nondisjunction - meiosis in which there is a failure of paired homologous chromosomes to separate; results in an abnormal number of chromosomes in the daughter cells.
What Date? is a simple, freeware date calculator for Windows. Enter a date and interval and press calculate to find any date in the future or past. What Date will recognize any date format which Windows can understand (date formats as set in Control Panel). I wrote this because many people emailed asking; Is there a simple way to find a date given a start date and interval?.
The date of LMP is known by most women so doctors use this date as a starting point for pregnancy. From your LMP they will add 280 days and this will give your Estimated Due Date or EDD. In general, all doctors agree that pregnancies, when using the LMP dating technique, average approximately 280 days or 40 weeks.