FERTILITY TREATMENT

Embryo vitrification is safe but longer storage reduces chances of pregnancy success

Embryo vitrification is safe but longer storage reduces chances of pregnancy success

Freezing and storing embryos during fertility treatment using a technique called vitrification is safe, although women are less likely to become pregnant and have a live birth the longer the embryos are stored, according to new research published in Human Reproduction, one of the world’s leading reproductive medicine journals.

There have been concerns that vitrification technology could be unsafe for the embryo, leading to complications at the time of birth and later, including preterm birth, low or high birthweight and birth defects.

Until now, it was also unclear whether storage time after vitrification affected embryo viability, pregnancy outcomes or neonatal outcomes. The study, which is the largest to investigate these questions, found that the chances of becoming pregnant and giving birth to a live baby significantly decreased with longer storage time.

The researchers from the Shanghai Ninth People’s Hospital (Shanghai, China) analysed outcomes from 24,698 patients who had vitrified embryos transferred for the first time between January 2011 and December 2017.

They compared patients who had vitrified embryos stored for up to three months (group one) with patients whose embryos were stored for 3-6 months (group two), 6-12 months (group three) and 12-24 months (group four). They found that the implantation rate fell from 40% in group one to 26% in group four; the clinical pregnancy rate fell from 56% in group one to 26% in group four; and the live birth rate fell from 47% in group one to 26% in group four.

This means that among women who had embryos stored for less than three months, 47 out every 100 women would achieve a live birth. Whereas among women who had embryos stored for between 12-24 months, 34 out of every 100 women would achieve a live birth.

The rate of miscarriages and ectopic pregnancies also increased with longer storage time. However, these associations were not statistically significant after taking into account factors that could affect the results such as the mother’s age, mother’s body mass index, the cause of infertility, parity and embryo quality and stage of development. There was no evidence that storage time affected neonatal outcomes.

Groups three and four had a greater proportion of older women or patients with a poor prognosis due to smaller numbers of available eggs than groups one and two; so the researchers carried out a second analysis to investigate whether it could be the women’s ages and the amount of viable eggs they had in their ovaries at the time of vitrification and embryo transfer that led to the lower pregnancy and birth rates.

They analysed a subset of 7,270 women who were younger than 36 years and whose infertility was caused by blocked or damaged fallopian tubes. This produced similar results; there was a 50% live birth rate among women in group one, compared to a 38% live birth rate in group four.

Dr Qianqian Zhu is a research assistant who led the study. She said: “We think the results from this sub-analysis support our main results about the relationship between the duration of storage with pregnancy and neonatal outcomes.”

Co-author, Professor Qifeng Lyu is deputy director of the department of assisted reproduction at the hospital. He said: “Our study suggests that although the storage time of vitrified embryos negatively affected pregnancy outcomes, including clinical pregnancy and live birth rates, it did not affect neonatal outcomes. Concerns have arisen over the safety of prolonged storage time of vitrified embryos worldwide following the wide application of vitrification, and neonatal health is related to growth, development and health in childhood, adolescence and adulthood. Our study demonstrated the safety of using long-stored embryos after vitrification on neonatal health.

This is reassuring news for couples seeking fertility treatment. The reduction in live birth rates can be overcome through additional embryo transfer cycles. If we had found that neonatal health was adversely affected by vitrification, it would impose a heavy burden on individuals, family and society.”

The study is unable to show the effect of storing embryos for longer than 24 months, and the researchers did not undertake long-term follow-up of babies, so do not have information about their growth and development. As the study was retrospective, the researchers say that prospective studies with long-term follow-up are needed to investigate the safety of vitrification for longer periods of time.

Dr Zhu said: “Our results suggest that clinicians should consider the effect of storage duration before making decisions about the numbers of embryos to freeze and store. This is especially important for cancer patients, who may have their ovaries destroyed by cancer therapies and who have to delay fertility treatment until they have recovered from their disease.”

Vitrification involves placing embryos briefly in a solution to dehydrate them before they are rapidly frozen into a glass-like state. Chemicals called cryoprotectants are used during this process to prevent ice crystals forming, which could damage the embryos. Then the embryos are immediately exposed to liquid nitrogen to freeze them rapidly, ready for storage. When needed, this process is reversed to thaw and warm the embryos quickly. Vitrification is a simple, fast and inexpensive technique, which has become a fundamental tool in fertility treatments in recent years because of its higher embryo survival rates and better clinical outcomes.

Read more: https://academic.oup.com/DocumentLibrary/humrep/PR_Papers/deaa136.pdf

What are your chances of having a second IVF baby after fertility treatment for the first?

What are your chances of having a second IVF baby after fertility treatment for the first?

Women have a good chance of having a second child with the help of fertility treatment after the birth of their first child born this way, according to the first study to investigate this, published today in Human Reproduction, one of the world’s leading reproductive medicine journals.

Researchers in Australia calculated that after a woman successfully achieved a live birth using in vitro fertilisation (IVF), also known as assisted reproductive technology (ART), the chances of a second ART baby were between 51% and 88% after six cycles of treatment.

These calculations depended on whether or not previously frozen embryos were used or fresh embryos from a new ovarian stimulation cycle, and on assumptions made about the likely success rate for women who discontinued treatment.

The chances of a second ART baby decreased with increased maternal age.

Compared to women younger than 30 years, the likelihood of women aged 35-39 having a second ART-conceived baby reduced by 22% if they recommenced treatment with a frozen embryo from a previous cycle and by 50% if they recommenced treatment with a new cycle and a fresh embryo.

Factors that improved their chances of a successful second pregnancy included requiring only one cycle and a single embryo transfer to achieve a first live birth, and where infertility was caused by factors affecting the male partner.

Professor Georgina Chambers, director of the National Perinatal Epidemiology and Statistics Unit at the University of New South Wales (Sydney, Australia), looked at data from 35,290 women who received ART treatment between 2009 and 2013 in Australia and New Zealand and had a live baby during this time. These women were followed for a further two years to 2015, providing between two and seven years of follow-up data, and live births up to October 2016 were included.

We calculated two measures: what is a woman’s chance of achieving a second live birth in a particular cycle of treatment if previous cycles have failed, for instance in cycle three if the first two cycles have failed; and what is the overall, or cumulative, chance of a woman achieving a live birth after a particular number of cycles, including all the previous cycles. For example, what is the overall chance of a woman having a baby after up to three cycles,” said Prof Chambers.

A cycle includes the stimulation of the ovaries to mature multiple eggs, the collection of eggs for fertilisation in the laboratory to create embryos, and then all embryo transfer procedures that use the embryos from the egg retrieval procedure. This can include fresh embryo transfers and frozen embryo transfers.

Prof Chambers and her colleagues calculated estimates of cumulative live birth rates (CLBR) for women who were trying for a second ART baby that took account not only of the women who continued treatment, but also those who discontinued treatment.

The conservative CLBR assumed that women who dropped out would have no chance of achieving a second live birth if they had continued treatment. The optimal CLBR assumed these women would have the same chance of a live birth in a particular cycle as women who had continued treatment. The range between the conservative and optimal estimates gives a realistic idea of success rates.

Just over 43% (15,325) of the 35,290 women, with an average (median) age of 36, returned for treatment to conceive a second child by December 2015.

Among these women, 73% used a frozen embryo from the egg retrieval cycle that had resulted in their first child, and for them the CLBR ranged from 61% (conservative estimate) to 88% (optimal estimate) after six cycles. Among the women who had a new stimulation cycle and used a fresh embryo, the CLBR ranged from 51% to 70%.

Overall, 43% of women who recommence treatment with one of the frozen embryos from a previous stimulation cycle will have a baby after their first embryo transfer procedure. Between 61% and 88% of these women will have a baby after six cycles,” said Prof Chambers. “Among those who recommence treatment with a new stimulation cycle and a fresh embryo transfer, 31% will have a baby after their first cycle and between 51% and 70% after six cycles.”

Although success rates declined with female age, the researchers found that after three cycles of treatment, the conservative and optimal CLBRs in women aged 40 to 44 years were 38% and 55% respectively in those that started with a frozen embryo, and 20% and 25% in those recommencing with a new stimulated cycle and fresh embryos.

Read more: https://academic.oup.com/humrep/advance-article/doi/10.1093/humrep/deaa030/5817569

Hungary to provide free IVF to boost population

Hungary to provide free IVF to boost population

Hungary will provide free in-vitro fertilisation (IVF) treatment to couples at state-run clinics, Prime Minister Viktor Orban has announced.

He said fertility was of “strategic importance”. Last month his government took over Hungary’s fertility clinics.

Mr Orban, a right-wing nationalist, has long advocated a “procreation over immigration” approach to deal with demographic decline.

The country’s population has been falling steadily for four decades.

Mr Orban described details of his fertility policy on Thursday, after bringing six fertility clinics under state control in December.

Free IVF treatment will be offered from 1 February, but it is not clear who exactly will be entitled to it.

Mr Orban also said the government was considering an income tax exemption for women who have three children or more. Starting this month, those with at least four children have been exempt.

“If we want Hungarian children instead of immigrants, and if the Hungarian economy can generate the necessary funding, then the only solution is to spend as much of the funds as possible on supporting families and raising children,” the prime minister said.

Mr Orban – who has been prime minister since 2010 – has based his campaigns on opposition to immigration.

In September last year, he told an international summit on demography that while other European leaders believed immigration was the solution to falling population numbers, he rejected this.

The prime minister then echoed the far-right “great replacement” theory, which claims that white European populations are being gradually replaced by people of non-European descent.

“If Europe is not going to be populated by Europeans in the future, and we take this as given, then we are speaking about an exchange of populations, to replace the population of Europeans with others,” Mr Orban told the conference at the time.

“There are political forces in Europe who want a replacement of population for ideological or other reasons.”

With an estimated birth rate of 1.48 per woman, Hungary is just one of many Eastern European countries facing demographic decline – due to both low birth rates and the emigration of working-age people to other EU nations.

Some of these countries have implemented their own policies to encourage birth rates to increase. Poland, for example, pays parents 500 zloty (£100) a month per child.

Croatia, which assumed presidency of the EU last week, said last year that population growth in the EU would be “a ­key question” for them.

“Demography needs to be put in the focus of EU policies in order to preserve the development of all member states,” Croatian minister Vesna Bedekovic told a European Economic and Social Committee conference in November.

“The birth rate currently stands at 1.59 on average… This is why Croatia has recognised demographic revitalisation as a key question for its further development.”

Source: https://www.bbc.com/news/world-europe-51061499

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