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.
Use the first day of the last menstrual period to calculate the due date. The quick way to do it in your head is to count backwards 3 months from the first day of the LMP, then add 7 days. So if the LMP was 8/15, the 3 months backwards is 5 (May) plus 7 days added to the 15th=22, so the due date is May 22.