Miscarriage Myths

I was recently asked to comment in a Sun Herald article on 26th August (also published online here: Sydney Morning Herald) on Collette Dinnigan, who pregnant at the age of 46, has called on women not to leave it too long to try for a baby.

It is always news when a high profile personality such as Ms Dinnigan, has a child, particularly when the personality in question is a bit older.  The difficulty is that these occasions, while very happy for the people involved, give a misleading picture of the actual likelihood of conception in these circumstances.  Remember that high profile personalities such as Ms Dinnigan, are human beings who quite rightly value their privacy and so very rarely (quite understandably) talk to the press when things aren’t going so well.  It was therefore, a particularly courageous action of Ms Dinnigan, while celebrating her own happiness, to so publicly, point out the difficulties that may face other women, seeking the same fulfilment.

What then, are the issues for women in their forties who are planning to have a child?

The main difficulty is that conceiving is simply harder at that age and, even once a woman does conceive, the risk of miscarriage is higher.  Surprisingly, although we have very good data about the effects of age on IVF conception (more shortly), we don’t have very good statistics about the effects of age on conceiving naturally. The limited available data about natural conception comes from old population studies or studies of unique populations, such as the Hutterites of North America, who do not use contraception.  Interestingly these data, such as they are, seem to be entirely consistent with the more modern and abundant IVF data.  Generally, in one year of trying, 75% of women under 30 years and 66% of 35-year-old women but only 44% of 40-year-old women will achieve a live baby naturally.

The main explanation for this, is that women are born with a finite number of eggs, and from that moment onwards, the number of eggs is declining all the time, until women go through their menopause at around 50-51.  Nonetheless, women in their 40s do still ovulate each month.  What is it about their eggs that cause all these problems?

A common misunderstanding with some women is that the fact she looks and feels young, and leads a healthy lifestyle, means that her eggs will be healthier. I regularly see women who have taken enormous care with their fitness and their health.  The rest of their body is in great shape, completely fit and ready to carry that longed-for pregnancy.  Sadly, despite this, the eggs still can’t do it.  The effects of time are remorseless and, sadly, there is no wonder drug to fix it.

Scientists have shown that eggs from older women are more likely to have an abnormal makeup making pregnancy less likely, miscarriage more common and increasing the risk of Down Syndrome, a condition where a child is born with an extra chromosome number 21.

Nor is IVF a cure for this problem. For women, in their early 40s, IVF is still a good thing to try and gives significantly higher success rates than trying naturally.    However, IVF success rates fall sharply after the age of 40 and by the time a woman is 45 are close to zero.

So, what’s the good news?  Well despite all of the above, many women do conceive in their forties, either by IVF, or naturally, and have very happy healthy families.  It is obviously better to have your family earlier, if you can, but all hope is not lost, just because you’re past 40.  Conception and early miscarriage are the big problems but, if you do conceive and get past the first few weeks, by far the most likely outcome will be a healthy child.  While the risk of Down Syndrome is increased, most of the other problems that affect young children are not increased by being conceived a later maternal age.

Finally, many women worry that by having their children later, their long term health and emotional development may be affected.  On the contrary, we now know that the children of older mums grow up to be as healthy and bright as any other child.

How much do you know about your fertility? Is having a family something you’ve considered, but haven’t really given much thought to?

As Australia’s leading fertility specialists, we know all too well the impacts of women trying for children too late – especially considering that a woman’s age is the number one cause of fertility issues. But for many, high school was the last time they received any education about their fertility, and the focus then is generally on what to do so you DON’T fall pregnant.

For this reason, we commissioned a study amongst women of reproductive age to find out if they really understand their own fertility. 
Some of the results may surprise you:

• 64% of respondents didn’t know their fertility rapidly declines from the age of 36
• 60% believed infertility in their 40’s would be easily resolved if they underwent IVF
• 20% incorrectly believed it only became difficult for a woman to fall pregnant naturally in her late 40’s
• 80% knew a pregnant woman in her late 30’s and early 40’s had an increased risk of having a baby with chromosomal abnormalities, however 42% did not know this age group also has an increased risk of miscarriage
• 92% of women knew that being overweight could affect their fertility
• 74% knew that excessive alcohol consumption could also affect their fertility

Is there a lack of understanding about fertility?

There appears to be a critical information gap about how a woman’s age and egg quality affects her fertility and chance of falling pregnant. As an example, at 30, when trying to conceive, a woman has a 20% chance of falling pregnant in any given month, compared to less than 5% chance when she is in her 40’s.

It’s a real misconception that women can delay motherhood until their late 30’s and rely on IVF to easily resolve their problems and conceive well into their 40’s. Although IVF is very effective and may dramatically improve a woman’s chances of having a baby – it is not a guarantee.

Unfortunately, the effects of age on a woman’s fertility cannot be reversed.  As a woman ages so do her eggs, and it is not possible to improve the quality of a woman’s eggs – which impacts her chance of conceiving both spontaneously and with IVF.  The increase in media stories of celebrities having babies in their mid-40s has given people a false sense of security as to how age impacts their fertility.

But, it’s not all bad news.

The survey results did demonstrate that women are well informed regarding lifestyle factors impacting their fertility such as weight and excessive alcohol consumption.

While we can’t do anything about the impact age has on a woman’s fertility, we can provide women with the facts about how their age and health affects fertility, so that even if they’re not ready to start their family now, they make informed decisions about their future.

For example, it might be a good idea for women who are concerned about their age and are wondering about their fertility window to consider an AMH test, or Anti Mullerian Hormone Test. Otherwise known as the ‘egg reserve test’ or ‘egg timer test’, this simple blood test can provide insight into the remaining quantity of eggs and number of fertile years you may have, but it cannot tell us much about the quality of those eggs.

Learn more about the AMH test by contacting your GP or fertility specialist. 

Find out more here:

For NSW
For VIC
For QLD
For TAS

The survey of 1038 Australian women aged 18-55 was conducted by Research Now, April 2014.

One significant development in assisted reproductive technology (ART) in the last 25 years is our ability to remove cells from a developing embryo and perform genetic testing. The procedure is termed preimplantation genetic screening or preimplantation genetic diagnosis depending on its application.

As technology has improved we have seen the use of PGS and PGD in IVF rise, with the latest Australia and New Zealand Assisted Reproductive Treatment Database (ANZARD) reporting a 20% increase.

What is Preimplantation genetic screening?

Preimplantation genetic screening (PGS) or ‘embryo screening’ is a method where embryos from presumed chromosomally normal genetic parents are screened for abnormalities. It involves screening all 24 chromosomes in a developing embryo to select the embryo/s without any chromosomal errors that is most likely to result in an ongoing pregnancy.

PGS is an evolving technique that is now recognised more arguably as a way to improve pregnancy rates in women experiencing repeated IVF failure and recurrent miscarriage.

What is Preimplantation genetic diagnosis?

At this stage of medical science we are not able to routinely ‘screen’ embryos for faults in the 20,000 or so genes located on our 23 pairs of chromosomes. Therefore we cannot tell if an embryo is destined to develop a particular genetically inherited condition unless we are specifically looking for it. This is known as Preimplantation genetic diagnosis - PGD for short. Some couples may require this when there is a known genetic condition that runs in their family, such as Huntington’s disease, Cystic fibrosis, Thalassaemia and Fragile-X.

How is PGS & PGD performed?

Both PGS & PGD involve taking cells from a developing embryo usually at the day 5 (blastocyst) stage. This step is called an embryo biopsy. The biopsied cells are then tested to assess the embryo and health of any potential baby. The embryos are frozen whilst we wait for the results. The embryo then determined to either have no chromosomal errors (PGS) or be of low risk for the genetic condition we are testing for (PGD) is transferred back into the woman’s uterus.

Embryo selection in an IVF cycle

During an IVF cycle, selecting an embryo for transfer has traditionally been based on appearance alone, called morphology.  A ranking of which embryo is likely to result in a baby, based on an appropriate number of cell divisions at a given time is established. Then, each month, the next best embryo is transferred into the woman’s uterus. Unfortunately, many embryos do not result in a baby. The reasons for this are mostly related to genetic factors of the embryo and not the uterine environment.

What causes an embryo transfer to fail?

There are many reasons the transfer of an embryo does not lead to an ongoing pregnancy. An important requirement for an embryo is that it is genetically normal and has 23 pairs of chromosomes, which are labelled 1 to 22. There are also 2 sex chromosomes, XX (female) or XY (male).

Sometimes an embryo can have an extra chromosome, such as three copies of chromosome 21, which we call trisomy 21. This embryo would be destined to have Down syndrome. If an embryo is missing a chromosome, for example chromosome 4, we call this monosomy 4. These major structural errors, also called aneuploidy, commonly lead to a negative pregnancy test or result in miscarriage.

How common is it for an embryo to be genetically abnormal?

We know that approximately 30% of embryos from women aged 30 have genetic errors and this rises to 80% of their embryos at the age of 40. The reason for this is due to the ageing process that inevitably occurs in the egg. 

Women are born with all the eggs they will ever have and as a woman’s eggs get older, these errors become more frequent. Unfortunately, even the best embryos based on their appearance can have these errors. The result is that most of these embryos when transferred will result in a negative pregnancy test or miscarriage. This is largely the reason that the chance of pregnancy declines as women get older. The chance of miscarriage also increases for the same reason. At 30 years, 1 in 6 pregnancies end in miscarriage. At 40 years, this has risen to 1 in 3 pregnancies.

How can embryo screening increase pregnancy rates?

When we identify and exclude abnormal embryos from transfer, the likelihood is that the time to achieve an ongoing pregnancy will be reduced. Fewer procedures and less dreaded two week waits make IVF treatment easier.

It’s important to remember that transferring an embryo without genetic errors does not guarantee a pregnancy. An embryo must also be normal in other ways that we cannot test for.

Who could benefit from embryo screening?

Women recognised to benefit from embryo screening are those experiencing recurrent miscarriage or implantation failure. There is also increasing evidence to support the use of embryo screening for women 38 years and older. 

Since the embryo screening process involves comparing embryos to see which one is more likely to lead to a successful pregnancy, it is more appropriate for couples that have more than two day five (blastocyst) embryos.

What can I do next?

If you have questions about PGS or PGD, consult a fertility specialist. They will be able to advise whether the technique is appropriate for your situation and answer any questions you might have.

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