Hello and welcome to this lesson from the Unit: Reproduction in Humans.

The title of today's lesson is Healthy Pregnancy.

We're going to be looking at how a mother's lifestyle choices can affect a growing foetus, such as smoking, drugs and alcohol, and what the long-term and short-term effects on the foetus may be.

My name's Mrs. Barnard, and I'm going to be taking you through today's lesson.

So by the end of today's lesson, you should be able to name some of the substances that can pass through the placenta and explain the effects that they have on a developing foetus.

So we've got some key terms in today's lesson, and our key terms today are drugs, foetus, alcohol, and placenta.

Now, I won't go through them individually, but if you do want to write them down, I'll put the definitions up and then you can pause the video and then come back to restart the lesson.

Okay, so our lesson today is in two parts.

The first part is harmful substances, and we're going to be talking about the kind of substances that can affect a developing foetus.

And then we're going to be looking at the long-term and short-term effects that they have specifically on the foetus for those particular substances.

So let's get started with our first part of the lesson, which is harmful substances.

So drugs.

Now, drugs is a word that you might hear in everyday life, but it's really useful for us to have a clear definition of what it is.

So drugs are substances that, when you take them in, will have some kind of effect on the body.

Once they're in the body, they travel around in your blood, 'cause the blood is the transport system for everything that goes into your body.

And eventually that blood will make it to the brain, because most drugs have more of an effect on the brain than they may have in other places in the body.

Some drugs might be taken as medicines.

Now, medicines may be ones that you get on prescription.

So that means when you go to the doctor and they give you a little slip of paper and you take it to the chemist or the pharmacy, and they will provide the medicines that you need to relieve symptoms or treat a particular illness.

Other drugs, people take by choice, and they are taken recreationally.

So some people take drugs because they enjoy the feeling that it has.

So not because they have an illness or because they're relieving the symptoms of pain, 'cause they like the effect it has on the body.

Now, that is called the recreational use of drugs.

And recreational drugs might be legal or illegal.

So illegal means that it's against the law to take them, and there's certain punishments that are associated with the type of drug, which is usually to do with how dangerous that drug is.

So you can have a quick discussion with the person next to you.

Can you name any drugs that you think are illegal or drugs that you think that are legal, which means that you are allowed to take.

Okay, I hope you got to share your ideas.

We're we are specifically going to be focusing on legal drugs.

So the examples of legal drugs that you are allowed to take are alcohol and nicotine in cigarettes.

So the cigarettes themselves aren't a drug, but the nicotine in the cigarettes is a drug.

Now, in both cases these do still have laws associated with them, because you're not allowed to buy either of them until you are 18.

So therefore the government has decided that they are harmful to a certain extent, which is why they've put these limits on the age for buying them.

So, time for a quick check.

So choose which of the substances below are drugs.

So pause the video while you decide, and then we'll come back and we'll see how you got on.

Okay, let's have a look at them.

So remember, drugs, when they're taken into the body, will have an effect.

Okay, so drugs here are alcohol, okay, which is a recreational legal drug.

Then we have prescription medicine.

So those are medicines that we take to relieve pain or to treat an illness.

And nicotine.

Nicotine is the drug that's in cigarettes.

It's the drug that makes cigarettes really addictive.

Okay? It has other negative effects on the body, but that's one of the main things that makes it difficult.

Okay, so drugs can have harmful side effects.

Now, really all drugs have side effects.

Now, you might know that when you get medicines, even prescription medicines, they come with leaflets, and those leaflets will list all of the different side effects that you could possibly get.

Sometimes it tells you like what percentage chance you've got of getting all of those different side effects.

But the point of prescription drugs is that it's a balancing act, and you are taking those drugs because of the positive effect that you need.

The need for them outweighs the possible side effects.

However, if a pregnant mother takes drugs, the drugs can pass from her blood into the foetuses.

So it can affect the growing foetus.

That is why during pregnancy, even lots of prescription drugs, they ask that pregnant women don't take or over-the-counter medicines you are asked not to take, because they can have an effect on the foetus.

So illegal drugs.

Okay.

So you might have discussed some of those.

Examples are cocaine, heroin, those things, cannabis.

Once they're taken into the body, they move into the blood.

Some of those are injected directly into the blood, So that's how they get into the bloodstream.

Other ones are breathed in, so like cigarette smoke or smoking cannabis.

Those drugs will be taken in through the lungs and then in the lungs they then pass through the very thin lining of the alveoli into the capillaries in the lungs, and that's how those substances get into the blood.

And then, finally, you might consume some drugs, so, for example, alcohol.

So when you drink alcohol, it goes down into your stomach and then into your small intestine.

And that alcohol will be absorbed from your small intestine into your blood.

So all these drugs and chemicals eventually end up in the bloodstream.

And in this case, we're focusing on the bloodstream of the pregnant mother.

And then from here, they're transported around the body and they will go to the placenta.

And you may remember from the previous lesson, the placenta is the organ that is shared between the mother and the foetus, and it's where substances are exchanged.

So we say that recreational use of drugs is a lifestyle choice.

So therefore, these are not drugs that are needed to treat a disease or an illness.

These are drugs that are being chosen to be taken for the effects that they have.

That is recreational use.

And that is the choice of the mother.

It's a lifestyle choice.

And substances that are harmful to adults, even mildly harmful to adults, will have more of an effect on the foetus, because the foetus is really small and it's still developing.

So any substances that are travelling around the blood of the mother that end up in the blood of the foetus is going to have more of an effect on the foetus, and they will pass to the foetus via the placenta.

The placenta is a really important organ that we've covered in previous lessons, and that's because it allows the exchange of substances from the mother to the foetus.

So we need the blood of the mother and the foetus to flow next to each other, because that allows oxygen and nutrients to pass from the mother to the foetus.

It also allows the waste products of the foetus, like carbon dioxide, which is a waste product of respiration, to be passed to the mother's blood so the mother can excrete them.

And we can see here the blood vessels, just a little recap here of how close the mother and the foetus' blood vessels are to each other.

So as the oxygen and the nutrients pass from the mother's blood into the foetus' blood, they will travel down the umbilical cord to the foetus.

But so then can other substances, chemical substances, such as drugs, nicotine from cigarette smoke, and also alcohol.

So they'll pass across in the placenta to the foetus' blood and down the umbilical cord.

And then that's how it will affect the developing foetus.

So, time for a quick check.

Alcohol is harmful to a foetus but not to adults.

Now, do you think this statement is true or false? And once you've decided, which of the statements below do you think best justifies your answer? So pause the video while we do this, and then come back and we'll see how you've got on.

Okay then.

So alcohol is harmful to a foetus but not to adults.

This is false.

And the reason is because alcohol is more harmful to a foetus, as it's smaller and still developing.

But an alcohol is still harmful to adults.

Okay? In low dose is not as noticeable, obviously, 'cause we know that alcohol is quite normal in everyday society, but every drug, as we've said, does have side effects.

So, another check then.

Which of the following substances can pass from a mother to the foetus through the placenta? Again, pause up while you make your decision.

Okay, so with this check, the substances that can pass through are alcohol, oxygen, and nicotine.

Not red blood cells because the blood of the mother and the foetus do not mix.

The blood vessels just run close to each other, so red blood cells don't pass across.

Okay, time for a practise task.

So Izzy has started to do a basic drawing of a placenta.

So what I would like you to do is I'd like you to copy this basic diagram down and label the mother and the foetus' blood vessels.

And then the second part of this task is to label the substances that can pass from the mother's blood vessels to the foetus' blood vessels.

And if you labelled it with arrows to show the direction that those substances pass.

Okay, so pause up while you do that, nice, big, neat drawing so that you can see them easily, labelled neatly, and come back and we'll see how you've got on.

Okay, let's see how you got on then.

So we should have copied this diagram as well as we could, and then labelled it placenta and with the arrow road to the foetus.

And then the foetal blood vessels of these ones here that are attached on that are going down the umbilical cord to the foetus.

And then the mother's blood vessels are those ones that are on the other side of the placenta.

'Cause that's going to be attached to the wall of the uterus where the mother's blood vessels come in.

And then the substances that can pass across.

Okay, we've got alcohol that can move across.

We've got nicotine, we've got drugs.

You might have also have put oxygen and nutrients on there, if you want to, just to show there are some things moving across that should be moving across at the same time.

But if you've got those right, then well done.

And it's time to move on to the second part of our lesson today.

And the second part of our lesson is the effects of these substances on the foetus.

So taking drugs, smoking, and drinking alcohol during pregnancy are lifestyle choices.

They are choices by the mother.

And all of these choices increase the risk of miscarriage.

So what miscarriage is, it is the sudden loss of a pregnancy before the 20th week.

So remember pregnancy gestation period is 40 weeks.

So if the baby is suddenly lost before 20 weeks, this is called a miscarriage.

Now, this can happen very early on in the pregnancy at just a few weeks, or it can happen all the way up to 20 weeks.

So here's an image here of a foetus at 16 weeks, just to show that it does sort of look like a human baby at this point with arms and legs.

So it can be really devastating news for the parents of that baby.

Now, miscarriages do happen all of the time.

They are quite common.

But these substances, these lifestyle choices do increase the impact of this, the likelihood of this happening.

And when miscarriage happens, the baby dies, the foetus dies.

So drugs and smoking, the reason that they have an effect on the growing foetus is because they can slow down the growth of the foetus, because they reduce the oxygen supply.

So not enough of the blood that contains a rich oxygen supply is getting to the foetus to allow the foetus to carry out respiration, and that respiration is a process that helps with growth.

And what this means is that this can lead to a premature birth or a baby with a low birth weight.

So a premature birth is when a baby is born early, so before full term.

So 40 weeks is full term.

They usually give sort of two weeks either side of this, which would be like a normal range for a baby to be born.

But anything before this would be premature.

And when a baby is premature, there's more of a risk during childbirth 'cause that baby is much smaller, so the delivery process is more difficult.

It puts more stresses on their body and their organs.

But also, even babies that go to full term, if their mother has taken drugs or smoked or drank a lot of alcohol, then that baby may still be born with a low birth weight and organs that may not have developed properly, and that might lead to complications later in life.

So even though that baby has been born and can go home, okay, and be looked after like a normal baby, it could have complications that follow it through.

Here's a picture here of a premature baby that was born about 30 weeks.

You can see that nappy on that baby is a newborn nappy, so it's still tiny compared to that.

This baby is about 30 centimetres long, so about the length of a ruler that you would have in the classroom, from top of the head to the bottom of the feet.

Sometimes it's difficult to see size in a picture.

So alcohol and drugs can have effects on the baby and continue after they're born.

So those first effects that we were talking about, the low birth weight and the premature birth, are effects that happen in the short term.

But some of these others are effects that happen in the long term.

So, for example, alcohol can cause a condition called FASD, so foetal alcohol spectrum disorder.

And this is when drinking too much alcohol can affect the growth of a foetus and the development of its organs, and can have effects on and later into life.

Smoking during pregnancy can increase the chances of sudden infant death syndrome or SIDS.

Now, sudden infant death syndrome is an awful thing to happen, and it can happen even if a mother doesn't smoke.

But smoking during pregnancy has been shown in research to increase the chances of this happening.

And this is when a baby dies seemingly for no reason below the age of one, then it would be called sudden infant death syndrome.

And finally, taking drugs during pregnancy can lead to the baby actually being born addicted to that drug.

And when that happens, that baby has to be taken away from its mother and treated very, very quickly for withdrawal of those drugs.

So you can see there's a picture here of a baby in an incubator.

So with foetal alcohol spectrum disorder, because it affects the foetus growing, it will affect the development of some of the organs.

So here are some of the features that you might see in a child with this disorder.

They would have problems with learning, with some organ and muscle function, and also with managing some of their emotions.

And this is because the brain hasn't developed fully.

So, for example, there are fewer brain folds and that means the brain is a bit smaller, and some of the things that you need those folds for in order to operate an easier life, they're not there.

And they have a smaller cerebellum.

Now, so cerebellum is the part of the brain that controls coordination and muscle function.

And then you can see that they might have some difficulties with their ears, 'cause those organs haven't developed properly.

They'll have a smaller head due to the smaller brain, because of the reduction in the different areas of the brain.

And they may have a shorter and a flatter nose.

Now, it takes quite a high alcohol intake in the mother for this syndrome to be caused in a foetus.

But the higher the alcohol intake, the more the increased risk there is of this disorder in their child.

And that is a long-term consequence.

So, let's have a quick check.

Which of the listed effects below are the short-term consequences of a pregnant mother's lifestyle choices? So if you want to pause the video while you decide, and then we'll see how you've got on.

Okay, so the short term consequences are that the baby might be born early, so a premature birth.

A miscarriage might occur, so that the foetus dies before 20 weeks.

Or the baby might be born with a low birth weight.

So if you've got those right, then well done.

So another task for you now.

So this is a practise task.

I would like you to match up the key word with the feature that would be a long-term effect, a possible long-term effect.

Because with these substances, you're only increasing the likelihood.

It's not a definite.

So what is a possible long-term effect? Okay, let's see how we got on with that one then.

So alcohol, it can cause foetal alcohol spectrum disorder, so FASD.

Smoking can cause SIDS, sudden infant death syndrome.

And drugs can lead to addiction.

So if you've got those right, then well done.

So it's time to move on to another practise test.

Now, this is quite a creative test, so I hope you're able to get some poster paper and some felt tips, or you might want to do it using a computer.

But Aisha, Sam, and Andeep are designing a poster to educate pregnant women on healthy lifestyle choices.

They are deciding what features it must have.

And Aisha says, "I think it should have a picture to show the placenta." And Andeep says, "I think it should include information on which substances are harmful." And Sam says, "I think it should include the effects of substances on the foetus." Now, all of these pupils have really good ideas, but what I would like you to do is, first of all, discuss what other features could be included on the poster, so things that you've learned in today's lesson and possibly in previous lessons too, and design a poster that educates women on healthy lifestyle choices.

So you'll probably need quite a bit of time to do this, but we can come back and we can have a look at what you've included afterwards.

So if you pause the video and then go and have some fun.

Okay, let's see how you got on then.

So the pupils all had some good ideas.

So the first thing was to discuss some other features that you could include, and then for you to go away and design that poster.

So the other features that you could have included would be a diagram of the placenta, which would be labelled to show how the substances cross from the mother's blood to the foetus' blood.

Information on the short-term effects of smoking, alcohol, and drugs, so miscarriage, premature birth, or low birth weight.

And information on the long-term effects, so drug addiction, SIDS, sudden infant death syndrome, and FASD, foetal alcohol spectrum disorder.

So if you included all of those, that's great, and anything extra I'm sure would be brilliant.

So well done for your work in today's lesson.

Here is our summary.

So some substances can pass through the placenta, including some drugs, alcohol, and chemicals in cigarette smoke, for example, nicotine.

These are all forms of drug which have a greater effect on the foetus than the mother and are lifestyle choices.

The substances pass from the mother's blood to the foetus' in the same way as oxygen and nutrients, as the blood vessels are close to each other.

These substances can affect the growth of the foetus and lead to miscarriage, premature birth, and low birth weights in the short term.

In the long term, the consequences for the baby may be drug addiction, sudden infant death, or foetal alcohol spectrum disorder.

So, well done for your work in today's lesson.