Question

A nurse is performing an admission assessment on a client who had a recent positive pregnancy test. The first day of her last menstrual period (LMP) was May 8. According to Nagele's rule, which of the following dates should the nurse document as the client's estimated date of birth (EDB)?

a. January 15
b. February 15
c. February 1
d. March 1

Answer 1

The estimated date of birth (EDB) according to Nagele's rule, given the LMP of May 8, is February 15. Nagele's rule involves adding 7 days to the LMP, subtracting 3 months, and adding 1 year to estimate the due date.

Step-by-step explanation:

To calculate the estimated date of birth (EDB) using Nagele's rule, you add seven days to the first day of the last menstrual period (LMP), subtract three months, and then add one year. Given the client's LMP of May 8, we first add seven days, resulting in May 15. Next, we subtract three months, which brings us to February 15. Finally, we add one year, affirming that the date remains in the next calendar year. Therefore, according to Nagele's rule, the estimated date of birth would be February 15.

Using Nagele's rule is a standard practice in obstetrics as it provides an easy calculation method based on a typically more memorable date, the LMP, than the exact conception date. Since LMP includes an assumption that conception occurs approximately on day 14 of a woman's menstrual cycle, Nagele's rule sets the due date at 284 days from the LMP, which represents a full-term pregnancy lasting around 40.5 weeks. It is worth noting that the exact date of delivery can vary due to individual differences in menstrual cycles and the length of pregnancy.