Quote:
Originally Posted by chelseamorning15
Hi everyone,
We got a BFP on Sunday morning and are so excited!!! I still can't believe it and need to decide on a midwife
Anyway...I have a seemingly silly question. Why is it that I would be considered 4 weeks pregnant if I conceived 2 weeks ago? Shouldn't I be considered 2 weeks pregnant instead? I understand that this calculation is based on the first day of my last period, but it doesn't make sense to me
Regardless, it's great to be further along even if I don't understand why! Maybe I just need to accept it
Any insight?
Thanks so much,
Rebecca
|
Congratulations! Here's an answer to your question. They calculate gestational age based on the date of your last monthly period (LMP), so that literally, the moment the sperm meets the egg, the baby is "officially" two weeks old.
The reasons why they do this are fairly commonsensical (sort of):
1. Not all women know precisely on what day they had intercourse.
2. Not all women know precisely on what day they ovulated.
3. Not all women know precisely on what day sperm met egg.
Okay, now even assuming the ideal case, that a woman DOES know all these things (e.g., that she ovulated on the 14th, that she had sex on the 14th also and on NO OTHER DAY that month at all), here's one thing she and no one else but maybe the embryo and God know, and that's what day the fertilized embryo implanted.
Surprisingly, that can take as many as six days AFTER fertilization in the fallopian tubes. It's not until the embie implants that it starts constructing a placenta for itself and making human chorionic gonadotropins (HcG) -- the chemical detected in the urine pregnancy test.
Soooo, the embryo could have implanted right then and there on the 14th...or nearly a week later on the 20th. The clock really *really* starts ticking from when the embryo implants and starts making itself a placenta. All in all, given those factors, it's easier to go by the woman's LMP. It's also the reason for the early transvaginal ultrasounds, because babies develop nearly uniformly for the first two trimesters. In other words, if they are at X length, it's easy to see that they are X number of weeks old, if that makes any sense.
Oh, big thing!!! I don't know what you want to do regarding prenatal testing, but PLEASE, PLEASE, PLEASE make sure you have
as absolutely accurate a gestational age as possible BEFORE you do one of the prenatal tests known as the "AFP Test" or sometimes the "triple screen." This test tests the amount of maternal alphafetoproteins in your blood. The AFP rises at a predictable steady rate relative to gestational age unless something is wrong. Too much AFP indicates a strong likelihood of there being a neural tube defect like spina bifida; too litte indicates a strong likelihood of Down syndrome or other chromosomal abnormality.
The thing is, if the test is off by even a week, it will give back a false result -- and to hear that your baby MIGHT have Down or MIGHT have spina bifida is about the very last thing you want to hear when you're pregnant.
Trust me.
For instance, in my case, my doctor -- may he come back as one of his own patients -- would NOT listen to when I told him the baby was conceived. (I kept a calendar and I knew it had to be one particular day.) He went by the date of my LMP, two weeks earlier, and wrote down on the test that she was 17 weeks old. Actually, she was 15.
Anyway, the test came out as "too low" a quantity of AFP. This meant that according to the test, there was a strong possibility she had Down syndrome.
It was like getting kicked in the belly. We had a level III ultrasound and they took multiple measurements (biparietal diameter, femoral length, nuchal fold, et cetera) and calculated her dates as being...surprise! Fifteen weeks old. Therefore, she was probably normal, but my happy little balloon of complacency had been completely popped and I finally requested an amniocentesis because only the amnio can tell you
beyond all doubt if there are chromosomal abnormalities of that type. Even the level III ultrasounds can miss some subtle signs.
So anyhow, if your position is, "I will accept whatever God / Allah / YHWH / Kali / karma/ Hera / Fate / Life gives me no matter what," then skip the test.
If your position is somewhat different, you might want to consider skipping to the amnio if you're a "geriatric pregnancy," which most OBs define as being over thirty-five.
: I know many MDC folks may not agree with this level of intervention, and I can't say that I blame them. Your call.
I wish you well!
