Hari, I think you should add another factor to your list: women are not only giving birth later, but having children in a fairly stressed state (because of working full time until the last minute)...and having to return to work sometimes days after delivery. Surely that doesn't help.
Joanna
Hari Kumar wrote:
Says Juriaan: "CDC suggests the 2002 rise in American infant mortality may be a one-time blip, and the US infant mortality rate for 2003 is expected to drop. Previous CDC research suggested the recent rise in infant mortality may reflect the long trend among American women toward delaying motherhood, because:
(1) more women have put off having their first child until their 30s or 40s, at which time they are more likely to have babies with birth defects or other potentially deadly complications;
(2) older women are more likely to use fertility drugs to get pregnant, which often lead to twins, triplets and other multiple births that carry a higher risk of premature labor and low birthweight;
(3) more babies are being born prematurely or at low birthweights, because more doctors are inducing labor and using Caesarean sections for delivery. Multiple births climbed more than 400 percent between 1980 and 1998 because of fertility treatments by older women."
Historically, the strongest underlying etiology of Infant Mortality Rate apparently is the well-being/wealth of a society overall. I would corroborate the CDC view that an increasing proportion of low birth weight (LBW) infants, are from the groups seeking (1) & (2). But the corollary of that is that the survival rates of these infants have been rather dramatically increasing. Even in the most at risk - the <1000 g BW infants. Rather than attribute all to the increase in LBW, I suspect (but have not chased the data as of yet) that more societal factors are at work. Hari