Assisted reproductive technology in Australia and New Zealand 2018

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 84,064 ART treatment cycles reported from Australian and New Zealand fertility clinics in 2018 (76,341 and 7,723 respectively), representing an increase of 1.9% in Australia and 6.2% in New Zealand from 2017. This equates to 14.8 cycles per 1,000 women of reproductive age (15–44 years) in Australia, compared with 7.9 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 36.9% of autologous cycles. 

There were 41,927 women who undertook 79,072 autologous fresh and/or thaw cycles in Australia and New Zealand in 2018. On average, 1.9 autologous fresh and/or thaw cycles per woman were undertaken in 2018, 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) marginally decreased from 9,169 in 2017 to 9,124 in 2018.  

Over the last five years the proportion of cycles where all oocytes or embryos were cryopreserved for potential future use (freeze-all cycles) has doubled from 13% of initiated fresh cycles in 2014 to 26.7% in 2018. 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 2018 was 35.8 years, which is similar to previous years. The average age of women undergoing ART treatment using donor oocytes or embryos was around five years older at 40.3 years. Approximately one in four (23.7%) women who underwent an autologous cycle in 2018 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 (31.5%) aged 40 years or older. 

Treatment outcomes and number of babies

Of the 84,064 initiated ART cycles, 70,196 (83.5%) resulted in either an embryo transfer or all oocytes/embryos being cryopreserved. Of the initiated cycles, 23.2% (19,514) resulted in a clinical pregnancy and 18.4% (15,475) in a live birth. The overall clinical pregnancy rate for cycles reaching embryo transfer was 34.4%. In 2018, there were 4 GIFT cycles resulting in 2 live births. The live birth rate per initiated autologous fresh cycle was 16.8% after freeze-all cycles were excluded, and 24.5% for fresh cycles reaching embryo transfer. The live birth rate per initiated autologous thaw cycle was 28.5% and for thaw cycles reaching embryo transfer cycle was 29.4%. There was a higher live birth rate in younger women. For women aged younger than 30 years, the live birth rate per embryo transfer was 40.4% for autologous fresh cycles and 34.9% for autologous thaw cycles. For women older than 44 years, the live birth rate per embryo transfer was 0.8% for autologous fresh cycles and 7.8% for thaw cycles. 
There were 16,140 babies born (including 15,980 liveborn babies) following ART treatment in 2018. Of these, 14,355 (88.9%) were from Australian clinics and 1,785 (11.1%) from New Zealand clinics. Eight in ten liveborn babies (81.5%) 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 15,404 women were followed from the start of their first autologous non-freeze-all fresh cycle during 2016, through subsequent fresh and thaw cycles until December 2018 or until they achieved a live birth. The cycle-specific live birth rate per initiated cycle for all women was 23.1% in their first cycle, and 11.6% in their eighth cycle. Approximately one in four 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 67.5% in 2014 to 86.6% in 2018); an increase in vitrification as a cryopreservation method (from 85.6% of thaw blastocyst transfer cycles in 2014 to 94.1% in 2018); and a small decrease in the use of intracytoplasmic sperm injection (ICSI) (from 63.8% of embryo transfer cycles in 2014 to 60.3% in 2018). 
The proportion of embryo transfer cycles transferring a cryopreserved embryo increased from 47.1% in 2014 to 57.2% in 2018. Of the 15,475 live births resulting from ART treatment in 2018, 61.5% resulted from thaw cycles, compared to 48.4% in 2014. 
In the last five years the live birth rate per fresh embryo transfer cycle increased from 23.7% to 24.6%, and the live birth rate per thaw embryo transfer cycle increased from 24.9% to 29.3%. This could be explained by the increase in freeze-all cycles over the years. Overall, live birth rates per embryo transfer have risen from 24.3% in 2014 to 27.3% in 2018, a 12.3% improvement. 

Multiple birth trends

A continuing trend in ART treatment in Australia and New Zealand has been the reduction in the rate of multiple births, from 4.9% in 2014 to 3.2% in 2018. This has been achieved by clinicians and patients shifting to single embryo transfer, with the proportion increasing from 79.2% in 2014 to 90.6% in 2018. Importantly, this decrease in the multiple birth rate has been achieved while overall live birth rates per embryo transfer increased from 24.3% in 2014 to 27.3% in 2018.