Sunday, October 03, 2010

Are some Irish mothers "too posh to push"?

The use of C-section to deliver babies has tended to go up over time and has generated some concern. It is, after all, a significant operation and can have negative consequences. For example mothers are less likely to breastfeed after a C-section.

It is sometimes argued that mothers elect to have C-sections as they are “too posh to push”. Leaving aside the question of whether this is a good or bad thing: is it actually true? Using the Growing Up in Ireland data I estimate some simple probit models predicting the probability of elective and emergency c-sections. Household income (equivalised & in log form) is positively associated with having a C-section. But the coefficient for emergency c-section is almost twice as big as that of elective. This doesn’t fit in with a simple story of affluent mothers choosing to have c-section. I have no idea why income would have such an effect on emergency C-sections.

Mother’s education, interestingly, seems to have no effect (& remember education is generally seen as a better measure of socio-economic status than income) nor does a measure of social class (not shown here) nor does whether the mother smoke or drank during pregnancy. Factors that do predict a c-section include the mother’s BMI and her age (for the elective case) and the baby’s birth-weight (for the emergency case). Clearly many other factors may influence these outcomes & not all of which are in this data.

So while there is clearly a connection between how well-off a mother is and whether she delivers via a C-section its not at all clear that it is a simple case of "money talks".





log income





mother's educ










born on time





" early





" very early















Mothers BMI





" smoke





" drink













pseudo R2



Marginal effects; Absolute t statistics in parentheses

* p<0.05,**p<.01,***p<.001


Peter Carney said...

"I have no idea why income would have such an effect on emergency C-sections."

Kevin, interesting post. one reason for the income finding might just be family size.

If you have one birth by c-section then subsequent births will be by c-section in the vast majority (~90%) of cases. So one idea is that maybe what you're finding here is that poorer mums are having relatively more routine c-sections (i.e., relatively fewer emergency c-sections) than richer mums cause they are having more children than richer mums.

Another, less probable reason, is that some mums may have a preference for the 'au natural' birth but then elect for c-section in the 11th hour. it might be reasonably, if you accept the hypothesis, that it's easier for richer mum's to switch due to insurance. If the c-section is not scheduled, it would probably fit the emergency box best.

so, if you could control for birth-order or family-size, and pmi status, i would wager you'll explain the odd finding on income; notwithstanding the education finding.

Kevin Denny said...

I am not sure about that argument but maybe, I will check if I have family size in the data.
If a mother decides late in pregnancy that she wants a C-section I would have thought that would still be an elective- an emergency one has to be decided for medical reasons?