A nurse is calculating the estimated date of delivery for a client who reports that the first day of her last menstrual period was August 10. Using Nägele’s Rule, which of the following is the client’s estimated date of delivery?
A.
May 20.
B.
May 3.
C.
May 13.
D.
May 17.
The correct answer and Explanation is :
To calculate the estimated date of delivery (EDD) using Nägele’s Rule, follow these steps:
- Identify the First Day of the Last Menstrual Period (LMP): In this case, the LMP is August 10.
- Add 280 Days (40 Weeks) to the LMP: This accounts for the typical 40-week pregnancy duration from the start of the last menstrual period.
- August 10 + 280 Days
- Convert Days into Months and Days: To make this calculation simpler, it’s often helpful to break it down month by month.
- August: August has 31 days, so from August 10 to August 31 is 21 days.
- September: 30 days
- October: 31 days
- November: 30 days
- December: 31 days
- January: 31 days
- February: 29 days (2024 is a leap year)
- March: 31 days
- April: 30 days
- May: Since we are calculating for May, we will need to count the days in May.
- Calculate Total Days:
- Days remaining in August: 21 days
- Days in September: 30 days
- Days in October: 31 days
- Days in November: 30 days
- Days in December: 31 days
- Days in January: 31 days
- Days in February: 29 days
- Days in March: 31 days
- Days in April: 30 days
- Days to reach 280 days: 280 – (21 + 30 + 31 + 30 + 31 + 31 + 29 + 31 + 30) = 280 – 243 = 37 days into May.
- Add 37 days to May 1st to get May 7th Thus, the estimated date of delivery is May 17.
So, the correct answer is:
D. May 17
Explanation
Nägele’s Rule is a standard method used to estimate the delivery date based on the first day of the last menstrual period. By adding 280 days (which is the duration of a typical pregnancy) to the LMP, we approximate the EDD. This rule assumes a regular 28-day menstrual cycle. Adjustments are made for longer or shorter cycles, but this method is broadly effective for standard cycles.