Is the cost of gender or ***** selection as part of my IVF treatment considered an 213(d) allowable expense with the IRS? Must I also have a diagnosis of infertility?

Yes, the treatment is an allowable expense. See Tax Court Allows Medical Deduction for Sex Change Operation

Publication 502, Medical and Dental Expenses states:

Medical expenses are the costs of diagnosis, cure, mitigation, treatment, or prevention of disease, and for the purpose of affecting any part or function of the body. These expenses include payments for legal medical services rendered by physicians, surgeons, dentists, and other medical practitioners. They include the costs of equipment, supplies, and diagnostic devices needed for these purposes. Medical care expenses must be primarily to alleviate or prevent a physical or mental disability or illness. They don't include expenses that are merely beneficial to general health, such as vitamins or a vacation.