I'm concerned about my sonogram results. First, I discovered my unborn baby is breech and second that her measurements don't match. I am 32 weeks pregnant and the baby's femur measures 32 weeks, but the head measures 35 weeks! Is this cause for concern?
The head measuring larger than the femur is usually normal. In fact, toward the end of the pregnancy, the head measurement indicating gestational age becomes less reliable. The femur length pretty much stays accurate, though. The head measurement can easily be off by as much as three weeks in late pregnancy.
What would be a cause for concern is if all your baby's measurements are weeks behind. For example, if her femur and head measured at 28 weeks and you are 32 weeks along. This condition, called "Small for Gestational Age" (SGA) often leads to a higher incidence of fetal distress, stillbirth, and childhood problems. There can be several reasons why an unborn baby is SGA.