Question about disability insurance

My employer offers long term and short term disability insurance. I realize this is highly fact-specific and could be jurisdiction-specific, but in general, is it considered fraudulent to begin a disability insurance policy if you have a reasonable expectation of using it in the somewhat near future, or is it fairly common and accepted practice to enroll at the next open enrollment period if you expect to need the insurance?

For example, if you may need major surgery in the next few years or if you may get pregnant, but it's not urgent for you to have surgery and you're not pregnant right now, is it unethical or fraudulent for you to get disability insurance with that knowledge? Do you have to answer a health questionnaire or give the insurance company access to your medical records prior to getting disability insurance?