Neural Tube Defects

I recently had my second trimester genetic lab testing done. My doctor called today stating that the results say my baby could be at risk for neural tube defects. I have not yet had my 2nd ultrasound (scheduled for this week). She is scheduling me for a more in depth ultrasound and also having me see a specialist early next week. Has anyone else been in this situation...if so what was the outcome? My doctor said not to worry, that she is only doing everything as a precaution, and believes everything will be fine.