Professor Marian Knight

Brief Outline: Professor Marian Knight, National Institute for Health Research (NIHR) Research Professor in Public Health, National Perinatal Epidemiology Unit, Oxford University. Chief Investigator for the National Maternal Near-miss Surveillance Programme (UKNeS)www.npeu.ox.ac.uk/uknes.

Background:

A greater understanding of women's experiences of these life threatening complications can...

 

As I said they don’t happen very often, but when they do happen, they’re very severe and they mean that we need to take urgent action very quickly. So it’s important that we study these complications, so that we as nurses, doctors and midwives, know how to treat women very quickly, to help safe their lives.

 

But also they can have long term complications, so they can impact on women, and their families and their partners for a very long time into the future. And again it’s important that we study women and their experiences so that we can put in place services to help women to come to the terms with the consequences over a long time.

 

Professor Marian Knight explains the four broad groups of conditions that can lead to life...

 

So firstly we think about conditions relating to high blood pressure in pregnancy. So high blood pressure can lead to a condition called pre-eclampsia, where a woman gets proteinuria, protein in her urine. She can also develop even more severe complications as this, fits in pregnancy which is a condition called eclampsia. There are two other related conditions, so HELLP syndrome where there are problems associated with high blood pressure and problems with blood clotting. And also you can get the woman’s liver affected, in a condition called acute fatty liver of pregnancy.

 

There’s also conditions relating to haemorrhage. So if a woman bleeds more than is normal she made need blood transfusion, but she may need a hysterectomy to help, in fact save her life, to stop the bleeding. This can be associated with disorders of the placenta, so bleeding is more likely if the placenta is attached to the womb in the wrong place. So if it covers the birth canal this is a condition we called placenta praevia or if the placenta invades too far into the wall of the womb, which is a condition we call placenta accreta. Similarly if the placenta detaches too early from the womb it may cause something called placental abruption. All of these placental disorders can cause problems with haemorrhage.

 

Additionally, woman can develop blood clots. So blood clots in the legs which are known as deep venous thrombosis which can break off and then travel to the lungs which is called a pulmonary embolism which can affect a women’s breathing quite significantly.

 

And one other main category is related to infection. So women are more susceptible to infection in pregnancy. So when its become severe we call it sepsis or indeed septicaemia when its spread into the blood stream.

 

What is a haemorrhage after childbirth, and why is bleeding beyond the normal dangerous for a new...

 

Most women have a small amount of bleeding after they’ve given birth and this is entirely normal. However this can become very much worse due to various conditions. So it can be that the womb failed to contract down properly after the woman has given birth. It could be that there’s a piece of placenta that’s been left behind which can mean that the haemorrhage becomes very much greater. There can be issues with where the placenta is actually implanted in the womb, which can also make a woman much more susceptible to haemorrhage.

 

We usually classify a haemorrhage, a post partum haemorrhage as more than expected. If its more than about a pint of blood. Women can lose, can lose several pints of blood and obviously that means that they have to have emergency treatment, such as blood transfusion, obviously to save their lives.

 

And why would a haemorrhage be dangerous to a woman?

 

Clearly any bleeding beyond the normal is going to be a problem for any of us. And especially we an lose a large amount of blood very quickly after child birth, because there’s a lot of big blood vessels which have been feeding the placenta and obviously keeping the baby alive. And if you lose more than a significant proportion of your blood stream, obviously you can’t get oxygen to, to feed all your organs and clearly that’s going to be a major problem for you. It clearly needs urgent action to stop the bleeding.

 

 

Professor Marian Knight describes placenta accreta and other problems that can develop with the...

 

So the placenta normally attaches to the inside of the womb and its normally attached relatively close to the surface, so that actually when the baby’s born the placenta can detach relatively easily. There’s a range of conditions where the placenta is actually embedded rather too deep into the wall of the womb and in some cases can be, invade all the way through the womb and in fact, start to damage other organs such as the bladder which is lying close by. That obviously means that the placenta is very difficult for it to come away after childbirth and this can lead to major bleeding.

 

Another condition which is related to this, which is called placenta praevia, is where the placenta actually implants too low down in the womb and actually covers the birth passage, so that the baby can’t be born normally. And women with these conditions are most likely to need delivery by Caesarean Section. And again they can be associated with significant bleeding or haemorrhage.

 

And why does retained placenta cause bleeding?

 

After a woman has given birth and the placenta has been delivered normally, the womb contracts down really tight and this helps to block off any bleeding from the big blood vessels which have previously been feeding the placenta. If the placenta is still in the womb, clearly the womb can’t contract down in that same way, and the, these large blood vessels will continue to bleed, and that’s one reason why, if the placenta is retained, the woman is likely to carry on bleeding quite significantly.

 

Professor Marian Knight describes pre-eclampsia and HELLP syndrome.

 

Pre-eclampsia is the condition related to high blood pressure in pregnancy, in which women also get complications such as protein in their urine, and it can if it gets very severe, lead to symptoms such as headaches and flashing lights and a woman can get a type of fits in pregnancy, which is known as eclampsia.

 

There are other complications which are related to pre-eclampsia which also fall into the sort of category of really severe complications in pregnancy. One of those is HELP syndrome which affects the blood clotting and another is acute fatty liver, which affects the way the liver works in pregnancy.

 

And why are these conditions dangerous?

 

Unfortunately if they are left untreated a woman can die. If you’ve having severe fits it obviously means that your brain is affected and therefore its really important that women get treated very early to bring their blood pressure down, and in fact the ultimate cure we have is to deliver the babies. So women who have very severe complications of pre-eclampsia well may need to have their baby born early.

 

What are thromboembolic (blood clotting) conditions during pregnancy, and why they are dangerous...

 

So for some women in pregnancy the blood becomes slightly thicker than it would normally, and this can mean that you’re more susceptible to the blood clotting in the vessels where it wouldn’t normally… so the most common complication is a blood clot in the leg veins, which is called a deep venous thrombosis. Which itself is an important complication that needs to be treated with blood thinning agents, but can become even more severe, if part of that blood clot breaks off, because it then lodges in the lungs and that can mean that a woman has quite severe breathing problems and it can mean that she doesn’t get enough oxygen into her blood, which obviously affects the oxygen.

 

Can you explain to me the difference between a deep vein thrombosis and a pulmonary embolism?

 

So the difference is that the deep vein thrombosis normally forms in the legs and that’s where the blood clot actually forms. Clearly that affects the circulation to the legs, but doesn’t have a wider impact on circulation elsewhere. If a piece of that blood clot breaks off, because of the route that our blood takes, those blood clots will end up in the lungs. And that can block off all the blood vessels supplying quite substantial parts of the lungs and this can particularly affect our ability to absorb oxygen from when we breathe. So clearly affects if we’ve got a low oxygen level in our blood that can affect the working of all of our organs and can indeed compromise the oxygen supply to the placenta.

 

And why are these events, these clots more likely when a woman is pregnant or shortly afterwards?

 

Our blood changes quite a lot when we’re pregnant, so the different composition of the blood when we’re pregnant does mean that it is in effect slightly more likely to clot. And it does mean that if we are for example, immobile for a significant amount of time, it might mean that if your immobile and pregnant you’re much more likely to blood clot, to have a blood clot. In addition obviously you’ve got a large womb which can press on the blood vessels, which again can make them more likely, you more likely to have a blood clot. There are some women who have an inherited tendency to be more likely to have a blood clot, and this can only become obvious in pregnancy, when they’ve got an additional reason why they might be, get a blood clot. Which is why you’ll find if you’re a woman who has a blood clot in pregnancy you will probably undergo a number of tests to see if you’ve got one of these inherited susceptibilities.

 

What is a life threatening complication in pregnancy and childbirth?

For most women, childbirth and pregnancy is complication free and a very happy event for all. But for a very small number of women there can be major complications which mean that we as doctors, nurses, and midwives, need to act very rapidly to, to help save the women’s life, or indeed save the baby’s life. They don’t happen very often, but they do happen and so we do have to be aware of how to manage these conditions.

 

I’m talking about conditions such as pre-eclampsia which is severe high blood pressure in pregnancy which can lead o a condition called eclampsia, which is a sort of epileptic type fits in pregnancy. Severe haemorrhage where the woman has a lot of bleeding, which is obviously a very severe complication.

 

Other examples, such as blood clots, which can form and particularly when the blood clots reach the lungs, can have major implications for a woman in her pregnancy.

These complications are rare. Overall, they affect less than one in one hundred women. So for...

 

So we estimate that when we’re thinking about these severe complications as a whole, probably one in every one hundred women will be affected. But each individual condition probably affects far fewer women then that. So for example, if you have a severe haemorrhage you may need to have a hysterectomy actually to save your life. But we estimate that that happens only once in, for one in every 2,000 women.

 

Some complications such as amniotic fluid embolism are very, very much rarer, so we estimate that probably only one in every 10,000 would be affected by that.

 

What is sepsis in pregnancy and why it is dangerous in women who have recently given birth?

 

In pregnancy we can be susceptible to a lot of things which normally, when we’re not pregnant wouldn’t make us severely ill and sepsis is one of these. Sepsis is just the generic term for severe infection. But in pregnancy because of alterations to our immune system it does mean that we’re more susceptible to severe infections. This is particularly the case immediately after we’ve given birth. When obviously it’s quite traumatic. There are open wounds, whether you’ve had a normal birth or a Caesarean delivery and it can mean that you’re much more likely to get infection and if the infection is severe it can lead to sepsis or indeed septicaemia where the germs get into the blood stream and can make women very ill.

 

 

What is amniotic fluid embolism and why it is dangerous to the mother?

 

Amniotic fluid embolism is a very rare complication of pregnancy. It’s usually associated with some of the amniotic fluid which is the water which surrounds the baby in the womb, getting into the Mother’s circulation and we think, causing an allergic type reaction, which can mean that it might be as severe as, as causing the woman’s heart to stop, but certainly can mean that she gets very low blood pressure and problems in getting oxygen to the rest of her circulation.

 

In particular, it often causes problems with blood clotting, so it can mean that the woman becomes very prone to bleeding, and obviously if you’ve just given birth you’re more likely to, you’ve got bleeding anyway and it can make the bleeding, after child birth extremely severe and we need to intervene, with rapid treatment, with transfusion of blood and other of the products to help the blood clotting.

 

Professor Marian Knight outlines the main complications of these life threatening conditions for...

 

I think you can probably think about the complications in, in two groups. There are complications that happen at the time of the event, so women may often end up needing nursing in Intensive Care after they’ve had one of these complications. Obviously we’ve mentioned that some women may end up having a hysterectomy, which obviously has a longer term recovery process. But it’s also clear, as you’ll hear from some of the experiences of some of the women talking, within this website that actually there can be much longer term consequences.

 

So the second group is thinking about issues such as, post traumatic stress disorder, for example, the feeling that women, will need debriefing for some years afterwards because of aspects of the event that come back to them. There may well be longer term physical consequences as well. I mentioned hysterectomy, blood clots in the legs, can mean that you have longer term problems with your, with your legs.

 

So there can be impacts that are both short and long. I guess the important thing is that every woman is different and not all women will have long term complications and they may find for them they’re a very short term event. But we hope that sharing some of the experiences of the women on this research you’ll be able to find somebody who has a similar experience to you.