Single umbilical artery (SUA)?

K • Mother to a little 🐻... and now one more on the way. Oakland, CA 🌳🌲

Hi all. Just had my 20 week ultrasound and they discovered I have a single umbilical artery (1 artery instead of 2). I have a level II scan next week. I’m also on weekly progesterone (Makena) shots to prevent preterm delivery (my first baby was born at 35 weeks). These combined risk factors are making me a bit nervous... anyone have/had SUA? Thank you 💗