Diet and Health FAQ

Tagged As: First Trimester

Question:
Just trying to figure out if I'm almost at the end of the first trimester (12wks on Fri) or if I have two more weeks to go. No particular reason, it's just that there are lots of references to risks decreasing at the end of the first trimester, things that start to happen in the second trimester, etc. So, most sites I've seen refer to the first 3 months as the first trimester. That would imply it ends at 12 wks. However, if pregnancy lasts at least 40 wks (and well all know it's more like 41 wks), then that would mean the first trimester would be at least 13 wks, if not 14 or 15 because the first two weeks aren't really part of the actual pregnancy. So, anyone have definite info, or a definite opinion on when the first trimester officially ends?

Answer:
There's no magic day when the risk of things gets lower, but if you have made it to twelve weeks, the baby is in the fetal period (as opposed to the embryonic period where life is crazy for the little developer), the placenta has taken over hormone production, and so forth. The first three months is not 12 weeks gestation. When you are 12 weeks you've only been pregnant for about 10 weeks, which is 70 days, which is about 2 months 10 days. So you have to give it to 14-15 weeks before you are 1/3 done baking your child (assuming a natural gestation to an average of about 41 weeks since LMP or 9 months). There is no evidence to support 40 weeks as average gestation naturally, although with so many inductions and bad prenatal advice, I bet it is average in reality. But of course many of us here are going to incourage you to let the system work the way it is designed to work. ;) 9 months really is longer than 9x4=36 weeks. It's even longer than 10x4=40 weeks. But 9 months is not longer than 9 months. Both my kids cooked about 9 months. My daughter was conceived on 1/13/03 and born 10/17/03 (barely, had the midwife not interfered she probably would have been born at 9 months, 3 days at 41+3). My son was conceived 4/28/04 and born 1/27/05, one day short of 9 months, at 41+1. I think officially it's 12 weeks, then the 2nd trimester is 12-28 weeks which is very long, as far as the risks decreasing, they start to fall before you hit 12 weeks and continue to decrease afterwards. I like to think to the trimesters as feelings, 1st is grotty, 2nd is blooming, 3rd is uncomfortable and tired, this pregnancy I was blessed with a very long 2nd trimester, started maybe 15ish weeks, but went on past 30. I think I understood about every third sentence! (had to laugh at the But 9 months is not longer than 9 months sentence) :) I do get the general gist though. I know avg first preg. is 41w1d when uninduced, so I was surprised when my OB nurse told me I would be induced if I got to 41wks. Fortunately, my OB was more educated and basically said that they start to allow inductions at 41 wks because they were getting too many patients complaining about them refusing to induce till 42 wks. These are probably the same patients that want to schedule a C-section for convenience.