Does Stress Cause Miscarriages

Posted on 17 December 2018

Interviewer: Welcome to “Knocked up”, the podcast about everything to do with getting pregnant with Dr. Raelia Lew from Women’s Health Melbourne. Miscarriages have been mentioned in the Australian media this week. And today with Dr. Raelia Lew, we’re going to talk about what they are. how they happen, how can I be caused by stress? And how miscarriages are no one’s fault.

Dr. Raelia Lew thank you. Tell us about what a miscarriage is.

Dr. Raelia Lew: Miscarriage is when a pregnancy goes wrong at an early stage. It can involve losing a baby in the first trimester, that’s the most common kind of miscarriage. Tragically some women do lose the baby at the second trimester before 20 weeks and at that point it is still defined as a miscarriage as opposed to a stillbirth. If you lose a baby after 20 weeks, it’s recognized as a still birth.

Interviewer: Rather than a miscarriage?

Dr. Raelia Lew: Rather than a miscarriage. That’s because we have to draw a line in the sand, I guess somewhere for the definition. In terms of the patients experience, a woman’s experience, whether you lose a baby at 19 weeks or 20 weeks, it would still involve the same amount of heartache.

Interviewer: The same heartbreak. Absolutely.

Dr. Raelia Lew: So, a miscarriage is nobody’s fault and as far as the medical fraternity field (based on the current body of evidence) it can’t be caused by emotional stress alone. Not to say that emotional stress can’t have severe and serious impacts on health, definitely it can.

Interviewer: And certainly stress can impact conception.

Dr. Raelia Lew: Yes, absolutely. So some women when they stressed, be it physical stress, like excessive exercise or dietary stresses like Anorexia nervosa, being stressed in terms of the burden of disease on your body for any chronic illness. Sometimes women stop ovulating because of those kinds of stressors and so they can’t get pregnant. But once you’re already pregnant, we don’t think that the way you feel or emotional stresses in themselves, can impact an early pregnancy. That’s because of pregnancy is relatively protected from our emotions and the way I explain it to patients is the pregnancy is kind of on autopilot while developing in those early weeks. The behaviors that we have and the things that we do most of the time can’t impact that.

There are some behaviors that can increase a woman’s risk of miscarrying. Things like smoking cigarettes, abusing substances, having physical impacts to the pelvis, like an injury, car accident or assault. But emotional stress alone we think cannot cause a miscarriage.

Interviewer: Okay. So, this is a sort of a topic that so far has it has been researched and so far there is nothing conclusive showing that stress alone would cause miscarriage?

Dr. Raelia Lew: Yeah, but having said that, the research that’s been done, it’s very difficult to do robust research in this area and that’s because stress is something that’s quite subjective.

Interviewer: It’s completely subjective, yes.

Dr. Raelia Lew: But in terms of research that’s looked at measuring women’s stress hormones in the cohort of women and seeing if women with a higher cortisol level, (which is the marker of a stress hormone) are more likely to miscarry. That hasn’t shown any evidence that that’s the fact. There have been studies that have looked at stress and miscarriage over the years and some have hinted that there may be an effect, but, when you look at the full body of evidence it’s just not there in terms of proving any causative link between stress and miscarriage.

Interviewer: So if stress doesn’t cause miscarriage, what does?

Dr. Raelia Lew: A miscarriage is caused by a mistake made by baby and another cause can be dysfunction or disruption of the environment of a pregnancy. Most mistakes made by babies are genetic and I’ll talk a little bit about that in a minute. Other mistakes made by babies are spontaneous errors in development. One thing that I talked to my patients about is that every pregnancy is a miracle and to make a normal baby from to single cells merging together, to go in and make an amazingly complex human being involves multiple series of events without a single error occurring.

Interviewer: Which is why we call it the miracle of life.

Dr. Raelia Lew: It is a miracle. And if there’s an event along the line where things don’t go to plan, that can cause a miscarriage.

Interviewer: And so, there are millions of opportunities for something to not go right?

Dr. Raelia Lew: Literally millions of opportunities. So, it’s amazing that we don’t see more miscarriages, but we do see a lot. I mean miscarriage is very common.

Interviewer: Right, so very common. What does that mean?

Dr. Raelia Lew: What it means is that most women who have a normal baby will also have had a miscarriage. One in five pregnancies miscarry overall, but based on the fact that miscarriage becomes more common as women get older, if you’re 40, for example, one in two pregnancies conceived will end in miscarriage.

Interviewer: So we’re saying that now, based on the population mix and when women are having babies, it’s about one in five. But as we’re getting older, that number is going to become one in four, one in three and then as you get older it’s the statistic adapts to you. So, whilst it might be one in five for the overall population of women in Australia trying to get pregnant, it’s one in two for forty-year-old woman.

Dr. Raelia Lew: Yeah, that’s right. And in terms of women who are over 43, it’s the vast majority of pregnancies that are going to end in miscarriage. So, you can say that it is a really common. One thing is we don’t talk about it.

Interviewer: We don’t, we don’t talk about it and it’s such a sensitive topic that you can’t talk about it with your friends. Or when you do as I try to, sometimes it doesn’t end well. So why is it such a common thing, why aren’t we talking about it?

Dr. Raelia Lew: I think it’s cultural and I think it’s historical and I think we should really be trying to change that. I mean it’s quite common in my practice for most women not to tell anyone they’re pregnant apart from their partner until they reached the end of the first trimester. And certainly, that was true also socially for me, among my friends and when I had my own children, I probably did the same thing.

Interviewer: I think it’s just starting to change. I know with my, within my social group to very recent pregnancies, I’ve had friends tell me that will pregnant, well in advance of the end of their first trimester. They said it’s because if they did miscarry, the people that want to talk about the miscarriage with will be the same people they’d want to celebrate the pregnancy with. And that’s why they wanted to talk about it early on.

Dr. Raelia Lew: Yeah. I think there’s also a perception that they’re in the past anyway, that there’s some kind of shame in losing a baby, which is ridiculous. But it’s just one of these things that, you know, when, when cultures change, our behaviors change slowly. I think a lot of women feel it’s their fault when they lose a baby, which is completely not the case. A lot of women, I know in my practice, a lot of my patients, if they do lose a baby, they ask questions like: What have I done? What could I have done differently? Is it because of that glass of wine I had when I didn’t know is pregnant?

I mean all of these things and I actively reassure them that no, it wasn’t their fault. That nothing they could have done would have changed the outcome and that they’re not to blame and that they’re very likely to go on and have a normal baby next time.

Interviewer: It’s a completely normal part of having a child, isn’t it? That she is having that miscarriage at some stage. So, if we look at a miscarriage, what are the steps to happen? So, you’re miscarrying, either happens organically or you go to the doctor and there’s a problem. What are the steps that happen with you when you’re miscarrying?

Dr. Raelia Lew: So some people learn that they’re losing a baby by having bleeding and the pregnancy resolving by itself. That’s quite a common experience, especially in the first few weeks of an early miscarriage. You can have biochemical pregnancy that ends in a miscarriage which means that you have a positive pregnancy test (maybe do the test a couple of days before your period due), and then you have your period either on time or one or two days late. So that’s a very early miscarriage.

Interviewer: So that could actually be that you’re pregnant and you don’t even know it and just you might have a slightly heavier period or maybe not even.

Dr. Raelia Lew: Yeah, and lots of people who have a clockwork menstrual cycle when they start trying might find that they have a cycle here and there that’s thrown a little bit out. That maybe they’ve had a bit of a longer cycle by a couple of days and that’s often because there has been, kind of conception, and sperm and egg have got together in the body and tried to implant but something’s gone wrong at a very early stage.

Interviewer: And, we don’t really panic when those happen because we don’t really know they’re happening?

Dr. Raelia Lew: Well and also, I think there’s a degree of emotional investment once women actively acknowledge that they are pregnant. And excitement about that even and much anticipation and happiness and you kind of have this projected thought of you know, yourself and you know, raising a child, and you know how things are going to be. So, when you lose a baby, it’s not just the physical loss, but it’s the loss of those expectations and the loss of those dreams.

Interviewer: It’s, you know, in a way, the end, like the end of any relationship where you saw a future and that future just got cut short.

Dr. Raelia Lew: Yeah. So that’s when a pregnancy spontaneously miscarries. Then there can be another category of miscarriage, which is known as in medical terms as a concealed or a missed miscarriage (I call it a silent miscarriage). When a pregnancy is lost, a baby stops developing, the baby’s not alive anymore, but there hasn’t been any bleeding yet.

Interviewer: Okay. So then, how’s that diagnosed?

Dr. Raelia Lew: Often it’s diagnosed on ultrasound. Sometimes a woman has a sneaking suspicion. A lot of people do when they have a silent miscarriage, they do have a feeling that it might be going wrong because sometimes pregnancy symptoms abate. So, sometimes there might have been feeling more breast tenderness or a little bit of nausea and that’s gone away so they haven’t had any bleeding.

Interviewer: Okay. So they’re starting to feel pregnant, then that feeling goes.

Dr. Raelia Lew: Yeah. So that can happen. But having said that, the feeling of pregnancy is very much to do with the chemical response to the pregnancy hormone called Beta HCG. And because that’s not made by the baby, it’s actually made by the growing placenta, the baby might have been lost, but the placenta and its tissue are still present. So, women can even still even feel pregnant when they’ve lost the baby.

Interviewer: Oh, that’s so sad. Okay. So let’s say this is the case and you had an ultrasound and we’ve identified that there’s no habit. Is that what will happen? So, what are the options?

Dr. Raelia Lew: It has to be confirmed that it’s definitely a miscarriage because sometimes we get our dates wrong. So, sometimes we might think that we’re six weeks pregnant and in fact we’re four weeks pregnant because ovulation happened a little bit lighter in that particular cycle or we’ve just miscalculated. So usually, if I see signs of an early pregnancy that could look normal, but just a week or two behind, then I’ll do another ultrasound a couple of weeks later for the patient. Just to confirm that we couldn’t be interfering with a viable pregnancy.

But the options for managing a miscarriage once it’s been diagnosed or a silent miscarriage, is to either wait. So conservative management involves just watchful waiting without intervention and you can do that for two weeks without increasing the risk of a woman getting an infection by doing nothing. After two weeks of conservative waiting, you really don’t want to keep waiting because a woman could get a uterine infection from a miscarriage that hasn’t been managed.

Interviewer: So, what we’re saying is that the fetus it has stopped growing? There’s no, there’s no life but it’s isn’t being ejected by the body and if it doesn’t happen naturally after two weeks, then you’ve got to intervene on a medical basis.

Dr. Raelia Lew: Yeah, we don’t have to as such but I would recommend it because an infection in the uterus will be something that can reduce your risk of having a healthy pregnancy in the future. That’s obviously not something that any woman wants in this circumstance.

Interviewer: Probably be quite painful and uncomfortable and have other effects too.

Dr. Raelia Lew: Yeah, and just emotionally as well, just, you know, it’s a saga that’s going on and on and on. And most women would at that point want to find some kind of resolution.

Interviewer: And be able to move on.

Dr. Raelia Lew: Yeah. There are some women who want to have active management from the beginning, from, as soon as it’s confirmed that it is a miscarriage and that’s fine as well. So I tend to put these options to my patients and I’m very much guided by their preference. Some women feel they just want to deal with things surgically because that’s really the only way where you can nearly 100 percent, you know, kind of guarantee that the it’s over.

Interviewer: Everything’s gone.

Dr. Raelia Lew: And it’s sorted out and you can move forward. Surgically managing a miscarriage involves emptying the uterus through an operation.

Interviewer: Is this under general?

Dr. Raelia Lew: Yeah, it’s a relatively minor operation, it is under general anesthetic. Usually I give a patient medication to make the procedure more gentle by letting the cervix dilate a little bit. It’s a similar kind of medication we used to induce a labor. It just makes the cervix softer and more kind of naturally dilating as opposed to forcing with an instrument. And then what we do for suction curate (which is what the operation is called), is gently dilate the cervix to about eight millimeters and place a little tiny flexible catheter (it has a plastic tube) inside the uterus and under section, remove the pregnancy and sack, and make sure the uterus is empty. Personally, I use ultrasound to double check that everything’s complete. Then the tissue from the pregnancy can be sent to the pathologist and a range of tests can be done on that tissue and sometimes it gives an answer to why there was a miscarriage. Not always, but sometimes it does.

Interviewer: So what would you be looking for in those tests?

Dr. Raelia Lew: I’d be looking for two things; one is histology, so that’s how the cells look under a microscope, and that gives me a clue as whether it’s a molar pregnancy, which is a type of pregnancy that will inevitably miscarry and that it’s important for me to know about to make sure that it’s resolved. It can tell me if there’s any infection that might have been associated with the pregnancy loss. Certain infections like Listeria or Salmonella can cause miscarriage.

The other thing that I send the products of conception off for – we call it products of conception, that means the tissue from a pregnancy – is a chromosomal test called a karyotype. Which I don’t do for every single patient, but a lot of my patients I would, offer them the option and that’s to look to say if the chromosomes that the babies have, are correct. Did they have the right DNA roadmap? Did that have the potential? If they followed the genetic instructions of becoming a normal baby?

Because if the answer is no, that can give a lot of understanding to a woman as to why the miscarriage happened.

Interviewer: Probably, especially if they haven’t had genetic screening before?

Dr. Raelia Lew: Yes and no. There’s two kinds of abnormal karyotypes. So, karyotype just means chromosomal number and chromosomal map. Chromosomes are the structures that our DNA is stored on, in every cell of our body. And the DNA is like the blueprint, if you like, of the instructions that are baby follows and the cell follows in any, any form of life to function in the normal way. So, it’s the instruction manual, and you can either have an abnormal instruction manual because when the sperm and the egg got together to make the embryo, there was some kind of imbalanced that was spontaneous.  So, it wasn’t from the mom and the dad, it’s just that it happened. It’s nobody’s fault. It just happens. It happens commonly. And the older we are, the more common it is that a mistake happens.

Or, there’s a very rare kind of DNA problem called a translocation or a new version. And that’s, it’s quite complicated, I’ll try and explain it simply. So, with our DNA, it’s not just the amount that has to be correct, but it’s also the way it’s arranged.

And a translocation is when a little piece of one chromosome is stuck on the end of another. So, it’s kind of a mistake structurally, but the patient or the woman or the man, could have the total amount of DNA. So, I’ve got the right total instructions but just kind of in the wrong order. But when we give DNA to our children, we only give them half of that DNA. Half from the mom and half from the dad.

Interviewer: So, if part of it is out of order or not constructed in the conventional way, and that’s the part that gets inherited by the child, that’s where the problem could be?

Dr. Raelia Lew: So, it might be what we call balanced in the parent, and that means that they’ve got the total right amount, but it can be unbalanced in a baby. And in couples who one of them, and it can be the dad (doesn’t have to be the mum), but when one of them carries an imbalance in their baseline DNA, they’ve got a balanced translocation but the DNA arrange in a slightly different way, they can make a high proportion of unbalanced egg and sperm. And they can make a high proportion of unbalanced embryos with their partner. That could mean that they’ve got a really high chance of having a miscarriage compared to anyone else. So, for example, where the baseline risk of miscarriage would be one in five, it might be that their baseline chance of having a normal baby may be one in five. So, that’s a very special form of miscarriage.

I’ve helped multiple patients in my practice with this particular problem, once identified by genetically testing embryos, before we put them back through IVF called pre- conception and diagnosis and then pre-implantation diagnosis of embryos. And then it achieved normal ongoing pregnancies for these couples and healthy babies.

Interviewer: So, whilst miscarriage is just unspeakably devastating, there could be some light found in the process.

Dr. Raelia Lew: When we find a reason for miscarriage, especially in recurrent miscarriage, and we find a reason for it, then it can be very powerful in that we can use technology to help couples go on to have healthy babies and to prevent further miscarriages. One of the other ways that we can use technology in women who have, not a predisposition to miscarriage because of a chromosomal abnormality, but just a predisposition because of their age. We mentioned that over 40 a significant number of babies will miscarry just because of spontaneous mistakes. Actually over 35 that will happen and that’s because the eggs have been with us for our whole lives and they get metabolically fatigued towards the end of our reproductive life. And from 35 –

Interviewer: So cheery.

Dr. Raelia Lew: Well it’s important to understand it because women, you know, blame themselves and think, you know, what have I done? When actually the egg has just made a mistake. And it can make a mistake in a young woman too, it’s common. But they’re more likely to make a mistake the older we are and certainly over the age of 37. If you’ve had more than a couple of miscarriages and we think the reason is that babies are just making mistakes, it’s a very reasonable thing to do, to consider going down an IVF pathway so that we can test embryos and put embryos in the bank, in the freezer, so that you might be able to have more than one baby down the track. Because if you’re having a great deal of trouble at 37, and you come back in your early forties wanting to have another baby. that can be even harder. But also that when we do put an embryo back, it’s far less likely to make a mistake and far more likely to be a healthy baby at the end of the day.

So, that’s another way that we can very powerfully intervene in a woman who’s had recurrent miscarriages.

Interviewer: So, what’s recurrent? Is that anyone who’s had more than one?

Dr. Raelia Lew: It’s one of those definitions that there’s a lot of controversy. Officially it’s more than three.

Interviewer: Oh, three.

Dr. Raelia Lew: Yeah but look, that’s the thing. I mean, certainly when I was in England in the NHS, the National Health Service there, you wouldn’t be investigated (it’s a purely public system), you wouldn’t be investigated for recurrent miscarriage causes unless you had three consecutive miscarriages. But I have to say in my practice, in a woman who’s had two miscarriages, I investigate. And in a woman who’s had one miscarriage but really feels strongly about it, I investigate.

Interviewer: So, just case by case basis, and other factors such as age and if we were using IVF, all these things will be taken into consideration.

Dr. Raelia Lew: Yeah and the things that we’re looking for in women who have recurrent miscarriage, so we talked about carrier types of chromosomal rearrangements, we look for that. We look for blood clotting problems, which can be either a priority, so they either have a blood clotting problem that runs in their family or in their genes, or they might have a blood clotting problem that’s acquired through autoimmune disease. They might have other autoimmune factors like thyroid problems that can be fixed.

And so, kind of taking their hormones and just getting it exactly right, getting the balance right. Sometimes weight loss because being overweight or obese is associated with miscarriage. So, lifestyle factors can be quite powerful and certainly women with polycystic ovarian syndrome, statistically speaking, are more likely to miscarry. However, most women with polycystic ovarian syndrome go on to have healthy babies.

So, you shouldn’t be frightened of recurrent miscarriage if you just have polycystic ovarian syndrome but if you look on paper, statistically it is more likely to miscarry in that category.

Interviewer: But then when you’re trying to get pregnant, you’d be speaking to your doctor about that anyway.

Dr. Raelia Lew: Yeah absolutely. Women with diabetes, having the sugar right, getting the sugar balance right, really reduces the risk of miscarriage and reduces the risk of having a baby with an abnormality, especially in the first trimester. So, I love to see my women who have diabetes, either type two, or type one diabetes before they’re even trying to get pregnant and work together to get the sugar right so that they’re not in the situation that they’re having recurrent miscarriages.

Interviewer: So, half the DNA comes from the father – can that impact on the pregnancy and cause a miscarriage?

Dr. Raelia Lew: Yeah, absolutely it can and we don’t even think about that as women, but it definitely can. So, if you take a woman who’s 40 and using a sperm donor – if you chose a 25 year old sperm donor, her chances of having a baby have better than if you chose a 45 year old sperm donor. And, so why is that? Well, as men get older, they acquire DNA damage in their cells.

Interviewer: So, it’s not just women who probably shouldn’t wait too long?

Dr. Raelia Lew: Absolutely. And while men make sperm their whole lives, so they’re not under the constraints of going through menopause, the sperm certainly deteriorates in quality as they get older. So, an older male is more likely to have a partner have a miscarriage. An older man is also more likely to have a baby with a series of different problems. So, for example, schizophrenia is more common in the offspring of older men. Autism spectrum disorder is more common.

Interviewer: Is it? So, it’s men, it’s not women.

Dr. Raelia Lew: Yeah well, we know that from research and also we know that it’s more likely to have a series of different DiNovo mutations in the DNA in the male sperm. Like for example a lot of people are familiar with Achondroplasia, which is a form of dwarfism. Of being a dwarf. So that’s much more common to spontaneously happen if your father is older. So, there’s lots of things that we know the DNA damage in sperm can contribute to risk of miscarriage. And that’s important because we know we can actually modify some factors.

Interviewer: So, what can I do to improve the DNA quality of his sperm?

Dr. Raelia Lew: There is quite a good body of evidence that using antioxidant therapy can help. So, antioxidants are chemicals or vitamins and minerals that maps out free radicals. So things like co Q 10 or vitamin C or vitamin A, melatonin are quite potent antioxidants. So often if I think a man has high DNA damage in the sperm I might prescribe antioxidant therapy. There are lifestyle factors, we know for example, that smoking does extra DNA damage to sperm and men who smoke have partners at risk of miscarriage more than other people.

So, ceasing cigarette smoking for three months before trying to conceive can seriously improve sperm. And also if I’m worried about a man’s sperm quality, then I’ll also look at his hormones and just make sure that things like his thyroid function are normal.

Interviewer: Okay. So, there’s things we can do on both sides?

Dr. Raelia Lew: Yeah, absolutely. And of course, not to forget healthy lifestyle, so diet is probably our best source of antioxidants, with fresh fruit and vegetables. Optimizing weight, reducing physical stress and also just looking after ourselves, getting enough sleep and being happy and healthy.

Interviewer: Making sure we have emotional support. So, we probably need to start thinking about miscarriage as an opportunity to learn something more about the process and what’s going wrong rather than thinking it’s, it’s our fault.

Dr. Raelia Lew: Yeah, we definitely shouldn’t blame themselves for undergoing a miscarriage. Important to remember that the women who have miscarriages are the same women who go on to have healthy babies 99 percent of the time.

Interviewer: This week when a friend asked me what topic we’d be covering on the podcast, I said miscarriages. And her response was, oh, why? And I said, because no one ever talks about them. And she was like, you’re right, they don’t. And I hope that this has helped a bit. Obviously we’re just starting as a culture to change the way we approach miscarriages and understanding why they happen.

For more information about Dr. Raelia Lew and her services. You can go to her website, Or you can email us on And you can find us on all the socials and Women’s Health Melbourne. Thank you for listening and we’ll see you again next week.


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