Donor Egg Success Rates
The success rates for fertility treatment using IVF technology is one area that abounds in over exaggeration and misunderstanding.
Part of the problem is that 2 different rates can be quoted (basically)
- Pregnancy rate
This is defined as the presence of a foetus with foetal heart usually diagnosed on transvaginal ultrasound early in the fist trimester ± 6-7 weeks.
- Live birth rate
This accurately describes the live birth rate.
These rates can be further complicated depending upon the number of embryos transferred, as well as other parameters
In view of the fact that our patients have been expertly evaluated prior to embarking on oocyte donation, the major factors affecting outcome are predominantly:
- Age of the egg donor
- Sperm quality
- Number of embryos transferred
Our current average pregnancy rate for the last 10 years is 74% and live birth 65%.
These results are essentially similar to IVF success rates in Australia and Overseas, taking into account the donor’s age, ( 24-32 years) with the majority being under 30 years, coupled with multiple embryo transfer again the majority of patients electing for 2 embryos to be transferred.
How Many Embryos should be Transferred?
Under ideal circumstances the preferred option is ONE embryo!
If you decide to transfer more than one embryo you run the risk of multiple pregnancy, so that when 2 embryos are transferred the risk of a multiple pregnancy is 20% (twins) and with 3 embryos the risk of multiple pregnancy is 25%, but in this case the risk is of triplets whose overall risk of complications compared to twins is ± 5-7x greater.
|Risk of twins compared with singleton pregnancy|
|Fetal growth restriction||x3|
|% of Preterm Deliveries vs Number of Foetuses|
|Number of fetuses||< 28 weeks||< 37 weeks|
Our patients are counselled about the risks of multiple, pregnancy especially the need to minimise prematurity.
Cross-border Reproductive Care (CBRC)
Unfortunately owing to the fact that patients seeking treatment with donor oocytes are often older, have to travel overseas and for many reasons are trying to maximise outcomes, achieving the highest pregnancy rate in the shortest possible time becomes their overriding aim. These patients often seek to have twins despite our advice to attempt a singleton pregnancy. Therefore they will elect to transfer more than one embryo. In fact for the last 10 years only 2 couples have elected to have single embryo transfers and this was related to attempts to have a second child with donor oocytes/embryos and fortunately both were successful.
Preterm Birth or Prematurity
Preterm birth (PTB), is birth at <37 completed weeks of gestation, and is a major health problem. The data from 2008 shows that PTB occurs in approximately 13% of all pregnancies.
In 1/3 of these preterm births, induced delivery was necessary to treat maternal of fetal disease.
The other 2/3 are the result of multiple factors of which an important contributor is multiple pregnancy possibly due to over distension of the uterus.
Preterm neonates are at greater risk for morbidity and mortality than infants born at term. A variety of health and developmental complications may arise, including acute respiratory distress syndrome, central nervous system deficits, vision impairments, gastrointestinal problems, and long-term motor and cognitive disabilities. PTB has considerable emotional and economic impacts on families and causes a significant burden to the healthcare system.
*However when reviewing these complications one has to look at the actual rate of a condition and then by how much it is increased. Take the risk of cerebral palsy for example in a singleton pregnancy is 0.19%. The risk in twins is 2x higher which means the actual risk is 0.38% or 3.8 cases per thousand. Thus the actual risk of many of these complications is actually quite low but unfortunately serious.
Donor ooctyes Australia strongly advises all patients to pay particular attention to this advice and recommends that they discuss it with Dr Joel Bernstein.
*Multiplicity and early gestational age contribute to an increased risk of cerebral palsy from assisted conception: a population-based cohort study.
D. Hvidtjørn1,*, J. Grove1, D. Schendel2, C. Sværke1, L.A. Schieve2, P. Uldall3,4, E. Ernst5, B. Jacobsson6, and P. Thorsen1
Human Reproduction, Vol.25, No.8 pp. 2115–2123, 2010