Pregnancy rate is the success rate for pregnancy. For IVF, it is the percentage of all attempts that lead to pregnancy, which generally refers to treatment cycles where eggs are retrieved and fertilised in vitro. Statistics referring to "pregnancy" may refer to just a positive pregnancy test, and not necessarily "viable pregnancy" which implies the detection of a fetal heart beat. Pregnancies that are delivered with a viable baby are called live birth rate. Increasingly a distinction is also made between singleton and multiple pregnancies as multiple pregnancies, specifically more than twins, should be avoided because of the associated maternal and fetal risks.
With enhanced technology, the pregnancy rates are substantially better today than a couple of years ago. In 2006, Canadian clinics reported an average pregnancy rate of 35%. A French study estimated that 66% of patients starting IVF treatment finally succeed in having a child (40% during the IVF treatment at the center and 26% after IVF discontinuation). Achievement of having a child after IVF discontinuation was mainly due to adoption (46%) or spontaneous pregnancy (42%).
Live birth rateLive birth rate is the percentage of all IVF cycles that lead to live birth, and is the pregnancy rate adjusted for miscarriage and stillbirth. These percentages are for successful pregnancies, regardless of the number of children born, as twins and larger multiple-order births are more common in IVF cycles. The results in labs across the United States show that conception using IVF with a male who has a low sperm count produces a higher chance of a live birth than a female with a low egg count.
In 2006, Canadian clinics reported a live birth rate of 27%. Birth rates in younger patients were slightly higher, with a success rate of 35.3% for those 21 and younger, the youngest group evaluated. Success rates for older patients were also lower and decrease with age, with 37-year-olds at 27.4% and no live births for those older than 48, the oldest group evaluated.Some clinics exceeded these rates, but it is impossible to determine if that is due to superior technique or patient selection, because it is possible to artificially increase success rates by refusing to accept the most difficult patients or by steering them into oocyte donation cycles (which are compiled separately). Further, pregnancy rates can be increased by the placement of several embryos at the risk of increasing the chance for multiples.
Because not each IVF cycle that is started will lead to oocyte retrieval or embryo transfer, reports of live birth rates need to specify the denominator, namely IVF cycles started, IVF retrievals, or embryo transfers. The Society for Assisted Reproductive Technology (SART) summarised 2008-9 success rates for US clinics for fresh embryo cycles that did not involve donor eggs and gave live birth rates by the age of the prospective mother, with a peak at 41.3% per cycle started and 47.3% per embryo transfer for patients under 35 years of age.
IVF attempts in multiple cycles result in increased cumulative live birth rates. Depending on the demographic group, one study reported 45% to 53% for three attempts, and 51% to 71% to 80% for six attempts.
With enhanced technology, the pregnancy rates are substantially better today than a couple of years ago. In 2006, Canadian clinics reported an average pregnancy rate of 35%. A French study estimated that 66% of patients starting IVF treatment finally succeed in having a child (40% during the IVF treatment at the center and 26% after IVF discontinuation). Achievement of having a child after IVF discontinuation was mainly due to adoption (46%) or spontaneous pregnancy (42%).
Live birth rateLive birth rate is the percentage of all IVF cycles that lead to live birth, and is the pregnancy rate adjusted for miscarriage and stillbirth. These percentages are for successful pregnancies, regardless of the number of children born, as twins and larger multiple-order births are more common in IVF cycles. The results in labs across the United States show that conception using IVF with a male who has a low sperm count produces a higher chance of a live birth than a female with a low egg count.
In 2006, Canadian clinics reported a live birth rate of 27%. Birth rates in younger patients were slightly higher, with a success rate of 35.3% for those 21 and younger, the youngest group evaluated. Success rates for older patients were also lower and decrease with age, with 37-year-olds at 27.4% and no live births for those older than 48, the oldest group evaluated.Some clinics exceeded these rates, but it is impossible to determine if that is due to superior technique or patient selection, because it is possible to artificially increase success rates by refusing to accept the most difficult patients or by steering them into oocyte donation cycles (which are compiled separately). Further, pregnancy rates can be increased by the placement of several embryos at the risk of increasing the chance for multiples.
Because not each IVF cycle that is started will lead to oocyte retrieval or embryo transfer, reports of live birth rates need to specify the denominator, namely IVF cycles started, IVF retrievals, or embryo transfers. The Society for Assisted Reproductive Technology (SART) summarised 2008-9 success rates for US clinics for fresh embryo cycles that did not involve donor eggs and gave live birth rates by the age of the prospective mother, with a peak at 41.3% per cycle started and 47.3% per embryo transfer for patients under 35 years of age.
IVF attempts in multiple cycles result in increased cumulative live birth rates. Depending on the demographic group, one study reported 45% to 53% for three attempts, and 51% to 71% to 80% for six attempts.
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