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.
Last menstrual period. The most common method of calculating your due date is by taking the first day of your last menstrual period (LMP), adding 7 days, and then counting backward 3 months. For example, if your LMP started on March 20, you would add 7 days to get March 27, and then subtract 3 months to get a due date of December 27.