Trends in Success Rates

The following graphs are from a summary report Assisted Reproductive Technology in Australia and New Zealand 2016, published September 2018 and available at https://npesu.unsw.edu.au/surveillance-reports.
Thaw cycles refer to embryo transfer using embryos which have been frozen and then thawed, or what we call a frozen embryo treatment cycle (FET). See section Success Rates>IVF Success Rates for fresh cycle data.
The report uses the term ‘autologous’ which simply means that the embryos result from the use of the patient’s own eggs/oocytes. Therefore it does not include donor oocyte cycles. However, an autologous cycle can include either the male partner’s sperm or donor sperm.

The above graph shows that the donor oocyte cycles in Australia and New Zealand in 2016 were relatively insignificant compared to autologous (own oocyte) cycles.

 

NOTE:

• Live deliveries per initiated ART cycle includes IVF and FET cycles (light blue dotted line)
• Live deliveries per initiated fresh cycle is IVF cycles (dark blue line)
• Live deliveries per initiated thaw cycle is FET cycles (green line)
• Multiple birth rate is mainly twins but may include triplets and quadruplets (very rare) (yellow dot/dash line)

It is not surprising that the multiple birth rate has steadily declined since 2012 as doctors try to avoid multiple births (usually twins) in order to reduce complications for both the mother and babies.  In order to reduce the likelihood of multiple pregnancy, the number of embryos transferred is limited.  This affects the IVF pregnancy rate and we see that the IVF success rate has marginally declined.  A growing number of freeze-all cycles also contributes to the reduction in IVF success rates.

In contrast to the slight decline in the IVF rate, the FET success rate has grown, probably due to enhanced technical proficiency.