Twenty eight yr old lady, G4 P2+0 L1 with POG 13+2 wk with history of tracheooesophageal fistula in previous two babies( operated after birth,first one died on day 3,second was also operated,alive and well now) presented to us.There is no history of derranged blood sugars in any previous pregnacy, GTT normal in present pregnancy also.NT/NB scan,double marker ,all routine investigations normal. No history of preconceptional folic acid uptake.What more can be offered?
What may be the cause?