IVF still can not roll back the biological clock

PATIENT POPULATION OF IVF IS AGING

The most crucial thing to know about IVF is that it is now addressing a different population than for which it was created.

In the beginning, it was invented for couples with blocked fallopian tubes, or weak or defective spermatozoa. Louise Brown's mother, Lesley, who was 30 when she gave birth, had blocked the fallopian tubes. Most patients in the 1980s and early 1990s fell into this category, with an average age of 25 years.

This quickly changed. Of the eight million babies born in the world since 1978, two-thirds were born after 2007. And 90% of IVF mothers in the last decade were in their thirties, having tried and failed to conceive naturally, or have begun their fertility journey tardily. 19659002] In fact, the rate of women over 42 who start IVF increases six times faster than their 30s, according to the Society for Assisted Reproductive Technology (SART).

This changes the name of the game – the fertility innovators explore all sorts of options, from embryo editing to in vitro gametogenesis (or, IVG, which could make eggs from human skin on any part of the body).

"The patient population is different from what we initially treated," says Dr. John Zhang, of New Hope Fertility Center, at DailyMail.com.

"The people who come to the party are completely different.It is completely different.And you know what ?: You can not serve the same food or the same drink to a different crowd at any one time. different feast.You can not.

HOW WORKS THE FERTILITY OF A WOMAN

A woman has all the eggs that she will have in 20% of her pregnancy in the Uterus – about two million – and after birth, she begins to atrophy.At puberty she has an amount of $ 300 000.

Only a fraction of these eggs are raised for fertilization During her lifetime, the average woman will only mature 400 eggs for sperm to inseminate – usually one egg per cycle.

While sperm can live for up to a week in the uterus, the mature eggs have only one day.If the sperm does not strike within 24 hours, the The egg dies and floods with blood accumulated on the walls of the uterus as a cushion for a fertilized egg to implant and begin to grow.

Louise Brown's mother, Lesley, who was 30 years old when she gave birth, had blocked the fallopian tubes which prevented her from conceiving

Generally, at the age of 42, a woman stops laying eggs for fertilization. That's not to say that she has no eggs to fertilize a sperm. But the chance that these eggs are genetically normal and able to develop into a baby is slim.

"Age can not be underestimated. That's the determining factor, "says Dr. Zev Williams, MD, head of the Division of Reproductive Endocrinology and Infertility at Columbia University Medical Center, at DailyMail.com

]. Yes. The chances of a viable pregnancy, however, are low. The woman might not even know that she was pregnant or it could be an early loss.

"The big difference is the probability that the egg is chromosomally normal [i.e. that all 24 chromosomes are fine, which is key for development].

"If you take 10 embryos from a 25-year-old woman and test them genetically, 60% would be normal. A 42-year-old man may have one that is chromosomally normal. It's a big difference.

SO WHAT ARE THE FIGURES OF AGE AND FERTILITY?

When it comes to age and fertility, there are many numbers circulating and reporting.

In general, most practitioners – and SART statisticians – agree on these numbers:

• In one year, women under 40 years of age have an 80% chance of conceiving in one year [19659032] According to the IVF cycle, women under 35 have a 48.5% chance of recovering viable eggs
• According to the IVF cycle, women over 40 have a 3.2% chance to Recover Viable Ova
• Under 35 years of age, 60% of an IVF-fertilized female embryo must be "chromosomally normal" (with no defect in any of the 24 chromosomes)
• More 40, 10% of their embryos will be chromosomally normal

IVF meant that any woman younger than 42 years old could have an 80% chance of conceiving in a year, and we could even examine the embryos before they were implanted, which means that babies are healthy – far from supernatural aliens the 70s.

THE FAMOUS STUDY THAT CHALLENGES THE "MYTH OF T HE BIOLOGICAL BELL – AND WHY REQUIRE A SALT SALT

A 2004 study, recently cited in an episode of the hit show Adam Ruins Everything, calls into question the idea that a "biological clock" of a woman approaches the end of her fuse after the age of 35.

The study, by the National Institutes of Health in 2004, revealed that "many infertile couples will conceive if they try for an extra year."

The lead author, Dr. David Dunson, of the Biostatistics Branch, found that a woman has as good a chance of conceiving at age 37 (82% in one year) that 32 years old (86%).

However, while the show stated that it was a proof that women in their late thirties and early forties may have viable pregnancies, that was a slight extension of the Dr. Dunson's conclusion.

Dr. Dunson found that there is a difference between infertility and infertility as we get older. Most women, he discovered, become progressively infertile over time (less able to conceive without a year of unprotected bad).

However, despite what some have suggested, he insisted that women over 40 do not necessarily become sterile (completely unable to conceive without badisted procreation)

According to Dr. Jennifer Mersereau, Associate Professor at the Department of Reproductive Endocrinology and Infertility at the University of North Carolina, this is one of the biggest confusions she sees in patients .

"The big [misconception] is the effect of age and maternal outcomes," she tells DailyMail.com. ] "Really, many patients do not understand that the chances of conception drop so dramatically that you get older, even with IVF.

"They see movie stars getting pregnant at age 45, so they badume we can all do that, people are very upset when you tell them that for most people it does not work like that

IS THE PREDICTION OF SUCCESS BETTER?

Nowadays, the predictions of IVF are much clearer than they were there. 40 years old, but we still can not say it will be a success.

There could be two 35 year old women with exactly the same lifestyle, BMI and IVF background – and a doctor could not say for sure if one or the other would succeed in one round, two rounds, three rounds, more rounds, or ever.

According to Drs Zhang, Williams and Mersereau, this will not change anytime soon.

Age is still the determining factor, but it is so variable depending on the cycle of each woman. [19] 659002] # If you want to know by cycle, or by month, it's very variable. It depends entirely on the individual, "says Dr. Zhang.

MODERN TECHNOLOGY THAT CAN DODGE THE LIMIT OF AGE

" If you want to have a baby with your DNA, there is no age limit, "says Dr. Zhang for pioneering nuclear transfers (the" three-parent babies "who use the DNA of A donor, as well as the DNA of mom and dad to eliminate hereditary diseases).

Asked for a number, he said "no limit" means "no limit." In theory, we could to make babies using 85-year-old DNA in a laboratory setting.

"From our understanding of the fundamental biology of reproduction, it is highly likely that women can have a baby at home." the age that they desire.

"If you want to carry the baby, that is to say deliver a baby, this limits the age

After the age of 42, there are some options.

One option, which should become more and more common (as our story explains), is that a woman could use eggs or embryos that she froze years ago.

Another, that is, she could use eggs or embryos.

Then there are the most controversial technologies.

There is the prospect of IVG (in vitro gametogenesis), which is the creation of human eggs containing a person's DNA using cells taken from n & # 39; Anywhere, from cheek to arm.

for wider acceptance of its pioneering nuclear transfer technique (see box below for more details). The technique, dubbed the "three-parent baby," uses the DNA of the mother and father, as well as that of a donor to edit the embryo to suppress hereditary diseases.

For these latest technologies, there is no dearth of criticism

"I think these new technologies like nuclear transfer where there are three parents in a cell of the future baby is really unexplored territory "Dr. Mersereau warned.

"No human develops naturally this way. We really do not know what the long-term effects will be for a child. It's really different from the fertility care that we currently have. Most countries and companies say that it is really interesting but we have to take it with extreme caution.

Dr. Zhang is, of course, more relaxed about this. He insists that these companies are essential to give all women the option of motherhood.

He believes that the current controversy about these techniques is comparable to the controversy over IVF in the 1970s – and if only we can land on the right wording, things will get better ("I hate to use the word" artificial "or" hybrid ", it scares people.)

In fact, he says that most of the patients to whom he desperately addresses these developments are advancing faster, although governments are drawing leaves on any research.

But he insists that he believes that it may not be ethical to push motherhood beyond the 39, age of retirement.

"It's a little different if you look at it from an ethical point of view." Ethics and socioeconomics must be taken into consideration because if a mother has a baby at age 85 – which, I think, is no problem biologically – you will have this baby at the adol escence when the parent is dead.

The Nadiya clinic in Kiev, Ukraine, performs a procedure where the DNA of three people is used to create babies for couples struggling with infertility. On the photo: the director of the clinic Valery Zukin holding a baby girl born by this procedure in January 2017