08-14-2012, 08:32 PM
Join Date: Dec 2010
Re: Ultrasound today! Measuring ahead! Question!
U/S are only considered accurate for dating purposes before 12 weeks, as mentioned. Also, the earlier they are done, the greater the accuracy...so that if one had an U/S at 7 weeks then that is the estimated due date which would be used, even if one subsequently measured ahead at an 11 week U/S. Yours was a bit too late to be taken very seriously, mama, but given that you know when you ovulated, the point is moot for dating purposes. Your midwife will likely keep your original EDD...and if she suggests otherwise, then consider arguing for it. After all, the later your EDD, the lower your odds of being pushed into an unnecessary induction when you might not actually be 42 weeks yet, KWIM?
With the NT test, the normal range of up to 3 mm is the same whether you're 12 weeks or 13 weeks and 6 days; it's in the earlier 11-12 week that a lower range up to 2 mm would be considered normal. So your results are unlikely to differ based on a longer crown-to-rump length. Ask the midwife for the actual NT number, if it's more reassuring to you.
And of course...the IPS is not a diagnostic test. It provides the odds of different possibilities only, not the definite genetic condition of your baby.
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