Why we use drugs in IVF
- Why we use drugs
- Why drugs are necessary
- Do the IVF drugs reduce my ovarian reserve?
- Possible side effects of IVF drugs
- Which drugs are used?
Why we use drugs
It has been shown that pregnancy success rates following IVF increase when more than one good quality embryos are transferred to the uterus. However, embryos formed after IVF do always have the desirable quality. Therefore, in order to have the ability of selection, we need several embryos, which will derive from the fertilisation of several eggs. The eggs, in turn, will be retrieved from several follicles. We therefore use drug protocols of controlled ovarian stimulation to promote the development of multiple follicles.
Why drugs are necessary
The drugs used are analogues of natural hormones in order to create a pharmaceutically controlled reproductive cycle. They aim at the following:
- The recruitment and maturation of multiple follicles
- To prevent untimely ovulation and loss of eggs due to early rise of LH. The drugs temporarily disrupt the communication between the pituitary and the ovaries leadin to downregulation of the glands (using GnRH agonists or antagonists)
- The selection of the ideal time of ovulation (with the application of hCG)
- To modulate the uterine environment for the support of the embryo (use of progesterone)
Do the IVF drugs reduce my ovarian reserve?
No, as the drugs rescue and promote the maturation of follicles that would otherwise degenerate through atresia. Atresia is the degeneration of follicles initially recruited in a single menstrual cycle.
It is worthwhile noting that the ovary contains approximately 300-400.000 follicles, of which only 400 mature during a woman's reproductive life (the rest degenerate via atresia, i.e they become atretic).
Possible side effects of IVF drugs
Mild symptoms from certain drugs and rare allergic reactions (hot flushes, headaches, sweating, blocked nose) are practically insignificant and can be easily overcome.
Ovarian hyperstimulation syndrome (OHSS) is a side effect of controlled ovarian stimulation. It occurs in a small percentage of women beginning treatment. In the majority of cases it can be prevented and when it occurs it can be treated.
The danger of subsequent ovarian, uterine or breast cancer is similar with the general population as demonstrated by large epidemiological studies.
Also see: Ovarian Hyperstimulation syndrome
Which drugs are used?
The main drugs used are:
Pharmaceutical analogues of the hormone GnRH intend to inhibit the premature rise of LH that causes ovulation. In this way we are able to prevent the undesirable rupture of follicles before the egg collection. In the past, before the use of GnRH analoguesabout 20-33% of cycles were cancelled due to premature ovulation.
GnRH analogues are classified in two categories:
- GnRH agonists (trade names: Arvecap, Daronda, Suprefact, Gonapeptyl) and
- GnRH antagonists (trade names: Orgalutran, Cetrotide)
They are synthetic pituitary gonadotrophins and are applied in order to stimulate the development and maturation of multiple follicles. They are classified in the following categories:
- Recombined gonadotrophins (recFSH, recLH)
Puregon (recombined FSH)
Gonal-F (recombined FSH)
Pergoveris (mixture of recombinant FSH, recombinant LH)
- Urinary gonadotrophins (hMG)
Altermon (purified FSH)
Metrodin-HP (purified FSH) and
Μerional – Bravelle (hMG with FSH-LH mixture)
- Corifollitropin- α (corifollitropin alpha, with commercial name Elonva)
See more: Gonadotrophins
Human chorionic gonadotrophin (hCG)
This is the last drug to inject during your treatment. It is applied once at a specific time (36-38 hours before egg collection), when the maturity of the follicles is adequate. Drugs: Ovitrelle (recombined hCG) and Pregnyl, Profasi (urinary hCG)
These drugs are available in several forms:
- ready to use injectable solution
- powder that is mixed with a special diluent to produce the final solution
- pre-filled cartridge or pen-like syringe
Injections are given subcutaneously or intramuscularly, depending on the instructions given. The pen is graduated in international units so you can apply the drug yourselves with precision and safety.
It is usually used after the embryo transfer to hormonally support the luteal phase and therefore the environment of the uterus that will receive the embryo. It is available as a vaginal cream (Crinone) or pills (Ultrogestan).
Other medicines like estrogens, cortisone, antibiotics and aspirin may be used if deemed necessary. In some cases contraceptive pills are used before the start of the treatment program.