Using Nägele's rule, what would be the estimated date of birth for a client whose last menstrual period began on October 20, 2012?

To determine the estimated date of birth using Nägele's rule, you start with the date of the last menstrual period (LMP) and follow these steps: add one year, subtract three months, and add seven days.

Using the provided date of October 20, 2012, first, add one year, which brings you to October 20, 2013. Next, subtract three months, landing on July 20, 2013. Finally, adding seven days brings you to July 27, 2013.

Thus, the calculated estimated date of birth is July 27, 2013, which confirms that this is the correct option. This method is commonly used in obstetrics to estimate the due date based on a regular 28-day menstrual cycle, helping healthcare providers plan further monitoring and intervention during pregnancy.