Formaldahyde exposure and birth defects

I just wrote about my baby (fetus)'s stomach being small at the 20 and 22 week ultrasounds. I was told this is associated with a possible tracheaoesophageal fistula. I will check back on that question for specifics about that association. However, there is an added element:

I was exposed to formaldehyde during my first trimester (about 2 and a half months along) when we stayed at an Inn that put brand new sheets on our bed without washing them first. My respiration was affected and my hives, which I had been experiencing on and of, were aggravated. I did not find out the cause of my allergic reaction until after 2 nights of sleeping on these toxic sheets. Could formaldehyde exposure contribute to a possible defect such as this fistula?