Maternal Age, Less than 30 years: over 60%
30 – 35 years: 45 – 50 %
35 – 40 years: Around 35 %
More than 40 years: Around 25 %
Maternal Age, Less than 30 years: over 60%
30 – 35 years: 45 – 50 %
35 – 40 years: Around 35 %
More than 40 years: Around 25 %
Maternal Age, Less than 30 years: Around 20 %
30 – 35 years: 15 – 20 %
35 – 40 years: Around 10 %
More than 40 years: Less than 10 %
For couples who have no difficulty achieving a pregnancy, the natural chance of pregnancy per month of ovulation is largely dependent on the age of the woman. For women in their early 30s or younger, the natural pregnancy rate is about 20 to 25 percent per cycle. This drops off significantly through her mid- and late-30s; by her early 40s, the chance of pregnancy is about 5 percent per cycle. This age-related decrease is primarily due to a decline in the quality of the eggs within the ovaries.
There is no agreed format for reporting ‘success rates’ when it comes to IVF and therefore the data can be presented differently, resulting in varying outcomes.
Complete IVF treatment cycle vs. embryo transfer :: IVF success rates can sometimes be reported per complete IVF treatment cycle. As explained above, a complete IVF treatment cycle can involve multiple transfers of embryos collected from the one egg collection. Success rates measured this way will therefore naturally be higher than success rates measured per embryo transfer.
Clinical pregnancy vs. live birth :: Clinical pregnancy rates (defined as a pregnancy confirmed by a blood test and ultrasound scan, usually at around 6-8 weeks) per embryo transfer is most often what is reported. Not all clinical pregnancies however will lead to a live delivery.
Each of the measures above measure the success rate once you reach the stage of an embryo transfer. Unfortunately, in some cases no embryos develop after the egg collection and therefore there is no embryo transfer. On some occasions, your fertility specialist may advise you to postpone the embryo transfer to carry out pre-implantation genetic screening on your embryos or to prevent ovarian hyperstimulation.
It is therefore important to understand what part of the IVF treatment cycle a particular statistic is measuring. There are also other factors that you need to consider and understand before you attempt to compare IVF success rates. These factors include:
A woman’s age is the most important factor affecting the chance of pregnancy success. Female fertility starts to decline when a woman is in her 30s onwards and declines rapidly once the woman is over 40. When looking at success rates ensure these have been broken into age bands. The IVF success rate of a 40 year old cannot be compared with that of a 30 year old.
Embryos that have grown to the blastocyst stage of development (day 5) have a greater potential to implant. However, not all embryos will progress from cleavage stage (day 2) to blastocyst stage. A poorer prognosis patient is likely to have lower egg numbers and will most likely have a cleavage stage transfer. It is important that you are comparing ‘like’ with ‘like’.
The doctor will explain your chances of success, taking into consideration your type of infertility, your age and type of treatment. Assisted Reproductive Technologies (ART) procedures have progressed rapidly since their development and so have the associated success rates. Advancements in technology at JFC allow us to routinely grow embryos to Blastocysts and use Vitrification to freeze embryos has allowed us to have high pregnancy rates but generalised success rates can be misleading due to the individuality of each patient’s situation. There are many hurdles to cross during treatment and it is wise to keep in mind that they all have to be successfully crossed to get to what we are all striving for – a baby to take home.
Success rates can be affected by many factors, including: