Tuesday, October 12, 2010
Failed fertilisation after IVF
Most IVF clinics are very good at making embryos in vitro, which means that for most patients, each IVF cycle results in the formation of embryos which they can admire.
( Tip: If you are doing IVF treatment, insist that the clinic give you photos of your embryos. This is the best documentation that you have received good quality medical care. You have a legal right to your medical records - every hospital has to provide them by law ! Please make a request for this in writing ! Poor quality documentation without photos of your embryos suggests you have received poor quality medical care !)
However, sometimes there is complete failure of fertilisation, as a result of which no embryos are formed. This can be a rude shock to the patient, and causes major heartburn !
Why do the sperm fail to fertiise the eggs in vitro in these patients ?
There are 3 possible sources of this problem: the eggs; the sperm ; and the Lab. Let's look at these one by one.
The commonest reason could be an egg problem. Poor quality, "tired" eggs will often fail to fertilise. This is true in older women ; and in those who have entered the oopause. Even though the structure of the eggs looks fine ( which means that under the microscope, their morphology is normal), they simply do not have the competence to fertilise and form embryos. Remember that the energy for fertilisation and cleavage comes from the mitochondria ( the power houses of the cells); and in older women, sometimes the mitochondria are just not able to provide the energy which allows the formation of the cell spindle.
We also see this in younger women who have PCOD. Doctors are often so scared of OHSS, that they end up mistiming the HCG injection, as a result of which they get few eggs and poor quality embryos.
What about sperm problems ? There are men who have very good sperm counts and motility, but whose sperm are not functionally competent; and cannot fertilise the eggs in vitro. Unfortunately, there is no way of predicting this in advance - and total failed fertilisation provides important diagnostic information that the " unexplained infertility " in this case was because of an undiagnosed male factor. The good news is that it's easy to treat this problem ( but only in the next treatment cycle) by doing ICSI. While it is possible to attempt rescue ICSI with these unfertilised eggs in the same treatment cycle, but the success rates with this are poor.
The third group of reasons is a poor quality lab. Thus, fungal contamination or bacterial infection in the IVF culture medium can kill all the eggs. A poorly equipped lab ( for example, one with malfunctioning incubators) will also have poor fertilisation rates. This can occur because of various other technical problems as well - such as electricity failure ; or the use of expired IVF culture medium. Unfortunately, it's very hard for a patient to find out if the failed fertilisation is because of a lab problem, because it's hard to get this information from the doctor.
Usually, if it's a lab problem, it should affect all the embryos of all the patients on that day. An important question to ask is - What happened to the other patient's embryos ? ( though this information may not be readily available ! ) The good news is that if the failed fertilisation is because of poor lab conditions, it's easy to fix this problem by finding a better IVF clinic for your next cycle.
A close examination of the eggs and sperm can give the doctor valuable information, which can help him to diagnose the problem and find the right solution . Are the eggs in the dish all immature ? Are the sperm in the IVF petri dish still motile after 24 hours ? ( If the sperm are all immotile, this suggests a problem with the IVF lab conditions). You should ask for photos of the unfertilised eggs. If they are dark, this suggests they have degenerated, which could be because of an infection.
What are the possible solutions ? If IVF was done, it's possible to do a rescue ICSI on the same day , though the success rates with this are not always good. The important thing is to use this hard-earned information to help in making decisions about the next treatment cycle !
You options include:
1. change the treatment. Instead of doing IVF, ICSI may be a better option, if the failed fertilisation was because of dysfunctional sperm
2. change the eggs. You might want to use donor eggs, if you have few poor quality eggs
3. change the clinic. This is often your best choice, as a new IVF expert will be able to look at the problem dispassionately and hopefully do a better job !