Reproductive Axis Recovery Post Ovarian Stimulation and Gonadotropin Releasing Hormone Agonist (GnRH-a) Trigger, Observational Case Series
Triptorelin may delay ovulation by about one week in the natural cycle following ovarian stimulation, which could affect the timing of frozen embryo transfers.
Where it sits
this study against the rest of the triptorelin corpusSummary and findings
This observational case series examined the impact of Triptorelin (0.2 mg) on the reproductive axis following ovarian stimulation in 100 IVF patients. The study found that ovulation occurred later than expected in the subsequent natural cycle. Specifically, ovulation was delayed to cycle day 21, compared to the predicted cycle day 14.
Abstract
Background: Following GnRH agonist trigger and "freeze all" in order to prevent ovarian hyperstimulation syndrome (OHSS), patients are usually anxious to continue immediately with a frozen embryo transfer (FET). Currently, the preferred FET protocol in based on natural or induced ovulation. Objectives: Do ovarian stimulation and GnRH-a, used to trigger final oocyte maturation, affect the reproductive axis in the next natural cycle? Design: An observational case series of 100 subsequent IVF patients to whom GnRH-a (Triptorelin 0.2 mg) was given for final oocyte maturation in the context of ovarian hyper-stimulation syndrome prevention, followed by embryos "freeze all". Methods: In the next natural cycle, patients were followed to detect a dominant follicle (≥17 mm), at which time ovulation was triggered with hCG (250 µg), and FET was scheduled according to embryo's age on freezing day. Results: Whereas natural ovulation according to pre-IVF treatment was predicted to be on cycle day 14, the actual ovulation in our patients was on day 21. In eight patients follicular activity was not detected after 15-28 days, therefore the natural cycle frozen embryo transfer approach was abandoned. Conclusions: Ovarian stimulation and GnRH-a used to trigger final oocyte maturation in IVF patients inhibits the reproductive axis for days. Therefore, natural ovulation in the subsequent cycle may be deferred for about one week relative to the patient's pre-IVF menstrual cycle pattern.