How accurate are ultrasounds at 20 week?

[concernedmommy160]

My doctor changed my due date at my 20 week ultrasound from 8/21/12 to 9/3/12 and I am very regular with my menstral cycles and feel like I am further along than the ultrasound due date and keep having contraction and they keep stopping my labor. This is my fifth pregnancy and I have little babies. Do you think I should talk to my doctor about this and explain to her that I think the ultrasound is wrong I am also worried because I have been on hydrocodone due to chronic pain been off for a week now and don't want my baby to have withdraws.

[Mom2amiracle2012]

The ultrasound in the beginning is a good indicator of conception. But it is just an estimate. I showed just a fetal pole for weeks without a heartbeat. It changed my conception date by three weeks. I knew when I conceived though. It was the last time we had sex. None of that matters though. The baby will come in its own time.

[concernedmommy160]

I am going to talk to my doctor at my appointment tomorrow I just wanted to get some opinions until then.

[Clysta]

Ultrasounds are more accurate in the first trimester, but that isn't the only time they're accurate. I agree, talk to your doctor. She's the one who will be able to work with you on this.

[Morrisfamily2012]

i'm not sure. i've always thought first trimester ultrasounds were the most accurate for dating. at the 20 week scan though organs and measurements shouldn't be off by more than a week or 2. i would talk to your doctor about how you feel. your doctor knows best, even if you don't trust him 100% maybe you could get a second opinion.

[concernedmommy160]

They have already stopped my labor twice. Once at 30 weeks by the ultrasound and once four days ago. I have readasounds were only accurate in the first trimester but you can't believe everything you read.

[Mom2amiracle2012]

The 20 week ultrasound is the most accurate thus far but you might be able to ask for further monitoring via ultrasound. That may help ease your nerves. But seeing you have other babies, you know your body best. Watch out for signs of labor.