In utero cleft lip repair in A/J mice.

Reconstructive in utero microsurgery for repair of unilateral cleft lips has been technically achieved in the A/J mouse fetus. The period of gestation was undisturbed, and following birth, the gross and histologic appearance of the lips was nearly normal with no evidence of scar formation. The absence of a lip scar after human cheiloplasty may require the as yet undefined advantages of fetal wound healing.