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Alcohol and breastfeeding

Alcohol and breastfeeding

September 10 2013

What does research tell us?

Dr Tanya Cassidy won a Health Research Board Cochrane Fellowship to examine this important issue and in particular to investigate ways that might reduce alcohol consumption during breastfeeding.

It’s a complex area’, insists Cassidy.  ‘Research on the effects of alcohol has to take account of a multitude of factors, such as: how much alcohol is consumed; the mother’s pattern of drinking; the time interval between ingestion and nursing; and the age of the infant.

The baby’s age is a key concern, as even small amounts of alcohol can have a greater effect on younger infants. We know too that what a mother eats and drinks affects the taste of her milk and that alcohol produces odour and flavour changes of the milk which can lead to heightened nursing concerns.

Higher levels of alcohol consumption are associated with difficulties with the ‘let-down’ reflex. The let-down reflex,  also called the milk ejection reflex, is set off by the hormone oxytocin. It stimulates the muscle cells in breasts to squeeze out milk. Alcohol impairs this process. 

A Taiwanese study found that women who consumed chicken soup flavoured with rice wine experienced a significantly longer time regarding milk ejection. These biological delays regarding the release and volume of milk can have direct effects on infants, and can lead to decisions to introduce formula feeding, but more research is needed in this area.’

There is a considerable amount of research available which shows that health outcomes, including infectious morbidity,  childhood obesity, type 1 and type 2 diabetes, leukaemia, and sudden infant death syndrome, are substantially different among mothers and infants who formula feed compared with those who breastfeed.

‘Not surprisingly, mothers and expectant mothers are understandably eager to receive guidance and informed advice from their healthcare advisors and providers about breastfeeding ‘do’s and don’ts’,  she continues. ‘Alcohol consumption among mothers following birth is one such topic and it has fuelled its fair share of controversy.

In the western world, the consensus advice suggests that abstinence during breastfeeding offers the best health outcomes. However,  when we look at what women of child rearing age actually do across the world,  anthropologists and other researchers have found that alcohol consumption in child-bearing women appears to be the cultural norm’, says Cassidy.

‘In the United States, alcohol consumption rates for women of child-bearing age are over 50%. Public Health Canada reports that roughly 75% of women of child-bearing age reported using alcohol in previous 12 months. In Australia, over half of adult women under fifty reported consuming alcohol on a weekly basis and almost a third had consumed alcohol on a daily basis.

In Ireland a study of women who attended the Coombe Women’s Hospital found that almost two-thirds (63%) of the 43,318 women surveyed said they drank alcohol during their pregnancy. The situation is put into stark relief when the number of women who stopped drinking during pregnancy 13.2% is contrasted with the almost 50% who gave up smoking.

It is not insignificant that Ireland has one of the highest rates of alcohol consumption in Europe, and one of the lowest breastfeeding rates. Somewhat encouragingly, though, the national breastfeeding survey showed that only a small number of women stated explicitly that they stopped breastfeeding in order to be able to drink alcohol. In Northern Ireland, however, similar research found that some of the mothers they interviewed never started to breastfeed, so that they might accommodate a drinking lifestyle.

Interestingly, separate research has demonstrated that women who consume alcohol during lactation are not necessarily women considered by health professionals to be at high risk of alcohol intake. The Norwegian, New Zealand and Australian data all indicate an association between alcohol intake during lactation and a higher level of education and household income. Women with a higher education level and income are the women most likely to breastfeed, but these also seem to be women who are more likely to consume alcohol daily, having direct effects on their breastfeeding’.

Dr Cassidy continues, ‘A Cochrane review involves looking at all of the peer-reviewed evidence on a topic, assessing it for quality against strict criteria, then aggregating the findings in order to come up with the best evidenced-based conclusions. My co-author in the review is Dr. Roslyn Giglia from Curtin University in Perth, Australia.

In Australia, the Government has issued recommendations that nursing mothers should avoid alcohol consumption completely until after the baby is one month old.  They also recommend not consuming alcohol shortly before feeding; if women are to drink, not to consume more than two units per day; and not to drink every day. It’s a balancing act that addresses the reality that a lot of women in the modern world are in fact social drinkers. If you tell mothers not to drink at all it might discourage them from breastfeeding in the first place, or it may influence a decision to end breastfeeding early.  The advice recognises that breastfeeding rates are generally low and that on a population level there are societal benefits if more babies are breastfed for longer than is currently the case.

As we worked our way through the available data, it was clear that many studies mention the issue of alcohol and breastfeeding as an extension of pregnancy. There has been limited work on alcohol and breastfeeding specifically. This is not surprising given the complexity of the issue, never mind the social and cultural barriers around the accuracy of self-reported alcohol consumption, and the inherent pressures on any mother to play down her level of alcohol consumption in order to meet perceived cultural expectations.

We found a particularly interesting example of a randomized control trial concerning alcohol and breastfeeding, the American ‘Healthy Moms’ study. This study identified high-risk alcohol-consuming women and randomly assigned them to receive a brief educational intervention from their healthcare provider or not and found, through longitudinal interviews,  that the group receiving the intervention were substantially more likely to reduce their alcohol consumption. Another American study argues that digital intervention is also useful, but did not concentrate on breastfeeding mothers.

We hope to publish the full results of our analysis before the end of the year.  As with all Cochrane reviews, this will be available from the Cochrane Library,  which everyone from the island of Ireland can access for free. This arrangement is sponsored by the HRB and its Northern Ireland equivalent’.

Dr Tanya Cassidy is a Medical Sociologist affiliated with the Anthropology Department at NUI Maynooth. Dr Cassidy has extensive expertise in researching alcohol and gender related issues.


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