The Effect of Luteinising Hormone Suppression in In Vitro Fertilisation Antagonist Cycles

Use of GnRH antagonists in IVF stimulation protocols shortens controlled ovarian hyperstimulation (COH) and reduces the risk of ovarian hyperstimulation syndrome (OHSS). However, profound reduction in LH levels has been associated with use of GnRH antagonists. This study aims to determine if LH suppression during GnRH antagonist cycles results in poorer IVF outcomes. This was a prospective pilot longitudinal study where serum LH levels were measured on day 2/3 of the menstrual cycle before COH, 1/2 days following institution of GnRH antagonist and at the day of ovulation trigger. A threshold of LH <0.5 IU/L was used to define profound LH suppression. Data on IVF outcomes was collected. Logistic regression analysis was used to investigate risk factors associated with LH suppression following GnRH antagonist IVF treatment. Ninety-one eligible women were recruited. Women underwent a standard antagonist cycle with Puregon 200u and Ganirelix. No participant had LH <0.5 IU/L prior to GnRH antagonist treatment, and 27 participants (29.7%) had significant LH suppression at either time point. Predictors of profound LH suppression following GnRH antagonist treatment identified (P < 0.20) were age (OR = 0.80, P = 0.013), no previous ovulation induction (OR = 0.26, P = 0.033) and previous GnRH antagonist IVF cycle (OR = 4.32, P = 0.125). Numbers of oocytes, embryos and ongoing pregnancy rates at 12 weeks gestation in patients with and without LH suppression did not differ significantly. We found associations between clinical characteristics and risk of profound LH suppression in women undergoing GnRH antagonist IVF cycles, but no significant differences in IVF and pregnancy outcomes between women with and without significant LH suppression.