Assisted conception, Australia and New Zealand 1998 and 1999

Assisted conception, Australia and New Zealand 1998 and 1999 is the fifth report on the use of assisted reproduction technology (ART) in Australia and New Zealand.

Highlights

• In Australia, infertile couples were treated by in-vitro fertilisation (IVF), intracytoplasmic sperm injection (ICSI) and gamete intrafallopian transfer (GIFT) in 31 IVF units in 1999. New Zealand had 7 IVF units in this period. There were 3,873 births after assisted conception in Australia in 1998, accounting for 1.5% of all births. In New Zealand, there were 309 births after assisted conception in 1998.
• Between 1992 and 1999, the total number of cycles with oocyte retrieval or embryo transfer for all techniques of assisted conception increased by 63% from 16,288 in 1992 to 26,579 in 1999. There was a relatively greater increase in transfer cycles using frozen embryos than for fresh embryos.
• When all techniques of assisted conception are included together, the viable pregnancy rate increased from 13.0 per 100 embryo transfer cycles in 1992 to 15.9 in 1999.
• For IVF with transfer of fresh embryos, the viable pregnancy rate almost doubled from 8.6 per 100 oocyte retrieval cycles in 1992 to 15.4 in 1999. For IVF with transfer of frozen embryos, the viable pregnancy rate varied between 9.6 per 100 embryo transfer cycles in 1993 and 12.5 in 1996.
• There has been a marked increase in treatment cycles in which intracytoplasmic sperm injection (ICSI) was used for fertilisation. Oocyte retrieval cycles for microinsemination increased each year from 812 in 1992 to 8,022 in 1999. For ICSI with transfer of fresh embryos, the viable pregnancy rate increased from 6.8 per 100 oocyte retrieval cycles in 1992 to 16.3 in 1999. For ICSI with transfer of frozen embryos, the viable pregnancy rate fluctuated between 11.1 per 100 embryo transfer cycles in 1996 and 13.3 in 1994. Microinsemination accounted for 47.1% of transfer cycles for all types of assisted conception in 1999. The overall proportion of assisted conception pregnancies resulting from ICSI and other types of microinsemination increased rapidly from 18.3% (584/3,195) in 1994 to 46.0% (2,309/5,020) in 1999.
• The use of gamete intrafallopian transfer (GIFT) for treating infertility declined sharply during the 1990s, from 3,831 oocyte retrieval cycles in 1992 to 1,265 cycles in 1999, accounting for only 5.1% (1,239/24,521) of all transfer cycles in that year. The viable pregnancy rate varied between 18.2 per 100 oocyte retrieval cycles in 1999 and 22.0 in 1996.
• Between 1997 and 1999, the proportion of IVF and ICSI cycles in which one or two fresh embryos were transferred increased, from 64.9% to 76.4% for IVF and from 66.9% to 74.0% for ICSI. For thawed embryos, the proportion increased from 79.3% to 86.6% for IVF in the same period, and from 82.5% to 86.1% for ICSI. For GIFT, one or two oocytes were transferred in 51.6% of cycles in 1997, decreasing to 47.8% in 1999. Four or more oocytes were transferred in 10.8% of GIFT cycles in 1999.
• Information about artificial insemination performed at IVF units is included in this report for the first time. In 1998 and 1999, there were approximately 12,500 cycles of treatment by artificial insemination of husband's sperm or donor sperm reported by IVF clinics for each year. The viable pregnancy rate for artificial insemination in 1999 was 9.6 per 100 insemination cycles.
• In 1998, multiple pregnancy occurred in 27.8% of GIFT pregnancies, compared with 19.8% for IVF pregnancies and 19.0% for ICSI pregnancies. There were 3 quadruplet pregnancies and 44 sets of triplets among all assisted conception pregnancies in 1998.
• In the three-year period 1996-1998, multiple pregnancy for all types of assisted conception occurred in 20.2% of viable pregnancies and varied considerably among the IVF units. When IVF units were ranked into four groups, the multiple pregnancy rate among units in the highest group (26.1%) was almost twice that of units in the lowest group (13.4%).
• In 1998, 61% (61/100) of perinatal deaths after assisted conception occurred in multiple births. The perinatal death rate for all assisted conception births in 1998 was 23.9 per 1,000 births, similar to that in 1997 but lower than in earlier years. Perinatal death was more likely for multiple births than for singletons, increasing from 14.2 per 1,000 births for singletons, to 31.8 for twins, 113.6 for triplets, and 416.7 for quadruplets.