I'm not sure, but I do know that being delivered the old-fashioned way somehow helps you to start breathing air (as opposed to the amniotic fluid you've been breathing for nine months).

There is some speculation over at ICAN-online.org about this finding, but no one really knows for sure. It might have to do with anesthetics, with fetal/maternal stress caused by surgery, or with (as my pediatric nurse MIL thinks) the fact that many c/secs are done earlier than 40 wks. Baby lungs generally do better the longer the baby is in the womb.

In the rest of the original article (through the BBC I think), it mentions that the stats above don't include stillbirths. If stillbirths are included, the difference disappears. The breathing problems associated with c-section babies are still under research--I agree with Marie and emjaybee that what I've heard relates to lung development and the stress of vaginal birth helping the baby clear the lungs of amniotic fluid.

i'm skeptical. before i'd wag my finger at these c-section women, i'd make sure their risk was not just "low", but exactly equal to that of the vaginal delivery women. i doubt that it was -- nyt lifestyle articles aside, very few women have c-sections for fun.

as for the biology, i'm not an expert in this exact field, but based on science i've seen in mouse brains, it's possible that the hypoxia (lack of oxygen) involved in vaginal birth may have (positive) effects even at the cellular level, turning on genes babies need outside the womb.

From my reading of the Birth article at http://www.blackwell-synergy.com/doi/full/10.1111/j.1523-536X.2006.00102.x?cookieSet=1 , I would point out that most of the neonates died from congenital abnormalities. There may very well have been prebirth diagnosis and a decision to section because of it, that the data set doesn't include. Although the researchers tried to screen out all at-risk pregnancies, the data set may not have been accurate, and the section group might just have been at higher risk.

There isn't any finger wagging at mothers on the part of the authors, though. And keep in mind, although the risk is higher with section, it's going from less than 1 per 1,000 live births, to less than 2 per 1,000 live births.

There are some issues--as always--with the paper. The main question which is being debated is whether or not the comparisons of the groups was correctly done.

In simplified terms: The paper is trying to analyze how many deaths WOULD HAVE OCCURED in the C section group had the C sections not occured.

Then, you can look at the number of deaths which actually DID occur, and see if it is larger, and if so, by how much. It is the DIFFERENCE in death rates which explains the "added" risk of section, so the DIFFERENCE is the most relevant.

The problem with the paper is very simple: Although there are an increasing number of "social" c sections, the primary cause for a section remains medical. In other words, someone thought (rightly or not) that something was "going wrong".

The vaginal delivery group was ultra low risk--one of the lowest neonatal death rates ever recorded over such a large group. Thus, any enhanced risk in the C section group would have produced an artificial difference: It could seem that the sections were more dangerous, but the real explanation could be that the section group was simply higher risk and would have expected more deaths. I.e., the increase in deaths may not be attributable to sections.

The main problem stems from the categorization using birth certificates. These are known to be fairly unreliable.