A client tells the nurse that the first day of her last menstrual period was July 22, 2008. What is the estimated date of delivery?

Correct option is B

To estimate the Expected Date of Delivery (EDD), Naegele’s Rule is applied:
EDD = LMP + 1 year – 3 months + 7 days
LMP = July 22, 2008 → Add 1 year = July 22, 2009 → Subtract 3 months = April 22, 2009 → Add 7 days = April 29, 2009.
Hence, the correct EDD is April 29, 2009. This rule is universally accepted in clinical obstetrics and validated by standard references like Williams Obstetrics and ACOG.

Explanation of options:
(a) May 7, 2009 – This date is too late; it exceeds the normal 280-day gestational period calculated from the LMP.
(b) April 29, 2009 – Correct answer. It is calculated using Naegele’s Rule and falls exactly 280 days (40 weeks) from the LMP.
(c) April 22, 2009 – This date omits the final step (adding 7 days) of Naegele’s Rule, making it incomplete.
(d) March 6, 2009 – This date is too early; it reflects a calculation error or misunderstanding of the rule.