In Vitro Fertilization
This method means a lot of expenses, stress and patience for a couple. It also means medical intervention. The most important though is that many people think that the IVF rates are extremely high and by the end of the therapy, they will have their baby in their arms.
There is no doubt that the purpose of a gynecologist specialized in IVF is the same to an infertile couple: childbearing. Furthermore, the specialist has to make sure that the procedure is safe for the woman, short and affordable.
It is very important for the couple to be informed about what IVF really means. Read more here
Given the number of embryos that can be legally tranfered in the uterus during the embryo transfer, which is the last IVF step, the success rate is between 45-48%.
But what does this number really mean?
This number refers to women under the age of 35 years old. After this age the success rates start dropping every year. For instance, a 40 year woman has a 12% chance of getting pregnant, whereas a 44 year old drops at 2-3%. It is important to note that the percentages mentioned above, as well as those mentioned below, refer to women on average regardless of their hormone profile. Also, if there are any anatomic abnormalities, previous failed cycles and partner’s sperm quality. Every couple has its own success rates that are impossible to define accurately. For this reason, evaluation is not always approximate but still estimated according to the percentages already mentioned.
Also, the total success rate for a woman (until 35 years old) undergoing the treatment three times, comes to 70%.
The next unknown factor of these percentages are their true meaning. Let’s say we have a woman of 34 years. The IVF success rate is 45%. What does it mean? Pregnancy success rates may refer to a positive pregnancy test (biochemical pregnancy). Or to the detection of foetal heart beat via ultrasound, a few weeks after completing a treatment cycle (clinical pregnancy). However, during the first weeks of pregnancy, a significant percentage of conceptions never reach the heart beat at the beginning stage. So we see that biochemical pregnancy success rates are significantly higher compared to clinical pregnancy success rates.
It becomes even more complicated when considering the IVF live birth success rates (take home baby rate).
Among pregnant women, the miscarriage rate is about 15%. The rate of miscarriage drops as the pregnancy is progressing well. But it is still different for every woman and increases depending on maternal age. This happens because of the high frequency of chromosomal abnormalities. Moreover, the miscarriage rate for women undergoing IVF treatment is about 20%. This is due to the fact that these women encounter pregnancy complications more often and are categorized as high risk pregnancies. So, we notice that the IVF birth success rates are even lower.
We also understand that the procedure is even more complicated when we think of those women undergoing IVF treatment that never reaches to the stage of embryo transfer. Even though they start ovarian stimulation, their cycle is cancelled due to many reasons. For instance no response to medical ovarian stimulation and no collected oocytes (empty follicle syndrome). Other reasons may be no egg fertilization by spermatozoa (failed fertilization), no embryo transfer, or because of anatomic abnormalities.
Of course, the cases we mentioned above do not occur altogether, but one per case. However, each one of these facts reduces the success rates. If success rates include all women initiating an IVF treatment, then percentages are considerably lower compared to those including only women that successfully reached the embryo transfer stage. Because, the latter group of women has overcome the risk of dropping out of IVF treatment.
Moreover, embryo quality plays an important role in IVF. The better the embryo morphology, the higher the success rates.
All the above become even more complicated if we take into account intra-cytoplasmic sperm injection (ICSI), blastocyst culture, oocyte in vitro maturation (IVM), natural cycles, preimplantation genetic diagnosis (PGD). Also, the use of cryopreserved oocytes, sperm or embryos, assisted hatching and ovarian stimulation protocols (short, long, ultra long and ultra-short), agonist or antagonist and recombinant or human gonadotropin administration make it even more difficult for us to understand.
The outcome is that success rates are different for each case of undergoing IVF treatment. We use statistics in many sciences (economics, politics) and whoever refers to statistics should be very careful, either the doctor, or the patient.
On one hand, the fertility specialist is responsible for avoiding to create unrealistic expectations. On the other hand, the couple has the right to know its own realistic per-cycle success rate. They must not take irrespective of international IVF pregnancy rates into account, because they may not coincide with the couple’s personalized predicted success rate and the specific assisted reproduction unit statistics report.
This doesn’t mean that international IVF statistics reports are useless. On the contrary, all IVF data provided by statistics are valid as they are extracted from a wide study population. In our country, where the population isn’t large, it is quite difficult to collect enough data.
It is important though to distinguish between overall success rates, and this specific assisted reproduction unit’s success rates, without forgetting each couple’s medical record and reasons of infertility.
In conclusion, the infertile couple should understand that Assisted Reproductive Technologies are not a panacea for overcoming infertility and cannot promise that a woman will get pregnant, even more taking a baby home. However, IVF is the most reliable and safe way of experiencing parenthood. In experienced hands, success rates are promising and every year is increasing, following scientific progress.