My son was born prematurely. It was a traumatising time, for me and for my child. To blame the mothers for not doing something or dong something is just unfair. For the record, my son was conceived in the Summer. I did what I was told to do. I ate what I should have, and I had a relatively easy pregnancy. Will just wanted to meet me earlier than expected! .
Infants born preterm may lack key lung cells later in life. Mice born into an oxygen-rich environment respond worse to the flu once fully grown due to an absence of certain lung cells, a discovery that provides a potential explanation for preterm infants' added susceptibility to influenza and other lung diseases later in their lives. Source 3k.
Premature births happen at time for many reasons. I agree with JChampers that no matter what the mother does it still happens. I think science has a ways to go before they figure this out. I will not put any faith into research done on mice in a lab where the conditions have nothing to do with humans. I just hope people understand it will happen at times and other times will not.
Using imaging to identify women at risk of giving birth prematurely. Ultrasound is traditionally used on pregnant women to study the anatomy, movement and blood flow of the developing fetus, but nurse researchers are now using the imaging technique to identify women who are at risk of giving birth prematurely. Source 8r.