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Saturday, 30 May 2020

Cryptic Pregnancies (Things We Don’t Know about Pregnancy Series #20)

Some pregnancies are planned, and some pregnancies are unplanned, but few pregnancies go unnoticed. Not so cryptic (or “stealth”) pregnancies, which describe what happens when a woman goes through the bulk (or even all!) of a pregnancy without suspecting.

How does that even happen?

Pregnant woman via Pixabay.
Psychological factors
Cryptic pregnancies have been linked to psychiatric disorders like schizophrenia, depression or personality disorder, but only in a small number of cases, and the evidence isn’t strong enough to prove these have anything to do with it. They have been more strongly linked with past traumas, especially child sexual abuse, sexual assault and domestic violence, and with fear of pregnancy, which appears in the majority of reported cases.

Sociological factors
In many examples of cryptic pregnancy, the women involved did at some point think they might be pregnant, but their circumstances were so unsuitable that they denied the possibility. Correspondingly, cryptic pregnancies often happen to soldiers or women with perilous home lives. This is known as somatic denial.

Biological factors
However, many scientists think that cryptic pregnancy is biological rather than psychological or sociological.

Thursday, 21 May 2020

Categorising Things is “Evil”

We label things every day: that man is tall, this book a thriller, leaves are green. How tall? How thrilling? What shade of green? We take the relative and make it absolute, categorising the life out of it to streamline communication. Labels are the oil on a squeaky gate, and most people never question them.

When I was a child, I hated labels: they didn't make sense to me. Was a tall child tall, or short because they were a child? What if my eye colour wasn't an option on the list? Why did we need to classify books anyway, and where did one genre end and another begin? Wasn't it easier to just describe them? ...Surely that's what blurbs were for.

Categories lead to bad writing. If you learn that everybody can be described as a tall, frizzy-haired bossy woman, you always tell – and never show. Telling is boring. It loses the magic and the mystery of the woman who peers down between dark, raggedy fronds with a floating look and says tartly, "I told you to put the other end on first!"

I resisted for a long time. Declined to answer; drew an extra box on the multiple choice question. But eventually I was indoctrinated. How? Why?

...If you get told something often enough, again and again and again, it starts to sink in. Perhaps you don't understand the categories, but you can pick from them (even if you pick wrong). My teachers needed me to say that my character was bossy so they could prove I understood what adjectives were. Friends had to like the same genre of music. The NHS wanted to classify my growth rate. So I shut up and categorised for an easy life.

Science uses categories all the time. Species separate from species (did you know the only taxonomic difference between moths and butterflies is that butterflies are prettier?). This is incredibly useful for explaining the patterns and rules in science, but it's also limiting. As we discover more science, we have to revise our categories as they no longer make sense: such as the advent of DNA, which gives us new insights into how animals are related, or the discovery that electricity was the flow of negatively charged electrons, which revealed that our "conventional current" arrow went in the wrong direction!

In learning institutions, even the science subjects are carved up and divided: physics, chemistry, biology, maths… Perhaps, then, it should come as little surprise that so many of the unanswered questions in science take place at the intersection of these fields. To answer them, we need people who are experts in different fields talking and working together, but we actually need more than that: we need polymaths, people who are computational biologists, physical chemists, scientific philosophers, and so on…

I had a quick look at the Things We Don’t Know database, and picked out just a few very fascinating things that cross over scientific fields, from biology to physics to chemistry to computer science to geology to engineering to psychology… and so on ad infinitum. These are they:

Could robots soon have 'human-like' vision? 
Research has been carried out into replicating the muscle motion of the human eye using soft materials and pressure-sensitive piezoelectrics. This could allow robots to "perceive" the world in a way we find more intuitive, and may even help us learn about human visual processing.

Could we capture and store our waste carbon dioxide? 
Scientists think that up to 90% of carbon dioxide emissions could, instead of being released, be captured and stored underground or underwater, where, at great depths, high pressure cause it to liquefy. In the ocean, it shows “negative buoyancy”, sinking to the sea floor, whilst in rocks it can be drained into tiny natural pores in rocks: this is called geological sequestration. Scientists are still exploring where this could take place and how long the carbon dioxide could be stored.

Could we treat mental health problems with birdsong? 
Humans may get psychological benefits from listening to bird calls, including boosts to mood, attention and creativity. This “biophilia” – the idea that being amongst nature makes you happier and healthier – is sufficiently established that Alder Hey Children’s Hospital in Liverpool play birdsong in their corridors, as does an airport lounge in Amsterdam! It’s even been applied as a form of dementia treatment. New work led by the National Trust aims to explore how human brains are affected by birdsong.

How can we measure uncertainty? 
Entropy is a measure commonly used thermodynamics to assess the disorder of a system. However, computer scientists and cryptographers now talk about information entropy. The greater the uncertainty about something, the more information is needed to describe it – so the more entropy or disorder. How did photochirogenesis evolve? Photochirogenesis – the development of handedness in biological molecules (where all natural molecules are either left or right hand mirror images of asymmetric molecules), may have developed because of polarised light in meteorites. If this is true, the origin of life could be in stars.

Is time in our minds? 
Is time an illusion? How can we tell? And, if it’s just in our minds, why is it used in classical mechanics equations? Does time really only go in one direction, or is this an illusion of human perspective? Our current direction through time is always forwards by definition, but on what grounds do we define it like this? Underpinning this could help us understand the concept of time travel and the science behind what we really mean by it.

And on that philosophical note… If you or someone you know is working on one of these topics, we’d love to hear from you. Perhaps you can tell us more about how your research is going, or some of the challenges in the field!

I was inspired to write this post after hearing a talk by Dr Julia Shaw on the label “evil”. 'Evil' throws up all kinds of problems not only because it's a highly subjective category (like most), but also because it sticks. Once labelled evil, you are evil forever. You can live a good life, behave well, be compassionate, but screw up once and you are evil. Your misdeed will be carried with you forever and you can never shake off its label. Evil is immortal.

Monday, 11 May 2020

The Causes of SIDS (Things We Don’t Know about Pregnancy Series #19)

What causes SIDS, and why mention it with pregnancy?

Sudden Unexplained Infant Deaths (SUIDs) of infants under a year old occur unpredictably and don’t have an obvious cause. Of around 200 such deaths in the UK every year, around 80% are classified as SIDS – Sudden Infant Death Syndrome (also know as cot death). These are the deaths that can’t later be explained by suffocation, infections, or genetic disorders, even after autopsy.

Baby by Beth [CC BY 2.0], via Flickr

But what does this have to do with pregnancy?

Because SIDS happens to very little babies, many of the risk factors are linked to their mother’s health and what happens before and when they’re born.

Not all of them, of course.

The most commonly cited risk is sleeping position: babies on their backs are less likely to suffer stress complications, like restricted breathing or bedding entanglement, than babies placed on their fronts, sides, or co-sleeping.

There could also be a seasonal component, since more SIDS deaths occur in winter. However, this could instead be because parents use more bedding or babies are more likely to get sick.

And there are genetic factors. For example, boys are more likely to suffer from SIDS; one study cited a 50% male excess in SIDS per 1000 live births of each sex[1]. There may be a racial component too (although it’s not clear from the literature whether this has been disentangled from socioeconomic components). Or inherited defects could play a part, such as in channelopathies, ion channels related to the contraction of the heart, which may explain 10-20% of SIDS[2].

During pregnancy, maternal health is a key indicator for SIDS risk. Mums younger than 20, who smoke or take drugs, or get poor prenatal care are more likely to have babies that suffer from SIDS[3]. They’re also more likely to have babies born prematurely (increasing their risk x 4) or underweight (increasing their risk by x 5.7 for 1000–1499 g babies versus 3500–3999 g babies)[4]. An elevated risk is even seen in full term babies born before 39 weeks.

Tuesday, 28 April 2020

Depression During and After Pregnancy (Things We Don’t Know about Pregnancy Series #18)

Postnatal depression is thought to occur in ~1 in 10 mothers, making it a common form of mental illness. The onset and peak of the illness may be weeks or even months after the birth of a baby, and the condition lasts for weeks, months, or longer.


The condition is characterised by persistent negative feelings – towards yourself, your baby, and things you previously had an interest in. Most parents find their inability to bond to their baby most upsetting, and many feel guilty, hopeless, and even suicidal. Physical symptoms include disturbed sleep, tiredness, increased or decreased appetite, and difficulty decision-making.

We don’t know what causes postnatal depression

We don’t know what causes postnatal depression, although it’s associated with hormonal changes, such as a drop in one hormone called allopregnanolone. But these alone can’t explain everything. Women go through huge and varied hormonal changes during pregnancy and early motherhood, and postnatal depression doesn’t effect everyone. In fact, for a long time, people believed that pregnancy hormones were protective against depression, and it was simply something new mothers couldn’t get – leading to many undiagnosed sufferers[1].

Worried Woman Image credit: RyanMcGuire (CC0 Public Domain via Pixabay)

Monday, 20 April 2020

New site feature - follow the story

We are very happy to announce a new feature that has been rolled out across the Things We Don't Know website - automated links to other science websites to help you follow the story behind the research that interests you most.

Our objective here at TWDK is to help people follow the story behind ongoing research into specific scientific topics. We describe the background, and then help you to find news and updates about that research from other sources. Until now, these updates have relied on scientists using our site posting an update manually, or our staff doing so. But now we have started to automatically check a number of sites to see if they've posted anything that is related to our articles. For example, you will now find at the bottom of our article about unanswered questions in artificial intelligence something like this:

Snapshot of "recent science news" related to artificial intelligence from the TWDK website
Snapshot of "recent news" items at the bottom of our article on unanswered questions in artificial intelligence

If you happen to have subscribed to the article, then these links will also appear in your customised feed on the TWDK homepage.

We will gradually increase the number of sites we check for science news that matches our articles, but to begin with we're automatically creating links to articles from the following sites:

We don't import or copy any material from any of these sites - we just add a link from our article to theirs.

These seventeen sites were selected to present a broad range of scientific updates from reputable sources. If you've got a site and you'd like us to add it to our list, just let us know in a comment below.


This guest article was written by Maxwell Holle from the University of Illinois.

A simple glass of milk holds the potential to become hundreds of different types of cheeses with a variety of different flavours. But with so many diverse flavours and styles, how can we identify an off-flavour?

Image by corinnabarbara from Pixabay.


What is cheese?

Cheese is milk that we force into a gel by either acid, heat, or enzymes. While making cheese, we try to remove as much water as possible, which also means losing some milk proteins. The simplest cheeses stop here and are known as fresh cheeses; they have a relatively salty and neutral taste. However, most cheeses take on their characteristic flavours and smells during the ageing and ripening stage, where diverse groups of microorganisms get involved. These microorganisms generate the characteristic flavours of some of our favourite cheeses.

Wednesday, 15 April 2020

Birth trauma (Things We Don’t Know about Pregnancy Series #17)

PTSD (post-traumatic stress disorder) is still a condition associated with soldiers. Men. But every year, estimates suggest 4% of births cause maternal PTSD [1]. We call this birth trauma.

Birth trauma was first recognised in the 1990s, when the American Psychiatry Association modified its definition of a traumatic event. It’s now thought that it may affect fathers who were present at the birth as well as mothers.

I recently visited the Oxford Spires – a midwife-led unit where mothers with no complications can give birth in a relaxed environment. It sits conveniently a few floors above the main hospital, so emergency treatment is only a lift journey away. But amongst the pools and mood lighting, the giant squashy birth aid balls and the ergonomic beds, I was struck by how much could go wrong during birth.

And I don’t just mean physically.

Obstetric forceps. Killian 1842 via Wikipedia Commons.

Thursday, 2 April 2020

How much do unborn babies sleep? (Things We Don’t Know about Pregnancy Series #16)

We can’t measure the brain activity of a human foetus – not whilst they’re inside their mother. But we’re really interested. What happens to a baby’s brain as it’s developing, and what does this tell us about our own and the developing process of sleep?

EEG (electroencephalogram) reading via Wikipedia Commons.
Researchers into brain activity have performed EEG (electroencephogram) exams on premature babies, and monitored eye movement in the womb to learn about sleep cycles, although big errors with these kinds of measurements are common. They have, however, detected REM (rapid eye movement) sleep from around 7 months, when the brain cycles in and out of restful and REM (rapid eye movement) sleep every 20 to 40 minutes. From 7 months onwards, foetuses mostly sleep (90-95% of the time at 32 weeks, 85-90% by 37 weeks). After it develops, REM sleep increases and increases, reaching a lifetime high of 12 hours a day just before the baby is born.

Very little is known about foetus sleep before this. For example, we don’t know if sleep and sleep cycles suddenly or more gradually develop with the foetal brain. New research into lambs has shown that foetuses enter a dreaming-like brain state weeks before REM sleep starts[1]. As well as learning more about sleep, this study could help us figure out how the brain develops and when it is most at risk.

Equally, neurons in the brain develop much earlier, with those responsible for sleep present long before REM sleep is seen.