No booze during pregnancy the safest option, say Monash developmental scientists

December 19, 2007

No booze during pregnancy the safest option, say Monash developmental scientists

A thirsty nine months is the safest choice for expectant mothers, say senior developmental researchers at the Monash School of Biomedical Sciences.

Research by Professors John Bertram and Richard Harding shows that even moderate levels of alcohol consumption during the third trimester hinders fetal development in organs including the kidney, lungs, brain and blood vessels, and that fetal blood alcohol concentration matches that of the mother.

Their no-booze during pregnancy stance supports the recent NHMRC draft guidelines on alcohol consumption during pregnancy and breast-feeding.

“We don’t really know the full extent of alcohol damage or how little is a safe amount. In view of that, this is a solid recommendation,” says Professor Bertram.

The new guidelines have met with broad approval from scientists, doctors and social workers since their announcement in October. And although some critics claim that they scare-monger women, Professors Bertram and Harding have found widespread alcohol impairment to body functions not measured within the definition of Fetal Alcohol Syndrome.

“We’re concerned about the less obvious effects of alcohol. If you’ve got a child in school who’s not learning properly, who’s got clear facial problems and other symptoms of Fetal Alcohol Syndrome, that’s quite easy to identify. However, it’s the tip of the iceberg. We need to look very hard to find the true extent of these things and what happens with moderate alcohol consumption,” says Professor Bertram.

He and PhD student Stephen Gray presented findings of stalled kidney development at a recent international conference on early human development in Perth.

Their studies found that nephrons – the functional units of the kidney – are especially vulnerable to alcohol damage. The final number of nephrons each person has per kidney is determined by the time of birth.

“The kidneys of fetuses of sheep models exposed to alcohol have about an 11 per cent lower number of nephrons than the control group, and they’re not going to make any more, because the process of making these nephrons has finished,” Professor Bertram said, pointing out that a lower number of nephrons is now thought to correlate with susceptibility to kidney malfunction and disease.

He and Dr Karen Moritz of the University of Queensland recently received a grant that will run between 2008 and 2010 and help them refine their studies of the effect of alcohol on the kidney. They will test the effect of moderate consumption over a 40-day period on the kidneys of animal models.

Their recently presented nephron study formed part of a whole-body experimental program conducted from Prof Harding’s laboratory, which treated sheep models with ethanol to bring blood concentration levels to a 0.1per cent spike every day over a 33-day period.

Unlike most previous studies, which have usually focused on what happens when a consistently high level of intoxication is maintained, researchers at the School of Biomedical Sciences examine the effects of long-term episodic binge-drinking, which resembles a more moderate drinking pattern.

Working with Professor Sandra Rees, a Melbourne University neuroscientist, Prof Harding’s group has uncovered effects in the sensitive white matter of the brain following only a three-day period of drinking. 

“We found that in at least half of the fetal sheep, there was significant white matter injury in the cerebral hemispheres. And we also found injury in the cerebellum which is the part of the brain that’s responsible for control of body movements,” he says.

Meanwhile, Associate Professor Helena Parkington works with the team to focus on blood vessels, and has found stiffening in the walls of blood vessels in fetuses exposed to alcohol - a factor that could contribute to high blood pressure.

Just how much women can drink before they alter the development of their babies may never be tested, due to the variables in each woman’s health situation and the ethical barriers to testing alcohol consumption during pregnancy.

But although we don’t yet know how much will cause damage, we are finding out just how deeply that damage can go.

“It’s proof of principle,” says Prof Bertram.