Does the uterus contribute to sexual response or desire?
As described, the uterus definitely plays a role in sexual response. It undergoes vascular congestion during arousal and then rapid drainage of the vascular congestion after orgasm (climax).
Also there are rapid small amplitude contractions of the uterine muscle during orgasm as well as contractions of the vagina and urethral muscles. After hysterectomy those uterine contractions with orgasm disappear although some contractions are still present in the lower genital tract.
Most women will report a difference in orgasm after hysterectomy but not necessarily less enjoyable. There is a current trend among some physicians and patients to perform or request a subtotal hysterectomy in which the main uterine muscle and lining are removed (body of uterus) while leaving the cervix.
As you can imagine, it is very difficult to study whether the small amount of muscle in the cervix (it is mostly just connecting tissue and not as much muscle) preserves any degree of uterine contractions during orgasm. I would guess that the cervix alone would not contribute that much.
The genital changes that take place during a sexual response according to the Masters and Johnson classification are:
- Excitement phase - vaginal lubrication, vasocongestion, separation of the lips of the vaginal opening (labia majora), vaginal walls thicken, early uterine elevation, lengthening of the vagina
- Plateau phase - uterine elevation, clitoral elevation, vaginal expansion, maximum lubrication, outer third of vagina forms orgasmic platform
- Orgasm phase - uterine contractions, tenting effects of vagina, orgasm contractions
- Resolution phase - sexual flush disappears, changes go in reverse
As you can see, most of the same changes will take place after hysterectomy as before hysterectomy, except uterine elevation and uterine contractions and the vasocongestion that takes place in the pelvis above the vagina.
The problem with most of the scientific studies that have been done on the effect of hysterectomy on sexual response, is that the investigators often lumped together many situations which confuse whether or not a postoperative change is due to the removal of the uterus alone or due to other factors.
For example it is well known that menopause itself reduces sexual desire and sexual response because of the loss of estrogen. Even if estrogen is replaced, it can be less than perfect at restoring preoperative sexual desired and response.