Pregnancy Rates
Everyone wants to know their chance of pregnancy, but the best we can do is give pregnancy rates for groups of people with similar circumstances.
The most important factors affecting pregnancy rate are:
- Age of the woman
- The number of embryos transferred in the case of IVF
There are various ways to present pregnancy rates:
- The chance of a birth from a single completed treatment. We consider a completed treatment as an IVF cycle with egg collection, or a donor cycle with insemination.
- Some cycles are stopped before IVF egg collection or donor insemination, but when this happens most of the non-drug costs are reimbursed.
- The chance of a clinical pregnancy from a single treatment. A clinical pregnancy is the presence of a fetal sac on ultrasound early in pregnancy, so excludes most miscarriages. Clinical pregnancy rates are used for recent data, since it takes at least 9 months to collect birth outcomes.
- Cumulative pregnancy rates, which is the overall chance of a birth. For instance, from the use of all the fresh and frozen embryos from an IVF cycle, or from several cycles of treatment.
- It can be useful to compare pregnancy rates with treatment with those of fertile people. As a yardstick, we use a birth rate of 20% per month for fertile women 37 and younger.
Important factors when comparing pregnancy rates:
- Am I comparing like with like - women’s age, number of embryos, clinical pregnancies or deliveries of a child, definition of a completed IVF cycle?
- Has a large number of treatment cycles been used to derive the statistics? Small numbers can give higher results in some groups just by chance. At Fertility Associates we like to start with at least 500-1000 cycles of treatment.
- What is the rate of twins and triplets? Many clinics increase their IVF pregnancy rate by transferring more than two embryos.
- What proportion of people were stopped before IVF egg collection? Fertility Associates patient information booklets give this information.
The following tables and graphs come from the most recent Fertility Associates patient information:
Cumulative birth rate per egg collection by woman's age
Cumulative birth rate from fresh embryo transfer plus any births from subsequent use of frozen embryos in the next six months if the woman did not become pregnant from the initial fresh embryo transfer. Data from all Fertility Associates clinics, 2003-2005.
Pregnancy rates per donor insemination cycle by age
- Statistics for DI (based on over 1000 treatments in 2003-2005)
| Woman's Age |
Positive pregnancy test |
Pregnancy visible on ultrasound |
Birth |
| 34 or younger |
26% |
25% |
22% |
| 35 - 37 |
22% |
19% |
14% |
| 38 - 39 |
17% |
14% |
10% |
| 40 - 41 |
12% |
11% |
7% |
| 42 or older |
8% |
6% |
4% |
Cumulative pregnancy rate for women 37 and younger after IVF/ICSI
This cumulative pregnancy graph shows the overall chance of having at least one child after one or two IVF/ICSI cycles, including the use of any "spare" frozen embryos. The graph is based on women starting IVF or ICSI in 2002 and 2003, with follow-up to the end of 2004.
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Cumulative pregnancy rate for women 37 and younger after DI
This cumulative pregnancy graph shows the overall chance of having a child after one or more treatments. The graph below shows the cumulative birth rate for women 37 or younger having DI who have not had a DI child before. As a comparison, the graph also shows the cumulative birth rate for fertile women, based on a 20% birth rate per month.
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