When does the first trimester actually end?

[FiddleFit]

Hi! I'm a bit confused. I've seen it stated in different books that the first trimester ends at 12 weeks, and at 14 weeks. Referencing the first day of the last menstrual cycle as the start of the pregnancy, when is the first trimester officially over?

Thanks!
Sandra

 

[sunnydelite]

the first trimester ends at the end of your thirteenth week.
congrats..you are almost there

 

[kristi]

Don't feel bad Sandra. I was wondering the same thing. It seems like every website has it being a different week. The main one I go to shows the 2nd trimester beginning with the 13th week. I think I'll stick with SunnyDs suggestion. If 40 weeks is divided by 3 then it would work out to be 13.3 so I'm considering my 1st trimester over with the beginning of my 14th week. Boy do I hate making my 1st trimester longer than I want it to be!!

 

[FiddleFit]

I hear you Kristi! There certainly appears to be no consensus on this. I asked my friend who is a nurse, and she tells me that she was taught 12 weeks was the end of the first trimester. I'm thinking that people are using different parameters to define a trimester. I'm not worried about this issue, just curious because it seems to be so different according to who your source is. Personally I'm starting to notice an increase in energy and a decrease in my stomach troubles and food aversions, so I know I'm in the homestretch of the first trimester, regardless of how it's defined! And beside, my belly is ready for me to start saying that I'm in the second trimester LOL! Oh dear, sitting on the couch all day is not conducive to keeping off excess weight!

Cheers!
Sandra

 

[autumn]

I guess that really depends on how many weeks your baby's gestation lasts. Williams Obstetrics, "The Book" of OB, defines the first trimester as the first 14 weeks (if I remember correctly). In nursing school, I was taught 12 weeks.

I say go for 12 weeks.