The aim of hormonal controlled ovarian hyperstimulation is off course to increase pregnancy chance and birth rate. Man is a bad breeder considered as part of the mammalian species. If man were used for breeding, this would be done around the age 13-23 years og age. Since treatment in this age group, normally isn’t actual, we have to create a better milieu artificially to increase conception chance.
By controlled ovarian hormonal stimulation, the aim is to increase the number of available mature egg cells in one cycle. By creating more egg cells in one cycle, we have a better possibility to create more fertilised eggs – and more embryos yielding possibilities for choosing the best embryos for transfer The number we like to reach are at least 4 follicles preferable 8- 14 follicles.
Hormonal dosage
During the last 10 years or more we have been exponent for the idea of keeping the hormone dosage as low as possible as we do find lower pregnancy chance if eggs are generated on too high a dosage. It has even been demonstrated that higher stimulation doses may yield higher number of chromosomal aberrations. Though we have found a lower number of chromosome trisomies in our off spring generated in our clinic that expected.
Hormons used
Pergotime or clomivid citrat, called CC. CC or Pergotime increases the secretion of pituitary FSH and LH.
Synarela, Suprecur, Suprefact, Decapeptyl or Zoladex. These pituitary regulatory hormones posses dual effect: they may hinder premature LH peak and by that hinder premature ovulation. However, these hormones also add to the stimulatory effect of FSH and thereby yields a higher egg number when combined with FSH than FSH creates alone without these.
The stimulation per se is done with FSH – either recombinant ( Gonal F or Puregon) or by urinary derived hormone Menopur (HMG hormone). The recombinant FSH yields more egg per unit used than HMG. HMg could be favourable if OHSS may be a risk. Ovulation induction – the dormen contains hCG and two preparations are at sale: – Ovitrelle (250 mg ready to use equal to 6500 ie HCG and Pregnyl and old fasioned prescibtion with solvens and dry powder to mix (Pregnyl 5000 ie hCG). For IVF we normally use 10.000 ie.
Ultrasongraphy for monitoring the follicular groth rate
UltrIn average 8-12 eggs is optimal – but he number of possible eggs to retriev varies among women and with age. Individual doses are administered. Follicular develoment is monitored by ultrasongraphy as the egg cell itself is too small to visualise (0,12 mm I diameter). The egg bladder ie the follicle however is so large that the groth rate of these are monitored by transvaginal ultrasonography. At the time the follicles reaches 17-20 mm in average ovulation induction is given by hCG injection. 34-36 hours after hCG injection oocytes are collected by transvaginal oocyte pick up.
Stimulations protocols
Different protocols are used in the clinic. By increased knowledge the short protocol has improved in results and may be used more frequently even it is much more difficult to handle and is associated with high degree of cancellations among women aged 35 or more. To long distance stimulation the so called long protocol has a great advantage and still yields the best results in average. By this protocol it is facilitated to schedule travelling plans – cysts is better controlled and premature ovulation is hindered. After each control a definite plan to follow until next schedule at the clinic is handed out.
Side effects
Mostly only mild side effects are seen. The most frequent the claim is the form the hormone is administered: nasal spray several times a day is annoying to remember; injections daily may be a psychological problem etc. Serious side effects af ovarian hyper stimulation (called OHSS) is rarely seen among 2-3 % of the cycles. Long term side effects and risk does not exist (fortunately).