Posts tagged womb
Articles and news from the latest research reports.
Fetus in womb learns language cues before birth, study finds
Watch your mouth around your unborn child – he or she could be listening in. Babies can pick up language skills while they’re still in the womb, Finnish researchers say.
Fetuses exposed to fake words after week 29 in utero were able to distinguish them after being born, according to new research in the Proceedings of the National Academy of Sciences.
"Prenatal experiences have a remarkable influence on the brain’s auditory discrimination accuracy, which may support, for example, language acquisition during infancy," the authors wrote in their study.
As revealed by the allure of the so-called Mozart Effect – the idea that exposing the fetus to classical music earns kids extra IQ points in spatial reasoning down the line – parents are constantly looking for ways to give their children an intelligence advantage.
That’s even if the research their parenting tactics are based on is too narrow to draw such broad conclusions or remains under question (the Mozart Effect was deemed "crap," for example, by one scientist.)
Nonetheless, scientists have discovered plenty of evidence that what’s heard in utero can make a lasting impression. Fetuses respond differently to native and nonnative vowels, and newborns cry with their native language prosody (a combination of rhythm, stress and intonation). Researchers led by Eino Partanen at the University of Helsinki wanted to see what other language cues a fetus might pick up in the womb.
For the experiment, Finnish mothers were asked to play a CD with a pair of four-minute tracks that held music punctuated by a fake word: tatata. On occasion, they changed up the vowel – tatota – and in other instances they switched the pitch – tatata, when the middle syllable could be 8% higher or lower, or 15% higher or lower. The false word and its variants featured hundreds of times as the tracks played, and the mothers were asked to play the CD five to seven times per week.
Then, after several weeks of exposure to the fake word, the researchers had to determine whether all this in-utero training had somehow stuck.
The researchers were relying on a phenomenon called mismatch response: a flash of neural activity when the brain picks up on something off, something not quite right – such as when the word tatata is suddenly tatota. If that flash goes off, it means that something doesn’t make sense compared to what the brain has already learned.
The scientists figured that if the flash went off the first time the infant babies heard the modified words (tatota or tatata) after being born, it would mean that they’d been paying attention while in the womb.
They tested the mismatch response once the babies were born by attaching electrodes and studying their brain activity.
Sure enough, the newborns that had been trained in the womb had a response roughly four times stronger to the pitch change (tatota versus tatata) than untrained newborns. (Both trained and untrained babies picked up the tatata versus tatota vowel distinction.)
The findings could mean it’s possible to give babies a little language leg-up before they ever say a word — particularly the children who may need it most.
"It might be possible to support early auditory development and potentially compensate for difficulties of genetic nature, such as language impairment or dyslexia," the authors wrote.
But, the scientists point out, it could mean that babies are also vulnerable to harmful acoustic effects – “abnormal, unstructured, and novel sound stimulation” – an idea that will also require further study. Until then, perhaps it’s best not to hang around any noisy construction sites while pregnant.
Foetal exposure to excessive stress hormones in the womb linked to adult mood disorders
Exposure of the developing foetus to excessive levels of stress hormones in the womb can cause mood disorders in later life and now, for the first time, researchers have found a mechanism that may underpin this process, according to research presented today (Sunday) at the British Neuroscience Association Festival of Neuroscience (BNA2013) in London.
The concept of foetal programming of adult disease, whereby the environment experienced in the womb can have profound long-lasting consequences on health and risk of disease in later life, is well known; however, the process that drives this is unclear. Professor Megan Holmes, a neuroendocrinologist from the University of Edinburgh/British Heart Foundation Centre for Cardiovascular Science in Scotland (UK), will say: “During our research we have identified the enzyme 11ß-HSD2 which we believe plays a key role in the process of foetal programming.”
Adverse environments experienced while in the womb, such as in cases of stress, bereavement or abuse, will increase levels of glucocorticoids in the mother, which may harm the growing baby. Glucocorticoids are naturally produced hormones and they are also known as stress hormones because of their role in the stress response.
“The stress hormone cortisol may be a key factor in programming the foetus, baby or child to be at risk of disease in later life. Cortisol causes reduced growth and modifies the timing of tissue development as well as having long lasting effects on gene expression,” she will say.
Prof Holmes will describe how her research has identified an enzyme called 11ß-HSD2 (11beta-hydroxysteroid dehydrogenase type 2) that breaks down the stress hormone cortisol to an inactive form, before it can cause any harm to the developing foetus. The enzyme 11ß-HSD2 is present in the placenta and the developing foetal brain where it is thought to act as a shield to protect against the harmful actions of cortisol.
Prof Holmes and her colleagues developed genetically modified mice that lacked 11ß-HSD2 in order to determine the role of the enzyme in the placenta and foetal brain. “In mice lacking the enzyme 11ß-HSD2, foetuses were exposed to high levels of stress hormones and, as a consequence, these mice exhibited reduced foetal growth and went on to show programmed mood disorders in later life. We also found that the placentas from these mice were smaller and did not transport nutrients efficiently across to the developing foetus. This too could contribute to the harmful consequences of increased stress hormone exposure on the foetus and suggests that the placental 11ß-HSD2 shield is the most important barrier.
“However, preliminary new data show that with the loss of the 11ß-HSD2 protective barrier solely in the brain, programming of the developing foetus still occurs, and, therefore, this raises questions about how dominant a role is played by the placental 11ß-HSD2 barrier. This research is currently ongoing and we cannot draw any firm conclusions yet.
“Determining the exact molecular and cellular mechanisms that drive foetal programming will help us identify potential therapeutic targets that can be used to reverse the deleterious consequences on mood disorders. In the future, we hope to explore the potential of these targets in studies in humans,” she will say.
Prof Holmes hopes that her research will make healthcare workers more aware of the fact that children exposed to an adverse environment, be it abuse, malnutrition, or bereavement, are at an increased risk of mood disorders in later life and the children should be carefully monitored and supported to prevent this from happening.
In addition, the potential effects of excessive levels of stress hormones on the developing foetus are also of relevance to individuals involved in antenatal care. Within the past 20 years, the majority of women at risk of premature delivery have been given synthetic glucocorticoids to accelerate foetal lung development to allow the premature babies to survive early birth.
“While this glucocorticoid treatment is essential, the dose, number of treatments and the drug used, have to be carefully monitored to ensure that the minimum effective therapy is used, as it may set the stage for effects later in the child’s life,” Prof Holmes will say.
Puberty is another sensitive time of development and stress experienced at this time can also be involved in programming adult mood disorders. Prof Holmes and her colleagues have found evidence from imaging studies in rats that stress in early teenage years could affect mood and emotional behaviour via changes in the brain’s neural networks associated with emotional processing.
The researchers used fMRI (Functional Magnetic Resonance Imaging) to see which pathways in the brain were affected when stressed, peripubertal rats responded to a specific learned task.
Prof Holmes will say: “We showed that in stressed ‘teenage’ rats, the part of the brain region involved in emotion and fear (known as amygdala) was activated in an exaggerated fashion when compared to controls. The results from this study clearly showed that altered emotional processing occurs in the amygdala in response to stress during this crucial period of development.”
(Image: iStockphoto)
Newborn memories of the “oohs” and “ahs” heard in the womb
Newborns are much more attuned to the sounds of their native language than first thought. In fact, these linguistic whizzes can up pick on distinctive sounds of their mother tongue while in utero, a new study has concluded.
Research led by Christine Moon, a professor of psychology at Pacific Lutheran University, shows that infants, only hours old showed marked interest for the vowels of a language that was not their mother tongue.
"We have known for over 30 years that we begin learning prenatally about voices by listening to the sound of our mother talking," Moon said. "This is the first study that shows we learn about the particular speech sounds of our mother’s language before we are born."
Before the study, the general consensus was that infants learned about the small parts of speech, the vowels and the consonants, postnatally. Moon added. “This study moves the measurable result of experience with individual speech sounds from six months of age to before birth,” she said. The findings were published in Acta Paediatrica.
Fetal healing: Curing congenital diseases in the womb
Our time in the womb is one of the most vulnerable periods of our existence. Pregnant women are warned to steer clear of certain foods and alcohol, and doctors refrain from medical interventions unless absolutely necessary, to avoid the faintest risk of causing birth defects.
Yet it is this very stage that is now being considered for some of the most daring and radical medical procedures yet devised: stem cell and gene therapies. “It’s really the ultimate preventative therapy,” says Alan Flake, a surgeon at the Children’s Hospital of Philadelphia in Pennsylvania. “The idea is to avoid any manifestations of disease.”
The idea may sound alarming, but there is a clear rationale behind it. Use these therapies on an adult, and the body part that you are trying to fix is fully formed. Use them before birth, on the other hand, and you may solve the problem before it even arises. “This will set a new paradigm for treatment of many genetic disorders in future,” says Flake.
Flake has been performing surgery on unborn babies for nearly 30 years, using techniques refined on pregnant animals to ensure they met the challenges of working on tiny bodies and avoided triggering miscarriage. The first operation on a human fetus took place in 1981 to fix a blocked urethra, the tube that carries urine out of the bladder. Since then the field has grown to encompass many types of surgery, such as correction of spinal cord defects to prevent spina bifida.
While fetal surgery may now be mainstream, performing stem cell therapy or gene therapy in the womb would arguably be an order of magnitude more challenging. Yet these techniques seem to represent the future of medicine, offering the chance to vanquish otherwise incurable illnesses by re-engineering the body at the cellular level. Several groups around the world are currently testing them out on animals in the womb.
Of the two, stem cell therapy has the longer history: we have been carrying it out on adults since the 1950s, in the form of bone marrow transplants. Bone marrow contains stem cells that give rise to all the different blood cells, from those that make up the immune system to the oxygen-carrying red blood cells. Bone marrow transplants are mainly carried out to treat cancers of immune cells, such as leukaemia, or the various genetic disorders of red blood cells that give rise to anaemia.
One of Flake’s interests is sickle-cell anaemia, in which red blood cells are distorted into a sickle shape by a mutation in the gene for haemoglobin. People with the condition are usually treated with blood transfusions and drugs to ease the symptoms, but even so they may well die in their 40s or 50s. Some are offered a bone marrow transplant, although perhaps only 1 in 3 can find a donor who is a good match genetically and whose cells are thus unlikely to be rejected by their body. “The biggest issue with treating disease with stem cells is the immune system,” says Flake.
And therein lies the main reason for trying a bone marrow transplant in an unborn baby: its immune system is not fully formed. At around the fourteenth week of pregnancy, the fetus’s immune system learns not to attack its own body by killing off any immune cells that react to the fetus’s own tissues. This raises the prospect of introducing donor stem cells during this learning window and so fooling the immune system into accepting those cells. “You can develop a state of complete tolerance to the donor,” says Flake. “If it works for sickle cell, then there are at least 30 related genetic disorders that could be treated.”
First motion MRI of unborn twins
If you want to get a sense of what it might be like to share a womb with a sibling, this video may give you a glimpse. For the first time, unborn twins have been captured using cinematic MRI, a technique that images slices of the body several times to create a video with astonishing detail.
According to Marisa Taylor-Clarke of Imperial College London, who recorded the images, this is “raw” footage, unlike typical videos of the womb, which require computer processing afterwards. She uses the technique to study twin-to-twin transfusion syndrome, a potentially fatal condition where one twin’s growth is stunted when its sibling receives more of the blood supply.