Polysomnography is used to diagnose, or rule out, many types of sleep disorders including narcolepsy, idiopathic hypersomnia, periodic limb movement disorder (PLMD), REM behavior disorder, parasomnias, and sleep apnea.
Calculating Due Date: Estimated Due Date. Based on the last menstrual period, the estimated due date is 40 weeks from the first day of the period. This is just an estimate since only about 5% of babies are born on their estimated due date.
Step 2. Use that date of your last menstrual period and count ahead on your calendar 280 days, or 40 weeks, to determine your estimated due date. For example, if your last menstrual period started on Nov. 1, you would count forward 40 weeks for a due date of Aug. 8.