Understanding Low Birth Weight: Concerns and Information

Question
I am concerned about my sisters pregnancy. She is due Dec. 22nd and had an OB appointment today. She is measuring small so they did an ultra sound. They found that the baby boy she is carrying looks to be only 4lbs at full term. His limbs and torso are also measuring too small. Please advise me as to what the problem could be. She is 29 years old, healthy and this is her first pregnancy. She hasn't had any problems with the pregnancy. We do have a first cousin with downs syndrome and are concerned that the baby might be downs? They are enducing her on Monday because of the concerns. I would appreciate any information you could give.

Thank you
Lori Spang

Answer
It is very difficult to measure the estimated fetal weight at 38 weeks gestation. I do not think they believe there is any chromosomal abnormality such as Down's syndrome. It is more likely that she may have some "intrauterine growth restriction" in which the baby may be better off in the nursery rather than in her uterus. That is why they will induce her, if she does not go into labor by Monday.  Don't worry. If there was a reason to push them, they would have delivered her today. Don't worry.