Maternity Nursing Q 73

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If the LMP is Jan. 30, the expected date of delivery (EDD) is:

  

     A. Oct. 7

     B. Oct. 24

     C. Nov. 7

     D. Nov. 8

    

    

Correct Answer: C. Nov. 7

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Based on the last menstrual period, the expected date of delivery is Nov. 7. The formula for Naegele’s Rule is to subtract 3 from the month and add 7 to the day.

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Option A: This is an incorrect EDD. An average pregnancy lasts 280 days from the first day of the last menstrual period (LMP) or 266 days after conception. Historically, an accurate LMP is the best estimator to determine the due date.

Option B: Oct 24 is incorrect. It is prudent for the obstetrician to get a detailed menstrual history, including duration, flow, previous menstrual periods, and hormonal contraceptives. These factors are used to determine the length of her cycles and ovulation period.

Option D: Nov 8 is not the correct, exact EDD. Having accurate birth dating might decrease maternal/fetal morbidity and or mortality through timely consulting with experts in the field of maternal-fetal medicine, obstetrics/gynecology, oncology, or genetics. For example, fetal genetic abnormalities can be detected in a timely fashion providing the mother with sufficient time to make a lifetime decision.

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