Labiaplasty: Are Labia Lengths a Reliable Metric?
Labia length is sometimes used to determine candidacy for labiaplasty insurance-coverage. Classification systems also use this measurement, often defining longer lengths as labia “hypertrophy.” Given the malleability of labia tissue, lengths can vary depending on whether tension is applied during measurement. The aim of this project is to assess the reliability of labia length as a standard metric.
Methods/Technique:
All patients undergoing labiaplasty from January 2017 to October 2022 underwent chart review. Variables collected included: length of the portion of labia minora exposed below the labia majora, both while relaxed and while stretched. The total length, sulcus to edge, was also measured in the lithotomy position, with the labia supported, but unstretched. Linear regression, Pearson’s correlation coefficient and coefficient of determination were performed. Descriptive statistics were also calculated.
Results/Complications:
Thirty-nine of 100 charts had complete information. The average age was 33. The length of the relaxed exposed labia averaged 10.3 mm (right) and 11.7 mm (left). The lengths of the stretched exposed labia averaged 21.9 mm (right) and 24.1 mm (left). Stretching increased the lengths 248% (right), standard deviation of 107%; and 256% (left), standard deviation of 197%. The total labia lengths averaged 32.5 mm (right) and 34.1 mm (left). When comparing the relaxed exposed with the total labia lengths, Pearson correlation coefficient (r) values were 0.73 (right) and 0.70 (left); coefficient of determination (r2) values were 0.53 (right) and 0.49 (left). (Figure 1) When comparing stretched exposed with the total labia lengths, Pearson correlation coefficient (r) values were 0.76 (right) and 0.76 (left); coefficient of determination (r2) values were 0.57 (right) and 0.58 (left). (Figure 2) When comparing the relaxed exposed with the stretched labia lengths, Pearson correlation coefficient (r) values were 0.87 (right) and 0.89 (left); coefficient of determination (r2) values were 0.75 (right) and 0.79 (left). (Figure 3)
Conclusion:
Lengths of exposed labia change over 200% bilaterally, from relaxed to stretched, with huge standard deviations of over 50% of the mean values. Because these measurements were taken by a single surgeon, it is possible that lengths measured by a group of practitioners could have even greater variability. Well-defined measurements taken under consistent tension, whether relaxed, stretched, or total, have a positive correlation and consistency. Labia lengths measured under unspecified tension render the classification systems and insurance-based labiaplasty candidacy on which they are based unreliable.