Increased chances of successful IVF if 18 to 20 eggs are retrieved

September 4, 2018, University of Gothenburg
Increased chances of successful IVF if 18 to 20 eggs are retrieved
Newborn baby. Credit: iStock

The likelihood of childbirth after in vitro fertilization (IVF) treatment increases if 18 to 20 eggs are stimulated to mature in a woman's ovaries, a dissertation at Sahlgrenska Academy, Sweden, shows. That is more eggs than the number aimed at in today's IVF treatments.

"The results can serve as the basis for how hormone stimulation before IVF treatment is designed in the future with the intention of achieving a good balance between effective and medically safe treatment," says Åsa Magnusson, MD/PgD at Sahlgrenska University Hospital and Sahlgrenska Academy.

To an increasing extent both in Sweden and internationally, only one fertilized egg, or embryo, is retrieved per treatment occasion. If the treatment results in more high-quality , these can be frozen and used in later attempts.

Previous research on the total number of eggs that should be retrieved have indicated that the chance of birth after IVF is optimal after about 10 eggs. It has been believed that a greater number of eggs leads not to a better chance of birth but rather to an increased risk of serious side effects.

No demonstrated risk for children

However, the studies carried out have mainly examined the delivery rate after the first implantation, called the fresh IVF cycle, which takes place just days after the egg retrieval. Later implants of thawed embryos have not been included.

"It's more relevant to study the cumulative chance of children per IVF attempt when all embryo transfers that are generated from an egg retrieval are included," Åsa Magnusson says. "However, it's also important to study the risks in relation to the number of retrieved eggs and serious side effects, both during the stimulation and also neonatal pregnancy and childbirth complications."

The study does not show any connection between egg retrieval and complications for the children. On the other hand, there is a weak but statistically valid correlation between the number of retrieved eggs and placenta previa, a condition that can cause bleeding during pregnancy or childbirth.

Optimal chances – a reasonable risk level

The transfer of thawed embryos accounts for about one-third of all IVF cycles in Sweden, and the chance of birth is now comparable with the transfer of fresh embryos. It can thus be beneficial to design hormone stimulation before egg retrieval so that extra embryos can be produced and frozen to avoid additional hormone treatment.

To study the relationship between the number of collected eggs, cumulative delivery rate and serious complications associated with the stimulation, such as ovarian hyperstimulation syndrome and blood clots, treatment data from the Swedish National Quality Registry of Assisted Reproduction (Q-IVF) has been matched with data from the Swedish Patient Register and the Swedish Medical Birth Register for the 2002–2015 period.

"Previously about 10 eggs has been considered optimal for the chance of childbirth after the fresh cycle. We observed that the cumulative chance rose with an increased number of eggs, up to 18–20, and then leveled off. At the same time, the risk of complications remained at a reasonable level up to 18–20 eggs. At a higher number of , the risks increased," Åsa Magnusson says.

Explore further: The more eggs the better in IVF?

More information: Ovarian stimulation for IVF-a balance between efficacy and safety. gupea.ub.gu.se/handle/2077/55398

Related Stories

The more eggs the better in IVF?

July 3, 2017
A higher number of eggs retrieved in an IVF treatment cycle is independently associated with more chromosomally normal embryos available for transfer, according to a new Australian study. However, the benefit of a greater ...

For women undergoing IVF, is fresh or frozen embryo transfer best?

August 21, 2018
The world's first baby born via in-vitro fertilization turned 40 years old this summer. Still, after four decades, IVF is a relatively new field with ongoing debate on how to get the best results for families who have placed ...

National study identifies best method for achieving a healthy IVF birth

November 1, 2017
Research presented today at the American Society for Reproductive Medicine (ASRM) by scientists from the University of Colorado and Duke University concludes that fresh donor eggs during in vitro fertilization (IVF) provide ...

15 eggs is the perfect number needed to achieve a live birth after IVF

May 11, 2011
An analysis of over 400,000 IVF cycles in the UK has shown that doctors should aim to retrieve around 15 eggs from a woman's ovaries in a single cycle in order to have the best chance of achieving a live birth after assisted ...

IVF in women over 38: The doctor's dilemma

June 16, 2015
It is a biological fact that female fertility declines with age - in assisted conception as in natural. Indeed, findings from a 12-year study reported today at the Annual Meeting of ESHRE by Dr Marta Devesa from the Hospital ...

Women now have clearer statistics on whether IVF is likely to work

July 24, 2017
Australian women considering IVF will now, for the first time, have a more meaningful idea of their chances of having a baby, whether it's their first or subsequent round of IVF.

Recommended for you

Undiagnosed STIs can increase negative PMS symptoms

September 17, 2018
Women that have undiagnosed sexually transmitted infections may be at greater risk of experiencing negative premenstrual symptoms (PMS), according to new Oxford University research.

High dose folic acid does not prevent pre-eclampsia in high risk women

September 13, 2018
Taking high dose folic acid supplements in later pregnancy (beyond the first trimester) does not prevent pre-eclampsia in women at high risk for this condition, finds a randomised controlled trial published by The BMJ today.

Study finds air purifiers may benefit fetal growth

September 12, 2018
A new study led by SFU health sciences researchers Prabjit Barn and Ryan Allen reveals fetal growth may improve if pregnant women use portable air purifiers inside their homes.

Delayed childbearing is a growing source of multiple births, study shows

September 12, 2018
Starting in the 1980s, the number of multiple births—twins, triplets, quadruplets and quintuplets—steadily increased from about 20 sets per 1,000 live births to almost 35 sets per 1,000 live births in the 2010s.

Transforming pregnancy research with a smartphone app

September 5, 2018
For years, pregnant women have been underrepresented in biomedical research. Current treatments, interventions and guidelines do a poor job of taking into consideration the diverse characteristics of all pregnant women.

Study finds women with pregnancy-related nausea, vomiting use marijuana more

August 20, 2018
A Kaiser Permanente study, published today in JAMA Internal Medicine, found that women with mild and severe nausea and vomiting in pregnancy were significantly more likely to have used marijuana during pregnancy than women ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.