I have no time to read the link, but it caught my attention, as I just returned from the Czech republic. It is a well known fact there, for a while already, and people are advised not to concieve during winter months due to general poor quality of air (which is not only in the biggest cities). It is a world wide phenomenon, just not made very public. We have one of the world's top pre and post natal care and general public does worry about babies and their health a lot, since we don't have many babies being born lately, the population is shrinking too fast.

So, since half of my family are air toxicology specialists and public health risk and enviromental scientists, we have been discussing this theme for ever. I believe the link between air ways problems and time of conception, even if one is in a relatively healthy environment, the air is often bad in small villages as well, due to exhausts, coal burning, etc..I don't remember what other risks there were with winter months conception but could find out.

I don't blame you for your sensitive antenas, hope your little ones breathing improves quickly.