Our thanks to Dr Eran Elhaik, a lecturer at Sheffield University, for pointing us to his recently-published paper, Adversarial childhood events are associated with Sudden Infant Death Syndrome (SIDS): an ecological study.
The full Abstract:
Sudden Infant Death Syndrome (SIDS) is the most common cause of postneonatal infant death. The allostatic load hypothesis posits that SIDS is the result of perinatal cumulative painful, stressful, or traumatic exposures that tax neonatal regulatory systems. To test it, we explored the relationships between SIDS and two common stressors, male neonatal circumcision (MNC) and prematurity, using latitudinal data from 15 countries and over 40 US states during the years 1999-2016. We used linear regression analyses and likelihood ratio tests to calculate the association between SIDS and the stressors. SIDS prevalence was significantly and positively correlated with MNC and prematurity rates. MNC explained 14.2% of the variability of SIDS’s male bias in the US, reminiscent of the Jewish myth of Lilith, the killer of infant males. [J4MB emphasis] Combined, the stressors increased the likelihood of SIDS. Ecological analyses are useful to generate hypotheses but cannot provide strong evidence of causality. Biological plausibility is provided by a growing body of experimental and clinical evidence linking adversary preterm and early-life events with SIDS. Together with historical evidence, our findings emphasize the necessity of cohort studies that consider these environmental stressors with the aim of improving the identification of at-risk infants and reducing infant mortality.
The full section, “Implications of our findings” (pp.10,11), emphases ours:
Our findings suggest that MNC, the most common unnecessary surgery in the world, is a major risk-factor for SIDS. Circumcised infants living in a stress-fraught environment, born prematurely, or have an existing genetic predisposition to sudden death would be at the highest risk of SIDS. While the risks of preterm births are well recognized, the debate concerning MNC is polarized between ethical concerns  and financial motives [100, 101] clouded by alleged medical benefits, with little awareness of the long-term risks for infants. Although the conclusions of our ecological study should be verified in a cohort study with properly matched infants , some recommendation can be implemented immediately at little cost, such as: eliminating neonatal circumcisions when possible, postponing non-medical circumcisions to later ages, informing parents of the risks in MNC, and applying pain management techniques to neonates that experience repetitive pain. MNC data should also be collected and tested in prospective SIDS studies.