In this video, we demonstrated 10- and 11-week fetal penis and clitoris. At 10 weeks, fusion of the urethral folds is noted in the proximal shaft of the penis. Co-expression of both neuronal and endothelial markers is observed at the fusion point where penile raphe begins to form. In contrast, in the clitoris, without the fusion process, vestibular folds remain as labia minora. At 11 weeks, in the penis, fusion of the urethral folds advances distally to the penile glans. Also, a difference in pattern of vascular distribution in the penile and clitoral shaft is noted.
Our method allows us to examine the developing penis and clitoris in great detail in 3D. This technique enables us to compare microscopic anatomical differences from different angles, which are not previously described.