Fish during pregnancy, passing mental health down the generations, and… peak cuteness of puppies – here are the highlights from baby science from May.
Autism not linked to eating fish during pregnancy
A major study carried out by researchers at the University of Bristol has concluded that pregnant mothers who eat fish during pregnancy do not increase the risk of autism in their children. There were fears that eating fish may raise the levels of mercury in the blood, which may affect foetal brain development. However, studying the diet and blood samples of over 4,500 mothers enrolled in the ‘Children of the 90s’ study revealed that neither the level of mercury in the blood, nor fish consumption, were linked to autism. The researchers conclude that the nutritional benefits of fish outweigh any potential harm from mercury, and are now calling for simpler healthy eating messages to make that clear to pregnant women.
Research published in Molecular Autism.
Men may pass on the effects of early life trauma through their sperm
Researchers based at Tufts University in Boston have identified that traumatic events in a man’s childhood may leave genetic traces in his sperm, which could be passed onto his children. In a small study of nearly 30 men, they showed that men who experienced abuse or neglect as a child have vastly reduced amounts of specific “microRNAS” in their sperm. Individual microRNAs are able to control the activity of a specific set of genes.
The researchers also showed that the very same microRNAs that are reduced in the men are also reduced in stressed male mice, and in their male offspring. Previous research in mice exposed to early life stress shows that their offspring display signs of anxiety.
Children whose fathers were exposed to abuse and neglect as a child are more likely to experience poor physical and mental health in their own lives. Though more work is needed, this research suggests that the effects of stress passed down to children may in part be mediated through microRNAs in sperm affecting specific genes during embryo development – and suggests the potential to break this trans-generational link.
Research published in Translational Psychiatry.
Health of placenta may be key link between genetics and risk of schizophrenia
Scientists have long known a person’s risk of developing the mental health condition schizophrenia can be influenced both by the genes that they carry, but also by whether their mothers experienced complications during their pregnancy. Now new research has discovered that the placenta may be the common link between the two. Studying over 2,000 people with the disorder, scientists at the Lieber Institute for Brain Development in Baltimore have shown that the genes linked to schizophrenia are activated in placentas from complicated pregnancies. They found that people with the highest genetic risk and whose mothers had a complicated pregnancy were five times more likely to develop schizophrenia, compared to people who had the same high genetic risk but who were from normal pregnancies. Despite its importance in pregnancy, the placenta is not well understood as an organ, and this research reveals a previously unappreciated role for the placenta in disorders like schizophrenia.
Research published in Nature Medicine.
Mothers’ voices get lower after giving birth
Researchers based at University of Sussex have demonstrated that the pitch of a woman’s voice dips significantly after giving birth – a phenomenon that has been noticed by popstar Adele. The researchers studied voice recordings from 20 new mums up to 5 years before and after giving birth, and compared them to 20 women who had never given birth. They found that a new mum’s voice gets lower by about a semitone (one piano key’s difference), and becomes more monotonous. This ‘masculinised’ voice is only temporary, however, as mothers regain their normal pitch by about a year after birth. As people with low-pitched voices are typically judged (rightly or wrongly) to be more competent, mature, and dominant, the next step in the research is to understand whether the change of voice in new mums affects how others perceive them.
Research published in Evolution & Human Behaviour.
And finally…. optimum age for cuteness of puppies revealed
We can all sleep tight, pupper – researchers based at Arizona State University have identified the age at which puppies are at their most cute. 51 (human) participants were asked to rate photos of puppies at different ages for cuteness. The age for ‘peak cuteness’ was discovered to be somewhere between 6 and 8 weeks old – which happens to be around the age at which puppies are weaned from their mothers, depending on the breed. “Around seven or eight weeks of age, just as their mother is getting sick of them and is going to kick them out of the den and they’re going to have to make their own way in life, at that age, that is exactly when they are most attractive to human beings,” said Prof Clive Wynne, who led the research. This study reveals how dogs have adapted to ensure a strong enduring bond with humans, an interaction which has been essential for their survival for thousands of years.
What has this got to do with human babies? Absolutely nothing – just an excuse to post photos of puppies.
Research published in Anthrozoös.