Luriko, I am assuming this is unilateral....because I have had babies w partial bilateral choanal atresia that is very serious.....so hopefully feeding is not compromised here....remember, babies are obbligate nose breathers.....
anyway from an embryologic perspective, this part of the upper palate forms around 4 weeks from cells migrating from the neural crest.....these ectoderm cells move towards the nasal pits that are just beginning to form...so this is one of the places where endoderm (the tube) meets the ectoderm....
this relates to the triple burner and the eight extraordinary vessels.....
Efrem and I have taught about the Donut: "the inside of the inside" and the "outside of the outside" and this part of the nose along with the mouth and anus are key places where they meet....in choanal atresia the membrane that represents their meeting doesnt fully involute leaving a membrane that blocks the back of the nose where it joins the pharynx.....
so we want to activate the natural developmental intention....which is a very "ming" thing to do....
I think along with Efrem's considerations, you might want to consider having mom massage LI 20 with very dilute essential oils you can dilute with olive oil.......several times a day
if we consider when this occurred (first 4 weeks of gestation) then I would consider alternating Du-Ren treatments.....one of the oils I use to activate Du is Cedarwood. very aromatic and jing-stimulating....
and one of the high quality companies I've been using lately that's really good is "young living"....
you can place the dilute oil on the points, and do some tuina vibration on Si3/ B62, lu7/k6
you can also put it in an infuser....
remember, also that choanal atresia can be associated with other congenital abnormalities....heart, developmental, and a multisystem disorder called CHARGE syndrome that I've treated in the past.....so I would def use Grow and Thrive now....
let us know how it works....
steve