40 with no children, set to have a Labiaplasty surgery with clitorial hood reduction. Will I lose sensation?

Thank your your questionThe answer depends on the procedure that is performed and the quality of surgeon. You should do your homework and look at several before and after photos with patients with an appearance similar to yourself as well as read many reviews. Become knowledgeable. You can get more info with the video below

You currently have aesthetic and functional concerns that warrant a properly performed labiaplasty. Your questions are great and you should make sure they are answered to your satisfaction. If performed well you will NOT lose any feeling and you will have greater confidence and comfort with sex. This in turn results in an improved sexual experience.
You could show photos to your surgeon of your desired results to see if this is a possibility for you. You could find many examples of Labiaplasty with Clitoral Hood Reduction in the link below. You should get a second opinion and perhaps you'll need to travel to get the best results. From that link you can schedule a virtual consultation via phone or zoom, at which time we can discuss in depth your anatomy, expectations and concerns. Women from all over the world travel to my Center for their Intimate Makeover.
Best of luck,

Among the hundreds of labiaplasty and hood reduction surgeries that I’ve performed, I don’t have any patients that have changes or loss of sensation. If anything, I hear more reports of improved sensation and improved sexual response after labiaplasty and clitoral hood reduction. Sometimes the excess tissues are source of pain with intercourse due to chafing, pulling, and pinching. A labiaplasty relieves pain from these issues and also is empowering by reducing self consciousness for women to feel more comfortable with their sexual response. Best to find an expert surgeon so that your results are exceptional before and after photos, videos and reviews are the best way there.