Assisted reproductive technology in Australia and New Zealand 2009
This is the fifteenth annual report on the use of assisted reproductive technologies (ARTs) in Australia and New Zealand. The report presents data on ART treatment and donor insemination cycles undertaken in 2009, and the resulting pregnancies and baby outcomes.
Use of ART treatment cycles
There were 70,541 ART treatment cycles reported in Australia and New Zealand in 2009, a 13.9% increase on 2008 and a 48.0% increase on 2005. Of these, 92.4% were in Australian fertility centres and 7.6% were in New Zealand fertility centres. Women used their own oocytes/embryos in more than 95%of treatments (autologous), and 33.8% of all cycles used frozen/thawed embryos. It is estimated that more than 35,000 women undertook autologous ART treatment in Australia and New Zealand in 2009. On average, 1.8 fresh and/or thaw cycles per woman were performed in 2009.
Treatment outcomes and number of babies
Of the 70,541 treatment cycles, 22.6% resulted in a clinical pregnancy, and 17.2% resulted in a live delivery (the birth of at least one liveborn baby). There were 12,127 live deliveries resulting in 13,114 liveborn babies including 9,732 singletons at term of normal birthweight.
Women’s age and parity
The average age of women undergoing autologous cycles was 35.8 years, about the same as the average age (35.7 years) in 2008. One in four (26.8%) autologous fresh cycles undertaken in 2009 was in women aged 40 years or older. The average age of women undergoing ART treatment using donor oocytes/embryos was 40.8 years. Almost one-quarter (24.5%) of cycles were undertaken by women who had previously given birth. Advancing women’s age is associated with the decrease in the live delivery rates. Of autologous fresh cycles, the live delivery rate per initiated cycle was 26.8% for cycles in women aged 30–34 years. It decreased to less than 1% for cycles in women aged over 44 years. Of autologous thaw cycles, the live delivery rate per initiated cycle fell from 20.1% of cycles in women aged 30–34 years to 2.4% of cycles in women aged over 44 years.
Transfer of cryopreserved embryos
Of the 22,472 frozen/thawed embryo transfer cycles, 18.3% involved the transfer of embryos that had been cryopreserved using an ultra-rapid method (vitrification). One-third of thaw cycles where a blastocyst (day 5–6 embryo) was transferred used vitrified blastocysts, compared to 1.7% of cycles where a cleavage embryo (day 2–3 embryo) was transferred.
A continuing trend in ART treatment has been the reduction in the rate of multiple birth deliveries from 14.1% in 2005 to 8.2% in 2009. This reduction was achieved by a shift in practice by clinicians and patients to single embryo transfer, with the proportion of single embryo transfer cycles increasing from 48.3% in 2005 to 69.7% in 2009. Importantly, this substantial decrease in the multiple delivery rate was achieved while clinical pregnancy rates remained stable at around 23% per cycle.
Authors: Yueping A. Wang, Alan Macaldowie, Irene Hayward, Georgina M. Chambers and Elizabeth A Sullivan.