timing of a disturbance in limb development is important in terms of LRD characteristics. Demographics did not vary consistently with the stage of LRD development. Further studies testing this classification technique are suggested.