Wow. This coming month’s Pediatrics seems to have been written specially for this blog. The magazine is a treasure trove of studies about hot parenting topics, but the editorial staff seems to have outdone themselves this time. Let’s see:
In the “Yet another nail in the coffin” dept. we have an Italian study of over 1400 children, Tozzi et al, which demonstrated that the amount of thimerosal given to children in their pertussis vaccines (the children were randomly assigned to receive low or high-dose thinerosal, 62.5 vs. 137.5 mcg) made no difference in most (22/24) test of neuropsychological performance they were given 10 years later. In the two tests the high-thimerosal group did differ on (in girls only, the finger-tapping test and the Boston Naming test), though the difference was statistically significant, the absolute score difference between the two groups was low, and as the researchers point out, so many tests were given that it could very well be a matter of chance that some of the results came out statistically significant.
Keep in mind that this is not, per se, a refutation of the thimerosal/autism theory, but rather a corroboration of Thompson et al (2007), which also examined the purported link between thimerosal exposure and later neuropsychological outcomes…with very similar results. There was one child with autism…in the lower-dose group.
In the “Somebody desperately needs a shave with Occam’s Razor” dept. we’ve got Strathearn et al, which followed up an Australian cohort of prospective mothers presenting themselves for prenatal care at a large maternity hospital in Brisbane in 1981-84. Of the original 7223 maternity patients with liveborn, singleton babies delivered at the hospital, 92% (6621) of the mother-infant dyads were available for followup at 6 months with regard to breastfeeding info, various sociodemographic factors and government agency reports of child maltreatment if present. At 15 years later, records were collected on 81.5% of the original qualifying cohort (5890 dyads) with regard to later maltreatment. 512 of the children were reported to the authorities with at least one maltreatment episode (either neglect, emotional abuse, physical abuse, or a combination of same).
After adjusting for a veritable mountain of confounding factors (the table listing these variables takes a page and half of the article and covered age, marital status, substance abuse, whether the pregnancy was wanted and many other factors), the researchers found that the mothers who didn’t breastfeed had 2.6 times the odds (95% CI 1.7-3.9) for maltreating their children in any way as compared to mothers who breastfed 4 or more months. Of the various types of maltreatment, only child neglect was independently associated with breastfeeding duration, though all types of maternal maltreatment were associated with significantly lower incidence when not adjusted for other maltreatment types (in case more than one type of maltreatment occurred).
The authors’ conclusion? Breastfeeding (or rather, the oxytocin secreted from the mother’s pituitary while breastfeeding) prevents a child from being maltreated by her mother. Groan.
Let’s think about this for a minute: If one were the type of woman prone to abusing – or especially neglecting – one’s baby, what kind of feeding method would best enable Mom to pop out for a party overnight, or allow her to pursue her addictions with the minimum of hassle? Would such a woman be up to dealing with sore nipples, engorgement or low supply issues? What feeding method would she be likely to choose?
I wouldn’t say no such women would breastfeed, but it seems logical that many such women would not bother to, or quit at the first sign of trouble or inconvenience. In fact, a previous study (which the authors of the present one mention in the discussion, to their credit) demonstrates that breastfeeding doesn’t enhance maternal sensitivity and infant attachment; rather, the intent to breastfeed and subsequent infant attachment are both caused by the mother’s quality of sensitivity. Similarly, it makes sense that whatever quality (hormonal or otherwise) makes women want to breastfeed also prevents women from maltreating their children. Intent to breastfeed before giving birth, however, was not assessed in this cohort.
Does this study mean that if women at high risk of abusing their children are pressured to breastfeed, they’ll be less likely to maltreat their children? No, but it’s probably worth further study (you could also correlate national breastfeeding rates, which have risen in all socioeconomic strata since the early 80s, to the national rates of maternal child abuse, to help answer this question). Will Jane in Suburbia be more likely to abuse or neglect her children as a result of the fact that she bottle feeds? Not bloody likely.
(Kudos to Annie for not entirely falling for this one, BTW. The title of her post could use some work though, IMHO).
And finally, in the “Makes you go Hmmm…” dept. we’ve got Shapiro-Mendoza et al. The authors, on behalf of the CDC, looked at the national infant mortality rates between the years 1984-2004, sorted according to cause of death. They found that there was a dramatic decrease in total causes of SUDI (sudden unexpected infant death) and SIDS during the early 90s as a result of the “back to sleep” campaign. More importantly,despite there being fairly stable rates of SUDI in the years after the campaign’s effect (1996-2004), there was a marked downward shift in SIDS rates, corresponding to an increase in deaths due to accidental suffocation and “unknown”. This strongly suggests that a diagnostic shift is occurring – namely, many deaths that would have been attributed to SIDS in past years are now thought to actually have been caused by suffocation.
The researchers examined the death certificates of accidental suffocation deaths from the years 2003-2004. Too many details were missing in too many certificates to come to a definite conclusion, but the information which can be gleaned, especially combined with prior knowledge about accidental suffocation (e.g. the CPSC’s Drago and Dannenberg) suggests a role for bedsharing as a cause of at least some of the deaths. A majority (51.2% of death certificates) of the infants were bedsharing at the time of death; the most common known cause (33.8% of death certificates) of death was by overlaying, which could not happen in a crib; and the largest known category of deaths occurred in adult beds (27.5%).
Most of the suffocated infants died in the first 3 months of life, which corresponds to the known additional risk for SIDS/SUDI seen in bedsharing infants, even in the absence of smoking as a risk factor.
Dr Amy disagrees; we’re having an interesting exchange in the comments of her blogpost.