I had this with my DS, also detected on a scan at 36 weeks (sent by consultant as he suspected I was carrying extra fluid). Diagnosed possible duodenal atresia but the fetal medical consultant wasn’t sure as the scan wasn’t clear due to all the water (I had about 6 times the amount of amniotic fluid you’re supposed to have!)
DS born by emcs a week later after my waters started to leak and at 8 hours old he was taken for an operation. Fortunately it was a jejunal atresia and no other issues, and the operation was quick and successful. He was in NICu and then on a ward for 17 days and then allowed home once he was feeding ok and gaining weight (initially tube fed).
We’ve had some issues with reflux and vomiting when he’s ill, (due to stretched valves etc) but he’s now 11 months and doing really well. No chromosomal abnormalities either but these can be linked to the duodenal atresia, although unlikely If no other markers are spotted.
The week between it being spotted on the scan and DS being born was horrendous. I was also bedridden due to the risk of my waters breaking (risk of cord prolapse), and the hospital stay was obviously stressful too, but in the grand scheme of things, we were lucky and it is usually a relatively straightforward thing for the surgeons to fix.
We transferred care to the John Radcliffe in Oxford, as DC1 had been born there and we knew everything (delivery, postnatal, NICU, children’s hospital) was on one site. They were brilliant.
Hope this has been of some comfort. Try not to google.