Saturday, January 15, 2011

How's That Work??

I have had several people confused about how to date a pregnancy... I have said conception of this baby was on Christmas Eve/Christmas Day and that I am 5 weeks pregnant. But, Christmas wasn't five weeks ago..... so how does this work??? Well, let me explain!! :-)

Pregnancy is conveniently dated in weeks (40 weeks) starting from the first day of your last menstrual period. The first two weeks of "pregnancy", is when the follicles that carry the eggs are growing in the ovaries. Typically there is one dominant follicle that grows to maturity. Two weeks (14 days) into the woman's cycle the egg bursts out of the follicle and is pulled into the fallopian tube. This is ovulation. Fertilization of the egg happens within about 24 hours of ovulation then implants into the uterus approximately 7-10 days later. After implantation occurs the woman's body starts producing a hormone called human chorionic gonadotrophin (hCG). This hormone doubles every 2-3 days and is able to be detected by home pregnancy tests several days after implantation. Pregnancy last on average 266d days from fertilization (38 weeks) or 280 days (40 weeks) from the last menstrual period if the woman has regular 28 day periods. In other words... the embryo is two weeks younger than the number of weeks traditionally assigned to the pregnancy. So, although I am medically considered "5 weeks pregnant" the embryo is only 3 weeks old! To confuse the process even further, not all women ovulate on day 14 of their cycle. I ovulated on day 18 of my cycle with fertilization likely occurring on Christmas day (day 19), which makes the embryo 3 weeks 1 day old. This dates the pregnancy, as a doctor would date it, at 5 weeks 1 day. Clear as mud??? hahaha

Now that you know this, you can understand why I was laughing out loud while watching Meet the Fockers when two of the main characters find the wife is 2 weeks late for her period making her 6 weeks pregnant and decide they can get married in two weeks and tell her father they conceived on the honeymoon. Ummm.... no. The due date would be 6 weeks off which would make it impossible to pull off. An 8 pound, 6 weeks "premature" baby would be a little unbelievable! ;-)

Don't you feel so much smarter now?? hahahaha

I know it is early in pregnancy and I know you can't tell I am pregnant yet (believe me, Aaron told me I am crazy to take pics already). But, I took weekly pics at the beginning of my weight loss journey to document the changes that were occurring in my body and I will be doing the same in pregnancy! I will also be documenting my weight and waist measurements. I have been told I should not gain more than 15 pounds in pregnancy post- bariatric surgery, so we will see how it goes. I am more worried about LOSING too much weight as it will be hard for me to get in 1500 calories a day (1200 for me and 300 extra for pregnancy)!!

Here are the pics!!



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