Please note: Dinosaur Comics on Canada (Dinosaur Comics is just about the best thing ever.)

From The Story of V, page 276:

"One of the most startling recent discoveries about the characteristics of orgasm is that these muscle contractions are one of the first sensations humans ever experience. That is, incredibly, both female and male foetuses orgasm in the womb. The following description of female orgasm in utero is from the American Journal of Obstetrics and Gynaecology, and was reported by two Italian doctors during a routine pre-birth ultrasound scan.

We recently observed a female fetus at 32 weeks' gestation touching the vulva with the fingers of the right hand. The caressing movements were centred primarily on the region of the clitoris. Movements stopped after 30 to 40 seconds and started again after a few minutes. Furthermore, these slight touches were repeated and were associated with short, rapid movements of pelvis and legs. After another break, in addition to this behaviour, the fetus contracted the muscles of the trunk and limbs, and then clonicotonic movements of the whole body followed. Finally, she relaxed and rested. We observed this behaviour for about 20 minutes. The mother was an active and interested witness, conversing with observers about her child's experience.

The authors concluded their astonishing account of in utero female orgasm by saying: 'The current observation seems to show not only that the excitement reflex can be evoked in female fetuses at the third trimester of gestation but also that the orgasmic reflex can be elicited during intrauterine life.' Perhaps it's not surprising to hear that male foetuses too have been found pleasuring themselves in the womb. Indeed, it's not unusual for parents-to-be to see their embryonic son grasping his erect penis in utero, while moving his hands in a repetitive masturbatory fashion, for up to fifteen minutes at a time.

Well, yeah. I mean, with 9 months to hang out by yourself, who could keep their hands off of this?