An original histological method for studying the volar skin of the fetal hands and feet.

AIMS

The human fetal period of life is when there is complete development of the dermatoglyphic pattern. However, to date not enough is known about the differentiation of the papillary terrain during prenatal life and which mechanisms are involved in this differentiation. The aims of the present study are to contribute to the clarification of the embryogenesis of the papillary ridges and to compare their development on the hands and feet.

METHODS

The hands and feet of 35 human embryos and fetuses were examined in the present study. We used a new and original method of orientation. The right hand with right foot or left hand with left foot of each embryo/fetus were placed together into one paraffin block. Three different planes of orientation were used.

RESULTS

Volar pad development and papillary ridge formation are identical on hands and feet, but the developmental stages on feet lag one week behind those of hands. Papillary ridge embryogenesis follows the cranio-caudal developmental direction. After developmental week 14 the configuration of the future dermatoglyphic pattern has already ocurred at the dermo-epidermal junction. We consider the 6(th) month of prenatal development to be the gestational age when the papillary ridge development is completed.

CONCLUSION

Our observations lead to the conclusion that the increased vascularization of dermis considerably affects papillary ridge formation.