Evolutionary medicine: bottle feeding, birth spacing, and autism

Med Hypotheses. 2011 Sep;77(3):345-6. doi: 10.1016/j.mehy.2011.05.010. Epub 2011 Jun 8.


To compensate for the high metabolic costs of lactation, the likelihood of re-impregnation shortly after childbirth is normally reduced due to hormonal changes triggered by breast feeding during the postpartum period. Nowadays, however, bottle feeding as a substitute for breast feeding precludes such changes and leads to early postpartum reinstatement of fertility. We suggest that recent data showing the risk of autism goes up dramatically as the time between pregnancies goes down [1] may be a byproduct of bottle feeding. The decision to bottle feed your last child may unwittingly put your next child at risk of being autistic.

MeSH terms

  • Autistic Disorder / etiology*
  • Biological Evolution
  • Birth Intervals*
  • Bottle Feeding / adverse effects*
  • Fertility / physiology*
  • Humans
  • Postpartum Period*
  • Risk Factors