Quote:
Originally Posted by GREEAR10
My girls first due date was Nov 15th. After going to the OB for the first time they gave her the due date of Nov 19th. When she went in for her 12 week ultrasound they said the baby was small for that age and moved the due date back to Nov 28th.
Why are they allowed to do this? I'm just getting a little iffy because I know stillborn rates go way up the longer a baby is in there. Someone also told me the first due date you get tends to be the most accurate. Not sure how true that is but I have heard it.
I feel like we should be able to ask for her to be induced at this point.
The customary way of estimating a due date is to add 280 days to the first day of the woman's last menstrual period. So if the LMP was 2/10/09, the estimated due date would be today, 11/17/10.
Ultrasound dating is obviously a much better method, so if the first ultrasound calculates a due date more than a few days off from the date calculated by the LMP then we use the ultrasound due date. The later the ultrasound is done, the less accurate it is. But even an ultrasound done at 20 weeks of pregnancy is going to be able to accurately determine gestational age within 10 days.
So we use the first ultrasound to set the final due date if the ultrasound date is more than a few days different from the date calculated from the LMP.
In your case I imagine they gave your girl a due date of 11/19/2010 based on her telling them that the first day of her last menstrual period was 2/12/10. Then when they did an ultrasound the pregnancy measured 10 weeks instead of 12 weeks, so they changed the due date to 11/28. This is going to be accurate within a few days.
I always hear women say things like "they keep changing my due date" or "my doctor thinks i'm due on January 1st but i'm really much farther along" or some such nonsense. The reality is that calculating a due date is very straightforward and simple. We do it exactly one time during pregnancy (at the time of the first ultrasound) and virtually never change the due date after the first ultrasound is done (there are exceptions based on who exactly did the ultrasound.)
The earliest labor can be induced for non-medical reasons is one week before the due date. So she can be induced anytime on or after 11/21.
Irieguy