Can stress cause a miscarriage? Here's what fertility experts say.

There’s no simple way to explain why some women miscarry. There is no 'one size fits all' diagnosis, or one box you can put that kind of loss into.

In some cases, there’s no way to explain it all.

The unknown of miscarriage can be devastating, the void inside filled only by questions.

Was this my fault? What could I have changed? Why is this happening to me? Will it happen again?

Combing through every detail of the last however many weeks, some women might identify stress as the reason they were pregnant, but now no longer are.

The link between stress and miscarriage is complex. Both, sadly, are normal parts of being human. But are they related?

On the sixth episode of Netflix's Meghan & Harry, Prince Harry said he believes Meghan suffered a miscarriage as a result of stress caused by the British tabloids.

Meghan suffered a miscarriage in 2020, before she fell pregnant with the couple’s daughter Lilibet. At the time, the couple were embroiled in a legal battle with The Mail On Sunday, which published parts of Meghan's private letter to her father Thomas Markle. 

"I believe my wife suffered a miscarriage because of what the Mail did," Prince Harry shared in the documentary series.

"Now, do we absolutely know that the miscarriage was caused by that, of course we don’t.

"But bearing in mind the stress that caused the lack of sleep, and the timing of the pregnancy, how many weeks in she was, I can say from what I saw, that miscarriage was created by what they were trying to do to her."

Following Prince Harry's admission, here's what experts in obstetrics, miscarriage and pregnancy loss know about the role stress plays in pregnancy and miscarriage, and why the way we talk about it matters.

Can stress cause a miscarriage?

The first and most important thing you need to know about miscarriage is it is very common. We know up to 25 per cent of all pregnancies end in miscarriage.

They may occur in private. They might go unnoticed by outsiders. But they’re happening to women every day.

Dr Devora Lieberman is a fertility expert who specialises in managing recurrent miscarriages and IVF. She explained pregnancy loss is a devastating, but ultimately normal part of human reproduction.

"One in four pregnancies unfortunately won’t make it to term. That doesn’t diminish the sadness, or anger, or grief a woman might feel. But it is normal," Dr Lieberman told Mamamia.

"There is nothing that a woman can do that would cause a pregnancy to fail. It goes the other way too, there’s nothing you can do to stop it from happening."

Dr Lieberman has seen many women blame themselves after suffering a miscarriage, convincing themselves if they had been less stressed or done more, this tragedy could’ve been avoided. It’s a myth she’s spent her career, spanning decades, trying to fight.

"Miscarriages are emotionally stressful. They can cause stress, but stress does not cause miscarriage. If a woman is already pregnant, stress will not impact on that woman’s ability to carry their baby to term.

"It’s really important women understand that when a pregnancy fails, there’s nothing they could have done to stop it. Women blame themselves, they feel somehow responsible when a pregnancy fails. They can feel guilty and angry, and make themselves feel far worse than they already do.

"Stress is very much a part of everyday lives – stressful relationships, finances, jobs – I don’t know it’s possible to avoid it. Stress isn’t healthy for a woman’s [mental health], but it’s not going to have an impact on her ability to get or stay pregnant.

"There’s nothing you can do to prevent a miscarriage once you’re pregnant."

From a research perspective, Melbourne-based obstetrician and gynaecologist, Dr Joseph Sgroi agreed there’s not enough data to determine that an increase in stress or a stressful, traumatic event can cause a miscarriage.

"Unfortunately, there’s not a lot of data into this. Yes, we acknowledge people under a lot of stress might find it difficult to conceive, but in relation to miscarriage, we can’t," he told Mamamia.

"It’s difficult to tease out, in particular because what is stressful for you is different for someone else. There are plausible associations between maternal stress and going into preterm birth (birth that occurs before the 37th week of pregnancy), but whether stress can definitively cause a woman to miscarry is near impossible to demonstrate because we can’t subject pregnant women to stress and others not in order to find out.

"Should a woman be concerned if she’s gone through a major upheaval in terms of miscarrying? The fact is there’s not enough data to support a conclusive correlation. Even in heightened, stressful situations in war-torn countries, women still conceive and give birth where there’s stress 24/7. That doesn’t diminish any individual’s stress or anything someone is going through, but it does add context because people can continue to conceive and have children under those conditions.

"Conversely, we see patients who try to mitigate stress by doing yoga and meditation, and practising mindfulness that sadly experience the same outcomes. That’s why we look into the other reasons this may have happened."

SANDS, an organisation that provides miscarriage, stillbirth and newborn death support, also acknowledged there is no evidence that stress, along with exercise, working or having sex during pregnancy cause miscarriages.

What this means for anyone who has miscarried is, it is not your fault. You are not to blame for this tragedy.

Other causes of miscarriage.

If not stress, what are the other reasons that cause women to miscarry?

"When we’re trying to identify why a woman miscarried, what we’re doing is looking back through the pregnancy for characteristics that might have caused miscarriage or preterm birth," Dr Sgroi said.

Every patient is different and needs to be assessed as an individual, but generally speaking, there are four common factors specialists look into.

Chromosomal issues.

Both Dr Lieberman and Dr Sgroi cited abnormalities in an embryo’s makeup as the most common reason a pregnancy ends in miscarriage.

"When an embryo fails, it’s because there’s something wrong with it. About 75 per cent of the time, it will be because of a chromosomal abnormality. Pregnancy is a very strong filter of the abnormal – in other words, if an abnormal embryo manages to implant in the uterus, it generally won’t be able to hang on for very long," Dr Lieberman said.

Dr Sgroi continued, "It’s the biggest, and by far, the most common reason for a miscarriage. If there’s an additional chromosome or a subtraction and the embryo doesn’t have a full complement, that can lead to a miscarriage. Pregnancies can continue [with chromosomal abnormalities]. For example, an excess chromosome can lead to down syndrome."

More often than not, an embryo’s ability to develop properly is spontaneous, not inherited.

"Think about all that has to happen for a tiny clump of cells to become a baby with 10 fingers and 10 toes, with everything where it’s meant to be. It’s an amazing thing, but sometimes things go wrong with that process," Dr Lieberman said.

Medical history.

A patient’s medical history can have an impact on whether a woman miscarries, but not always.

"Your genetic, hormonal profile is a factor we consider, like having a low or underactive thyroid or diabetes. There are some autoimmune conditions where the body’s antibodies can potentially attack the pregnancy in its early stages," Dr Sgroi said.

Structural issues.

A physical problem with the structure of your uterus and/or cervix can lead to a miscarriage.

Dr Sgroi explained your uterus is similar to the inside of a ball or a balloon. If there are partitions blocking space, or rough surfaces caused by fibroids (non-cancerous growths in the uterus), these can cause miscarriage as well.

Age.

"We know the biggest risk factor for miscarriage is increasing age. As we get older, an ever-increasing number of our eggs aren’t normal, which results in abnormal embryos that won’t make it," Dr Lieberman said.

"For a woman in her early 30s, she’ll have 15 to 20 per cent chance of miscarrying. At 40, it’s around 50 per cent, and beyond 45, upwards of 90 per cent."

Can miscarriages be prevented?

As Dr Lieberman said, there is nothing a woman can do to prevent a miscarriage once she is pregnant. You can take steps to increase your chances of conceiving a healthy embryo, but again, there comes a stage where things are out of your hands.

Stress, for example, won’t cause a miscarriage but if your stress is so severe it’s impacting (or stopping) your menstrual cycle, it could have an impact on your fertility.

Both experts said ensuring you and your partner are as healthy as you can be is advised if you’re thinking about starting a family.

"For anyone contemplating having a baby, it’s important to contemplate this at a time when you’re physically, mentally, financially and socially able to do so. Part of that includes being in a good health state physically and mentally," Dr Sgroi said.

Dr Lieberman added, "It comes down to lifestyle factors – being overweight increases the risk of infertility or miscarriage, as does smoking."

They also advised to make sure any conditions that might increase your risk of miscarrying (autoimmune diseases and diabetes) are being properly managed under the advice of your healthcare professional.

Why the way we talk about miscarriage is important.

Talking about miscarriage is important and should never be underestimated. Only by hearing and learning about the experiences of other women can we gain perspective on our own, and begin to heal.

Mental health professional and SANDS General Manager of Bereavement Care Anita Guyett explained the way we talk about the traditionally taboo topic is equally important.

"Whenever you go through a miscarriage, it’s incredibly stressful. The grief that comes from that is kept behind closed doors and you don’t always get to speak to anybody about it. It’s important to lift the lid and remove the taboo of miscarriage, but we know subsequent pregnancies after a miscarriage in the past carry a lot of unanswered questions," she said.

"Particularly if you don’t know why you had a miscarriage – most miscarriages are unexplained and some may never know why it happened. There’s a lot of angst in not knowing what went wrong last time and if it will happen again."

It’s normal for tragedies to make us question and search for an answer. When things go wrong, we want – sometimes need – someone to blame. Most commonly, women blame themselves, even when it is likely out of their control. This is why it’s important not to label things before seeking professional advice, Dr Sgroi said.

"The biggest thing with miscarriage is the why and working out why this happened. And you can. Yes, it’s ‘nice’ to have an idea of what went wrong, but it is also dangerous because it could be something else. A lot of what we internalise might not be the true, identifiable cause.

"Part of figuring out the why is seeking guidance from a professional. Go and speak to a doctor or specialist who is supportive of you and you can try to work out why the miscarriage occurred. From there you can explore if there’s something that can be done in terms of preventing another miscarriage.

"Self-blame only perpetuates that feeling of shame and guilt associated with having a miscarriage. Hopefully hearing about miscarriage more often can help alleviate a small part of that anxiety."

Guyett also stressed taking care of your mental health after a miscarriage, or when trying to conceive again, is crucial.

"There are a lot of women out there who might be feeling triggered with stories in the media. We know hearing about something in any mental health space, including miscarriage or pregnancy loss, can be triggering. That is why it’s so important that we make parents aware that there is professional help out there so that if you are getting those triggers or you are concerned about your pregnancy, there is somewhere you can turn.

"You might feel a lot of fear for the next pregnancy [after miscarrying], that fear quite often won’t go away until the baby is born, and that’s very normal. I guess we would ask women reach out, have that conversation, a lot of the time women don’t know that fear is what they’re feeling, and that it’s normal."

The key message experts want women to know, again, is that miscarriage is normal. It’s also, again, not your fault.

"It makes me so upset when women blame themselves," Dr Lieberman said.

"I know that when you have an ultrasound and you don’t see a heartbeat, you’ll go through every minute of everyday of your pregnancy and think 'it was the heavy thing I picked up or the fight we had, or the glass of wine I had before I knew I was pregnant'.

"But none of these things will cause a pregnancy to fail."

This post was originally published on May 2018, and updated with new information on December 16, 2023.

If you or a loved one is suffering after pregnancy loss or miscarriage, please seek professional help and contact SANDS on 1300 072 637 or support@sands.org.au, or Lifeline on 13 11 14. If you are in immediate danger, call 000.

Feature Image: Netflix.