Older women face a lower chance of fertility treatment working, even when using young donor eggs – with a marked drop-off from around the age of 49, new research suggests.
Experts studying 1,774 women say the findings challenge the idea that donor eggs can fully “reset” the reproductive clock, but should not put older couples off trying.
Women aged 49 and over had double the risk of miscarriage than those aged 35 to 40, and were also less likely to get pregnant.
Researchers believe age-related changes in the womb lining may be the cause and could be treatable in the future.
It might be possible to find ways to predict, prevent or improve womb age, they say.
Lead researcher Dr Beatrice Crestani, from an assisted reproduction medical institute in Italy, external, says that reproductive ageing has been seen as an ovarian issue, and that if you replace older eggs with younger donor ones, you “reset” the reproductive clock.
“Our findings suggest the picture is more complex,” adds Dr Crestani.
In the study, women in their mid to late 30s had a 54% chance of getting pregnant with donor eggs and IVF treatment; that fell to around 43% for those aged 49 or older.
Live birth rates declined from 46% to 32%, while miscarriage rates increased from 24% to 38%.
The researchers also noticed age-related changes to the womb lining or endometrium – where a fertilised egg or embryo implants to grow – in the older women.
While the thickness was similar, the condition declined with age.
Dr Crestani added: “These findings should not discourage women from pursuing donor-egg treatment, because success rates remain meaningful even at advanced ages.
“However, patients should be counselled that donor eggs cannot completely eliminate the effects of reproductive ageing, particularly beyond 49 years.”
In the study, the live birth rate was around 80% for women aged 35-40 and 62.5% among those aged 49 or older who transferred all available embryos.
This Morning’s TV soap expert Sharon Marshall went through six years of IVF attempts in her 40s. At 46, she gave birth to her daughter Betsey.
“We look at celebrities who have given birth in their late 40s, early 50s and beyond. We celebrate them. We don’t know what hell they’ve been through.
“Looking back I think I spent most of my 40s really in a state of illness and depression and it was a complete loss of autonomy over my body. I was going through this process over and over again.”
She says she had made a pact with herself to quit at 47 if the IVF didn’t work by then.
“We had two losses before we finally got there on the seventh round,” she recalls.
Marshall says she worried throughout the pregnancy. “I never once felt calm… until the point she was born.”
Speaking about the new study findings, she said: “Let’s be honest with women about the difficulties they may face, about how hard it can be to get pregnant when you get older.
“We deserve to know that.”
Image source, AlamyExperts stress the health of the womb and ovaries differs from woman to woman.
There is no legal upper age limit for IVF in the UK, unlike some other European countries, such as Greece, which has a cut off of 54.
In the UK, women up to the age of 36 are able to donate or share their eggs.
Regulators, external do ask private UK clinics to assess the welfare of the resulting child and the physical ability of the recipient to carry a pregnancy safely.
Guidelines for the NHS, meanwhile, recommend that women up to the age of 40 should be offered three cycles of IVF and women up to the age of 42 should be offered one cycle of IVF.
Patients who use donor eggs usually have to self-fund that part of the process.
In the UK, people conceived using donated sperm, eggs, or embryos from registered donors after April 1 2005, can now request identifying information about their biological donor parent once they turn 18.
The study findings are being presented at the European Society of Human Reproduction and Embryology (ESHRE) and are published in a medical journal, external.
Commenting on the work, Prof Borut Kovacic, Chair-elect of ESHRE, said researchers are trying to better understand the “cross-talk” that happens between the implanting embryo and womb lining.
And while this latest study identifies an age threshold associated with the beginning of loss of uterine function, it was unlikely to be absolute.
“It provides important information for patients and offers a valuable foundation for future research aimed at identifying novel biomarkers of uterine ageing,” he added.
Dr Ippokratis Sarris, chair elect of the British Fertility Society, recommended more research and said pregnancies could be riskier for older women, meaning couples should have thorough checks and counselling when embarking on fertility treatment.
-
26 July 2018
