Assisted conception, Australia and New Zealand 1997

Assisted conception, Australia and New Zealand 1997 is the fourth 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) and gamete intrafallopian transfer (GIFT) in 29 units in 1997. New Zealand had 6 IVF units in this period. There were 3,164 births after assisted conception in Australia in 1996, accounting for 1.2% of all births. In New Zealand, there were 254 births after assisted conception in 1996. The number of births continued to increase in 1997, by 9.3% to 3,458 in Australia and by 7.9% to 274 in New Zealand.
• There has been a marked increase in treatment cycles in which intracytoplasmic sperm injection (ICSI) was attempted. Oocyte retrieval cycles for microinsemination increased from 1,243 in 1993 to 2,786 in 1994, 4,261 in 1995, 5,271 in 1996 and 6,308 in 1997. With an additional 3,203 embryo transfer cycles in 1997 after microinsemination and embryo freezing, microinsemination accounted for 40.7% of all transfer cycles in that year. The overall proportion of assisted conception pregnancies resulting from ICSI and other types of microinsemination increased rapidly from less than 1 in 200 (0.4%) in 1990 to 1 in 3 (33.2%) in 1996 and more than 1 in 3 (37.9%) in 1997.
• When all techniques of assisted conception are included together, the viable pregnancy rate in 1997 was 15.2 per 100 embryo transfer cycles, indicating that more than 1 in 7 treatment cycles reaching the stage of embryo transfer resulted in a viable pregnancy of 20 weeks or more.
• In 1997, after transfer of fresh embryos to the uterus, the viable pregnancy rate was 13.3 per 100 oocyte retrieval cycles for IVF without ICSI and 14.7 per 100 oocyte retrieval cycles for ICSI. After GIFT, the viable pregnancy rate was 20.0 per 100 oocyte retrieval cycles.
• After embryo freezing in 1997, the viable pregnancy rate was 12.2 per 100 embryo transfer cycles for IVF without ICSI and 11.4 per 100 embryo transfer cycles for ICSI. After oocyte donation and IVF, the viable pregnancy rate was 15.3 per 100 embryo transfer cycles.
• Between 1996 and 1997, there were slight decreases in the proportion of cycles with more than 3 embryos or oocytes transferred. For all IVF, more than 3 embryos were transferred to the uterus in 2.8% of cycles in 1996 and 2.7% of cycles in 1997; for GIFT, more than 3 oocytes were transferred in 7.2% of cycles in 1996 and 6.9% of cycles in 1997. Women aged 40 years and over accounted for 17.1% of IVF oocyte retrieval cycles, 12.0% of ICSI retrieval cycles, 17.4% of GIFT retrieval cycles, 12.1% of IVF transfer cycles after embryo freezing, 9.1% of ICSI transfer cycles after embryo freezing, and 48.4% of transfer cycles after use of donor oocytes and embryo freezing.
• Among 4,476 IVF pregnancies after intracytoplasmic sperm injection and other methods of microinsemination between 1990 and 1997, live births occurred in 77.5%, spontaneous abortion in 19.1%, and ectopic pregnancy in 1.9%. Twins occurred in 17.6% of viable pregnancies, triplets in 1.3%, and there were five quadruplet pregnancies. Among 4,237 ICSI births, the perinatal death rate was 26.2 per 1,000 births; for singleton births, it was 15.8 per 1,000 births; for twins, 42.1 per 1,000 births; and for triplets, 85.1 per 1,000 births. Congenital malformations were reported in 118 (2.8%) fetuses and infants after ICSI, similar to the overall rate among IVF births (2.6%) and GIFT births (2.4%).