Patterns of body and visceral growth in human prenates with clefts of the lip and palate.

Objective: To address the hypothesis that human prenates with birth defects such as clefts of the lip and palate show growth patterns in which body size and visceral growth are aberrant for prenatal age.

Methods: Body size and organ weight measurements were derived from a cross-sectional population sample of 167 legally donated human embryos that were representative of key periods in visceral organogenesis and growth. Measurements included those of overall body size (i.e., length and weight) and weights of major organs. Data were analyzed for two comparative (age-matched) groups consisting of 120 typical-for-age "control" and 47 specimens showing the three typical cleft types. Organ weight data for the entire cleft group and for each of the three cleft subgroups were compared with those of the control group.

Results: Cleft specimens showed crown-rump body sizes that were within one standard deviation of the control group. Among the entire cleft sample, each of the organ weight values was generally consistent with the organ weights observed for the age-matched control group. When organ weights for the cleft group differed from the controls, with one exception, some organs showed either increased or decreased organ weights. One remarkable exception was with lung weights, which were reduced for each of the prenates across the three cleft types. Among the three cleft groups, fetuses with cleft lip and palate showed the highest percentage of organ weight discrepancies (i.e., smaller than expected) as compared with the group with cleft palate, which showed the lowest. CONCLUSIONS; Organ weight aberrancies were observable (whether increased or reduced weights), and such aberrancies were not apparent until approximately 24 weeks (fertilization age).