Assisted reproductive technology in Australia and New Zealand 2017

Summary

Assisted reproductive technology (ART) is a group of procedures that involve the in vitro (outside of body) handling of human oocytes (eggs) and sperm or embryos for the purposes of establishing a pregnancy. Each ART treatment involves a number of stages and is generally referred to as an ART treatment cycle. The embryos transferred to a woman can either originate from the cycle in which they were created (fresh cycle) or be frozen (cryopreserved) and thawed before transfer (thaw cycle). There were 82,215 ART treatment cycles reported from Australian and New Zealand fertility clinics in 2017 (74,942 and 7,273 respectively), representing an increase of 0.8% in Australia and 8.5% in New Zealand from 2016. This equates to 14.8 cycles per 1,000 women of reproductive age (15–44 years) in Australia, compared with 7.6 cycles per 1,000 women of reproductive age in New Zealand. Women used their own oocytes or embryos (autologous cycles) in 94.1% of treatments. Embryos and oocytes that had been frozen and thawed were used in 38.5% of autologous cycles. There were 40,375 women who undertook 77,353 autologous fresh and/or thaw cycles in Australia and New Zealand in 2017. On average, 1.9 autologous fresh and/or thaw cycles per woman were undertaken in 2017, with more cycles per woman in Australia (1.9 cycles per woman) than in New Zealand (1.7 cycles per woman). The number of cycles where embryos were selected using preimplantation genetic testing (PGT) increased by 23.5% from 7,425 in 2016 to 9,169 in 2017. Over the last five years the proportion of cycles where all oocytes or embryos were cryopreserved for potential future use (freeze-all cycles) has more than doubled from 10.5% of initiated fresh cycles in 2013 to 24.2% in 2017. This practice is used for a variety of reasons, including reducing the risk of ovarian hyperstimulation syndrome (OHSS), improving endometrial - embryo synchronicity, as part of a PGT cycle or for fertility preservation.

Patient's age

The average age of women undergoing autologous cycles in 2017 was 35.7 years, which is similar to previous years. The average age of women undergoing ART treatment using donor oocytes or embryos was approximately five years older at 40.3 years. Approximately one in four (23.4%) women who underwent an autologous cycle in 2017 were aged 40 years or older. The average age of male partners of women undergoing autologous and recipient cycles was 38.1 years, with approximately one-third (32.3%) aged 40 years or older. Of the 82,215 initiated ART cycles, 67,704 (82.4%) resulted in either an embryo transfer or all oocytes/embryos being cryopreserved. Of the initiated cycles, 22.9% (18,860) resulted in a clinical pregnancy and 18.1% (14,882) in a live delivery. The overall clinical pregnancy rate for cycles reaching embryo transfer was 33.9%. The live delivery rate per initiated autologous fresh cycle was 16.4% after freeze-all cycles were excluded, and 24.1% for fresh cycles reaching embryo transfer. The live delivery rate per initiated autologous thaw cycle was 27.9% and for thaw cycles reaching embryo transfer cycle was 28.9%.

Treatment  outcomes and number of babies

Of the 82,215 initiated ART cycles, 67,704 (82.4%) resulted in either an embryo transfer or all oocytes/embryos being cryopreserved. Of the initiated cycles, 22.9% (18,860) resulted in a clinical pregnancy and 18.1% (14,882) in a live delivery. The overall clinical pregnancy rate for cycles reaching embryo transfer was 33.9%. The live delivery rate per initiated autologous fresh cycle was 16.4% after freeze-all cycles were excluded, and 24.1% for fresh cycles reaching embryo transfer. The live delivery rate per initiated autologous thaw cycle was 27.9% and for thaw cycles reaching embryo transfer cycle was 28.9%. vii There was a higher live delivery rate in younger women. For women aged younger than 30 years, the live delivery rate per embryo transfer was 38.5% for autologous fresh cycles and 33.1% for autologous thaw cycles. For women older than 44 years, the live delivery rate per embryo transfer was 1.4% for autologous fresh cycles and 10.6% for thaw cycles. There were 15,613 babies born (including 15,405 liveborn babies) following ART treatment in 2017. Of these, 13,944 (89.3%) were from Australian clinics and 1,669 (10.7%) from New Zealand clinics. Eight in ten liveborn babies (80.2%) were full-term singletons of normal birthweight.

Cycle-specific success roles

ANZARD includes data items that make it possible to follow a woman’s consecutive ART treatment cycles. A cohort of 15,530 women were followed from the start of their first autologous non-freeze-all fresh cycle during 2015, through subsequent fresh and thaw cycles until December 2017 or until they achieved a live delivery. The cycle-specific live delivery rate per initiated cycle for all women was 22.9% in their first cycle, and 17.2% after eight cycles. Approximately one-third of women who did not achieve a live birth in a specific cycle discontinued ART treatment during the period.

Trends in ART procedures

Treatment trends in the last five years have included a continued shift from cleavage stage transfers to blastocyst transfers (from 61.1% in 2013 to 82.0% in 2017); an increase in vitrification as a cryopreservation method (from 82.9% of thaw blastocyst transfer cycles in 2013 to 91.5% in 2017); and a small decrease in the use of intracytoplasmic sperm injection (ICSI) (from 63.9% of embryo transfer cycles in 2013 to 62.2% in 2017). The proportion of embryo transfer cycles transferring a cryopreserved embryo increased from 44.7% in 2013 to 55.8% in 2017. Of the 14,882 live deliveries resulting from ART treatment in 2017, 60.2% resulted from thaw cycles, compared to 44.4% in 2013. In the last five years the live delivery rate per fresh embryo transfer cycle increased from 23.7% to 24.1%, and the live delivery rate per thaw embryo transfer cycle increased from 23.4% to 28.9%. This could be explained by the increase in freeze-all cycles over the years. Overall, live delivery rates per embryo transfer have risen from 23.6% in 2013 to 26.8% in 2017, a 13.6% improvement.

Multiple birth trends

A continuing trend in ART treatment in Australia and New Zealand has been the reduction in the rate of multiple deliveries, from 5.6% in 2013 to 3.6% in 2017. This has been achieved by clinicians and patients shifting to single embryo transfer, with the proportion increasing from 76.3% in 2013 to 89.4% in 2017. Importantly, this decrease in the multiple delivery rate has been achieved while overall live delivery rates per embryo transfer increased from 23.6% in 2013 to 26.8% in 2017.