If you and your partner are attending a Fertility Clinic in your efforts to have a baby, you are probably wondering about the IVF process. That’s the procedure that most people associate with clinics and Assisted Reproductive Technologies (ARTs).
While there are many alternatives to IVF which may instead be recommended by your specialist team, you will still want to know about IVF itself and what it entails. The IVF procedure is therefore the subject of this piece in our series of articles on what to expect at a fertility clinic.
Remember that whether attending for IVF, an alternative ART, or continuing to try to conceive naturally, pre-Conceive can help to best prepare both partners’ bodies for the process ahead.
Its unique combination of therapeutic levels of 31 essential nutrients and other ingredients has been shown to improve key fertility parameters in both women and men. By taking pre-Conceive, the man can produce a higher quality of sperm, and the woman can also become more fertile and better prepared for the pregnancy that will hopefully follow.
The IVF process
Whether taking pre-Conceive or not, the IVF process is as follows:
- Drugs are used to suppress natural ovarian function, and then the ovary is stimulated by injections of gonadotrophin.
- Ova (eggs) are collected vaginally, by means of an ultrasounddirected probe.
- The male partner provides a sperm sample, and this is used to fertilise the ova in a laboratory.
- Three embryos are placed in the uterine cavity. This is the optimum number, providing the best chance of pregnancy, while avoiding the complications which might arise if larger numbers were used.
- A pregnancy test is conducted some weeks later. This obviously tells whether or not the process has been successful.
Why are three embryos used?
Firstly, in the UK, the law limits to three the number of embryos which may be placed in the uterine cavity in any one cycle. Some units now prefer to use two, and say they achieve the same success rates as were gained previously using three. However, three is the number normally considered to be both most safe and effective.
Typical success rates of the IVF process
Unfortunately, in approximately 75% of IVF processes, successful implantation will not occur. However, where three embryos are used, the success rate in terms of pregnancies achieved may be up to 30%. A significant proportion of these are twin pregnancies.
In terms of live births, the success rate is of the order of 15% to 20%. Some sources report that the success rate is not significantly less when frozen embryos are used. This obviously depends to some extent on the technology used. This is constantly being developed.
Note that the above figures refer to the success rate of the procedure. The embryo survival rate is significantly lower.
Let us assume that three embryos are used, in each of one hundred IVF cycles, and that thirty pregnancies occur, of whichone third are twin pregnancies. This means that, of the three hundred embryos placed in the uterine cavity, only forty (or 13%) actually survive to a stage at which pregnancy can be confirmed.
Natural cycle IVF process
An alternative to the above procedure is what is known as natural cycle IVF.
As the name suggests, no drugs are used to stimulate the ovary. Ova are harvested at the time of ovulation, fertilised in vitro using the husband’s sperm, and then placed in the uterine cavity.
The success rate using this method is significantly lower (at about 10%), but this reflects a significantly higher rate of survival of the individual embryo. There is no question of surplus embryos being generated.
Natural cycle IVF can be very tedious and unpredictable. There are, however, some signs that it may be possible in the future to mature ova in vitro, thus making the process less timesensitive.
What happens to surplus eggs?
In the UK and other jurisdictions, surplus fertilised ova can be frozen and may be used in subsequent cycles. With the consent of the biological parents, the law allows for these embryos to be placed in the womb of another woman, or to be used for research purposes.
UK law also provides for the disposal of unused embryos after a period of five years in storage.
In the Republic of Ireland, there is no law specifically governing IVF, but the Guide to Ethical Conduct and Behaviour includes a requirement that ‘any fertilised ovum must be used for normal implantation and must not be deliberately destroyed.’