Researchers from the Norwegian University of Science and Technology claim the health of a child is determined in the womb.
They found no evidence that breastfeeding reduced the risk of developing allergies and asthma, as previous studies have suggested, and that it brought only a slight benefit to children's IQ.
The study also found a link between the level of male hormones in pregnant women and how much they breastfed after birth.
The researchers followed 180 pregnant women, including those at risk of delivering a small baby, which is known to be influenced by higher levels of the male hormone testosterone. They also reviewed more than 50 international studies on the relationship between breastfeeding and health.
Breastfeeding levels were lower in women who had more testosterone in their bodies when they were pregnant, including young mothers, and those who smoke, are overweight, have hormonal disorders or were having a boy. Their ability to produce milk was reduced.
However, the older a mother was, the more likely she was to breastfeed due to lower levels of the male hormone in the womb.
Lead researcher Professor Sven Carlsen said, 'There are many good reasons to breastfeed. But concern for the child's health is not one of them. There is no reason why women who are struggling to breastfeed should have to go around feeling guilty, or think that they are giving their child a poor start in life if they can't nurse. Baby formula is as good as breast milk.'
He said the strongest reason to encourage mothers to breastfeed is to cut the environmental costs of producing bottles and formula and using energy to sterilise bottles.
The UK Department of Health advises that babies should be breastfed for the first six months.
A spokesperson said, 'The Government recognises that breastfeeding is the best form of nutrition for infants. It gives health benefits for both the baby and the mother even after they are no longer breastfeeding. It protects against stomach bugs and chest infections, provides perfect nutrition for the first six months, and reduces the likelihood of becoming obese in later childhood.
'Our advice is based on World Health Organisation guidance, which recommends exclusive breastfeeding in its report Optimal duration of exclusive breastfeeding, and this is backed up by the Scientific Advisory Committee on Nutrition in this country.'
FURTHER INFORMATION
The research is published in this month's 'Journal Acta Obstestricia and Gynecologia Scandinavica'.
