Short protocol – antagonist protocol – scheme 4
At day 2 or 3 in natural cycle stimulation may be introduced if neither cysts or endometrium is present by ultrasonography stimulation is initiated (Gonal F, Puregon or Menopur).
Approx five-to seven days later antagonist is added (Orgalutran or Cetrotide). This antagonist hinders secretion of ovulatory hormone LH.
The follicular growth is controlled by ultrasongraphy. When follicles are mature ovulation is induced by hCG injection (Pregnyl or Ovitrelle).
This protocol is suited for younger women and for these with PCO as the risk of Ovarian Hyperstimulation is reduced.
Control of ovarian cyst is poor by the protocol compared to no 3 and it is more difficult to use in combination with travelling plans. Still not as efficient as no 3 in pregnancy outcome, but appears less demanding to fulfil for the patients.