A study from researchers at the University of Bristol and published in the journal Scientific Reports has found that of the 14,500 participants if a girl’s maternal grandmother smoked during pregnancy, the girl is 67% more likely to display certain traits linked to autism (like poor social communication skills and repetitive behaviors).


The study is part of an ongoing, long-term study on the effects of maternal and paternal grandmother’s smoking in pregnancy on the development of their grandchildren, who are all part of Children of the 90s. 1 The team also found that when a maternal grandmother smoked, that increased- by 53% -the risk of her grandchildren having a diagnosed autism spectrum disorder (ASD).

This discovery seems to suggest that if a woman is exposed to cigarette smoke while in the womb, it could affect her developing eggs and cause changes that might eventually affect the development of her own children. Research will now be needed to find out just what those molecular changes are.


Thanks to detailed information, collected over many years on multiple factors that may affect children’s health and development, the researchers were able to rule out other potential explanations for their results.2

Professor Marcus Pembrey, one of the paper’s authors, says:3

“In terms of mechanisms, there are two broad possibilities. There is DNA damage that is transmitted to the grandchildren or there is some adaptive response to the smoking that leaves the grandchild more vulnerable to ASD. We have no explanation for the sex difference, although we have previously found that grand-maternal smoking is associated with different growth patterns in grandsons and granddaughters.

More specifically, we know smoking can damage the DNA of mitochondria — the numerous ‘power-packs’ contained in every cell, and mitochondria are only transmitted to the next generation via the mother’s egg. The initial mitochondrial DNA mutations often have no overt effect in the mother herself, but the impact can increase when transmitted to her own children.”

We’ve known for some time that protecting a baby from tobacco smoke is one of the best things a woman can do to give her child a healthy start in life and now we know that “not smoking during pregnancy could also give their future grandchildren a better start too.”4


Sources and References

  1. Science Daily, April 27, 2017.
  2. Science Daily, April 27, 2017.
  3. Science Daily, April 27, 2017.
  4. Science Daily, April 27, 2017.