[Ghost]

Triggering with 5,000 instead of 10,000 hCG results in a modest decrease in the chance of OHSS.

Triggering early (e.g. 8 days) or coasting (using little or no FSH for the last few days before trigger) compromise the embryo cohort (many small follicles with typically yield lousy eggs). It is claimed that these approaches reduce OHSS incidence, but properly designed studies have not been performed to prove it.

A much better solution is to trigger with a GnRH agonist (like Lupron) instead of hCG. This induces an LH surge that matures the eggs much like it does in natural cycles. But the LH is short-lived (half life is around 1 hour, as opposed to 36 hours for hCG), so it does not keep stimulating the follicles for days afterward, like hCG does. With this approach, clinically significant OHSS is impossible or nearly so, so there is no need to play games with the stimulation and compromise the oocyte cohort.

Of course, you can use the GnRH agonist to trigger only if you are using an antagonist for pituitary suppression (basically, you would need to be in a ganirelix cycle). It won't do anything if you are already using Luporon for down regulation.

We have used this trigger hundreds of times, even on several patients with E2 well above 10,000. No OHSS yet.

The luteal support must start earlier and be more aggressive than with hCG cycles, if you are going to transfer fresh embryos in non-donor cycles following a Lupron trigger.

The current best study of this method is by Engmann et al (2008). Note the luteal support protocol.