Single artery umbilical cord

Kaely
So I went for a routine appt. at the high risk dr. that my obgyn sends all expectant patients to. I found out that baby's umbilical cord only has one artery instead of two (umbilical cords normally have two arteries and one vein) and that I may potentially be high risk now through the remainder of my pregnancy. Of course I'm nervous, but the dr explained the biggest risk in the pregnancy is that baby may be smaller than average. Has anyone else had this in their pregnancy and what was the outcome? I'm just worried cause I haven't felt the baby too much yet, and now with this I'm extra nervous.