I'm wondering if a Tummy Tuck could have a negative affect on the ability for a woman to have an orgasm.

There is no direct correlation between abdominoplasty and orgasm in my experience or in the literature. Certainly you will have temporary sensation loss or decrease in the lower abdomen and possibly in the superior portion of the mons depending on far along you are from the surgery. 

Perhaps your post op focus on the surgery prevents you from enjoying the other aspects of life. Talk to your ASPS physician. 

Without commenting on the numerous possible causes for "anorgasmia," or lack of the ability to orgasm, and assuming that you have been able to orgasm up until now, I would not expect a tummy tuck itself to change that.  While you will almost certainly experience some numbness in the skin of the lower abdomen above the incision line, and possibly in the upper part of the pubic mound early after the surgery, this should not involve any of the erogenous zones of the genitalia or the nerve supply which is most commonly associated with production of orgasm.  Those nerves come from deep within the pelvis and exit under the pubic bone high up in the groin and follow a course to the clitoris, vulva, and vagina.  In a standard tummy tuck, they would most certainly be out of the "line of fire."  While there may be some temporary swelling in the labia, bruising in that area, or even some alteration in sensation there early on, I would expect this to resolve within weeks to a couple of months, and again, this should not have any overall or lasting effect on erogenous sensation.  As techniques sometimes vary from surgeon to surgeon, be sure ask your surgeon about this too, and that way you will be reassured that the exact technique that your surgeons recommends for you is consistent with what I am describing here.  You should always consult with only board certified plastic surgeons for this kind of surgery, as they are the only ones properly accredited to perform this kind of surgery in the US.  In addition to being certified by the American Board of Plastic Surgery, your surgeon should also voluntarily participate in the Maintenance of Certification program administered by that board. This is the best way to know that your surgeon not only has the best training and experience for the procedure, but that he or she has maintained currency in the certification requirements as opposed to practicing on a "lifetime" certificate which has only been reviewed once at the beginning of his or her career. For more information on this you can visit ABplsurg.org, ABMS.org, and certificationmatters.org .   Good luck.