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Mums warned of smoking risks while breastfeeding


Breastfeeding warning

Breastfeeding warning

Breastfeeding warning

Irish mums are being warned about the dangers that smoking poses if they are breastfeeding their babies.

New research published today shows that children of mothers who smoke while breastfeeding are more likely to develop serious health problems such as obesity, hypothyroidism, diabetes and cardiovascular disease later in life.

The testing was done on rats - but the results have prompted scientists to call for better information for new mothers on the long-term effects of nicotine exposure on their children.

The study, published in the Journal of Endocrinology, was carried out on rats fitted with nicotine-producing implants to replicate the effect of smoking during breastfeeding.


The rats nursed their offspring as normal and the health of the offspring was monitored into adulthood.

The adult offspring developed obesity and hypothyroidism while rats raised by mothers lacking the nicotine implant remained healthy.

Researchers found that the nicotine exposure caused decreased thyroid hormone levels and resistance to the hormone leptin, which tells us when it's time to stop eating.

The research team was based at the State University of Rio de Janeiro.

The study leader, Dr Patricia Lisboa, said that they have shown that even a small period of nicotine exposure during breastfeeding can permanently damage the future health of a child.

An Irish expert said that she was not surprised at the findings.


Clare Boyle, a midwife and breastfeeding consultant said nicotine is poisonous to the body, which is supported by research.

"Women who smoke while breastfeeding, it affects their milk supply. It decreases the fat content in the milk, it decreases the milk volume and it also decreases the body's ability to let the milk down because it decreases the mothers prolactin levels," she said.

"That will affect the baby's feeding pattern, and the mother might think that they are not producing enough milk, and it could be just related to the fact that they are smoking."