# Help with OB!!!

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i'm studying for the nclex, and i got this problem for one of the sample tests.

q. the nurse cares for clients in the prenatal clinic. a client comes to the clinic for a prenatal visit on june 6. her last menstrual period was december 10. the nurse expects the client's fundal height to measure

1.) 24cm

3.) 28cm

4.) 30cm

i know how to calculate edc and i know that how ever many weeks = the cm that the nurse should expect. i just don't get how they got 26 weeks? i put 24 because dec10-june6 is about 6 months, 6x4weeks=24weeks. is this wrong??

Specializes in Oncology.

You have to consider that with the weekly dating system, at the moment of conception a woman is two weeks pregnant.

So calculating from the LMP (dec 10), whatever weeks I get, I would add 2 weeks?

Thank you very much!

My answer comes from the perspective of a mom not as a nurse. The LMP IS two weeks prior to conception. Did you take into consideration that most months are 4 weeks and two days so over the span of six months there would be about 'two weeks' worth of extra days....

Use Naegele's rule to determine due date: add one year to LMP, subtract three months, and add seven days due date = September 17 (40 weeks)

Now add the days left in June (24), July (31) August (31) September (17) and divide by 7 = 14 weeks.

Subtract 14 from 40 = 26 weeks X 1cm/wk = 26 cm

Specializes in Pedi.
i'm studying for the nclex, and i got this problem for one of the sample tests.

q. the nurse cares for clients in the prenatal clinic. a client comes to the clinic for a prenatal visit on june 6. her last menstrual period was december 10. the nurse expects the client’s fundal height to measure

1.) 24cm

3.) 28cm

4.) 30cm

i know how to calculate edc and i know that how ever many weeks = the cm that the nurse should expect. i just don't get how they got 26 weeks? i put 24 because dec10-june6 is about 6 months, 6x4weeks=24weeks. is this wrong??

yes, it's wrong because every months except for february is longer than 4 weeks by 2-3 days. over the course of 6 months, that extra 2-3 days is going to equal an extra week or 2.

if you're thinking that december 10 - june 6 is about 6 months, you should be thinking that's about 180 days ... divided by 7 days/week= 25.7.