12-Week Ultrasound: Understanding Arm Bud Development

Question
Hi!  I just turned 12 weeks and had my first ultrasound today.  The baby has not yet deloved normal arms, hands and fingers.  The person doing the ultrasound called them arm buds.  The baby was moving them quite a bit.  At the time, I didn't think anything of it, because this is my first child.  After, I got home... I read online that babies limbs should be developed by now.  Do you think this is something to worry about?  Any help would be greatly appreciated.  Thank you!  

Answer
Ir is a bit too early to see anything anatomically on a sonogram performed at only 12 weeks gestation. You will have another sonogram around 20 weeks gestation, at which time you will see all the parts of the baby as well as the stomach, heart, legs, and arms.There is nothing to worry about at this time. The limbs are not developed yet in any baby.