Ultrasonographic observation of a female fetus' sexual behavior in utero
We recently observed a female fetus at 32 weeks' gestation touching the vuvlva with fingers of {her} right hand. The caressing movement was centered primarily on the region of the clitoris. Movements stopped after 30 to 40 seconds, and started again after a few moments. Further, these light touches were repeated and were associated with short, rigid movements of the pelvis and legs. After another break, in addition to this behavior, the fetus contracted the muscles of the trunk and limbs, and the climax, clonicotonic movements {rapid muscle contractions} of the body, followed. Finally she relaxed and rested. We {several doctors and the mother} observed this behavior for about 20 minutes.
source: Article 'Ultrasonographic observation of a female fetus' sexual behavior in utero' by Dr. Giorgio Giorgi & Dr. Marco Siccardi; www.huffingtonpost.com/2013/06/19/michael-burgess-fetal-masturbation_n_3466651.html; American Journal of Obstetrics and Gynecology; 1996