Autopsy standards of body parameters and fresh organ weights in nonmacerated and macerated human fetuses.

Standards for body parameters and organ weights are important tools in fetal and perinatal pathology. Previously there has been only a weak emphasis on the effect of maceration on dimensions and weights. This study provides autopsy standards for body weight, body dimensions, and fresh organ weights for nonmacerated fetuses and for mildly, moderately, and markedly macerated fetuses at 12 to 43 weeks of gestation. Cases were selected from a consecutive series of 1800 fetal and perinatal autopsies. Cases with malformations, hydrops, infection, or chromosomal abnormality, fetuses from multiple births, and infants who lived longer than 24 h were excluded. In each case the maceration was graded and body weight and 4 body dimensions were recorded before organ examination. Organs were weighed immediately and before fixation. Growth curves were fitted according to appropriate mathematical methods and the effects of maceration on each value were tested statistically. We found that weights of the liver, thymus, and spleen markedly decrease with increasing maceration. The weights of the lungs, kidneys, and adrenals decreased modestly, whereas weights of the heart and brain changed only slightly. Body length increased slightly with maceration, whereas body weight and head circumference were unaffected. User-friendly charts and tables of mean values and standard deviations for nonmacerated and macerated fetuses are provided.