GnRH agonist ovulation trigger and hCG-based, progesterone-free luteal support: a proof of concept study

It is now well established that a GnRH agonist (GnRHa) ovulation trigger completely prevents ovarian hyperstimulation syndrome. However, early studies, using conventional luteal support, showed inferior clinical results following a GnRHa trigger compared with a conventional hCG trigger in normal responder IVF patients. We here present a novel approach for luteal support after a GnRHa trigger. METHODS Normal responder patients who failed at least one previous IVF attempt, during which a conventional hCG trigger was used, were consecutively enrolled in the study. A GnRH antagonist-based ovarian stimulation protocol was used in combination with a GnRHa trigger (Triptorelin 0.2 mg). The luteal phase was supported with a total of two boluses of 1500 IU hCG: on the day of oocyte retrieval and 4 days later. Neither progesterone nor estradiol was administered for luteal support.

The mean age was 33.8 years. The mean (± SD) numbers of oocytes and fertilized oocytes were 6.7 (± 2.5) and 3.6 (± 1.7), respectively. All 15 patients had embryo transfers and 11 patients conceived. On the day of pregnancy test (14 days after retrieval), the mean serum E(2) and progesterone levels were 6607 (± 3789) and 182 (± 50) nmol/l, respectively. Of the pregnancies, seven are ongoing, while four ended as miscarriages.

These preliminary results suggest that two boluses of 1500 IU hCG revert the luteolysis after a GnRHa trigger in the normo-responder patient. Importantly, no additional luteal support is needed. The novel concept combines the potential advantages of a physiological dual trigger (LH and FSH) with a simple, patient friendly, luteal support.