Abstract
The impact of premature elevation of progesterone (PPE) on the day of the trigger on pregnancy outcome in in vitro fertilisation (IVF) cycles has been a matter of contention and debate for decades. Research over the last 30 years has indicated that PPE >1.5 ng/ml is associated with declining live birth rates following fresh embryo transfer. Freeze-only approach has become a universal solution to overcome the issue of PPE. However, the topic is still mired with controversy. Few studies have not shown a negative impact on pregnancy rates. The impact of PPE on embryological parameters such as oocyte and embryo quality and ploidy is still very controversial. An important contentious issue is the choice of the threshold P value above which it is considered abnormal and a freeze-all strategy would be cost-effective. Currently, though a cutoff of >1.5 ng/ml is widely used, practices are not uniform and varying thresholds from 0.4 to 3 ng/ml are utilised. This review addresses the current understanding of PPE in IVF and the above controversies. The incidence, aetiology and source of progesterone rise, impact on endometrial receptivity, oocyte and embryo quality, impact on live birth and cumulative live birth and impact on frozen embryo transfer and donor oocyte cycles are discussed. Current controversies regarding the optimal threshold, assay performance and future directions are addressed.