Fetal biparietal diameter as a predictor of a mature lecithin/sphingomyelin ratio.

The records of 148 patients who had undergone simultaneous determination of fetal biparietal diameter and lecithin sphingomyelin ratio were reviewed. The results of the lecithin sphingomyelin determination could not be predicted with an acceptable degree of accuracy utilizing the fetal biparietal diameter. When patients were grouped by maternal disease, no significant difference between diabetic and control patients was noted. Other subgroups were too small to allow a valid statistical comparison.