Premature Progesterone Elevation Does Not Affect Pregnancy Outcome in High-Responder Patients Undergoing Short-Interval Coasting in IVF Cycles

Revisiting debates of premature luteinization and its effect on assisted reproductive technology outcome

The impact of the prematurely elevated serum progesterone on the late follicular phase, commonly known as premature luteinization (PL), is a matter of continuing debate. Available evidence supports that serum progesterone ≥ 1.5 ng/ml on the day of ovulation triggering could reduce the pregnancy potential in fresh in vitro fertilization (IVF) cycles by jeopardizing endometrial receptivity. Causes of PL during ovarian stimulation are unclear. Recent studies point toward the daily follicle-stimulating hormone dosage, duration of controlled ovarian stimulation, number of oocytes retrieved, and peak estradiol level as factors affecting the incidence of PL. Emerging data show additional influence on embryo quality. The prevention of PL has been challenging. The key elements in preventing PL include individualization of ovarian stimulation according to patient's ovarian reserve, proper ovulation trigger timing, and use of medications such as corticosteroids and metformin. Embryo cryopreservation with deferred embryo transfer is the established strategy to overcome PL, yet it is an extra burden to the IVF laboratory and increased cost for patients. Herein, we review the up-to-date knowledge of this frequent IVF problem including causes, proposed diagnostic criteria, and its impact on endometrial receptivity, embryo quality, and pregnancy outcomes. The preventive measures and rescue strategies are also discussed.

The curious case of premature luteinization

PURPOSE

Premature luteinization (PL) affects 12.3-46.7% of fresh in vitro fertilization cycles, and there is accumulating evidence confirming its negative effect on success rates. However, despite its clinical significance, PL is poorly understood and defined. This narrative review aims to provide a fresh look at the phenomenon of PL by summarizing the existing evidence and re-evaluating fundamental issues.

METHODS

A thorough electronic search was conducted covering the period from 1978 until January 2018 in PubMed, Embase, and Medline databases, and references of relevant studies were cross-checked. Meeting proceedings of the European Society of Human Reproduction and Embryology and the American Society for Reproductive Medicine were also hand searched.

RESULTS

In the curious case of PL, one should go back to the beginning and re-consider every step of the way. The pathogenesis, definition, measurement methods, clinical implications, and management strategies are discussed in detail, highlighting controversies and offering "food for thought" for future directions.

CONCLUSIONS

Authors need to speak the same language when studying PL in order to facilitate comparisons. The terminology, progesterone cut-off, measurement methods and days of measurement should be standardized and globally accepted; otherwise, there can be no scientific dialog. Future research should focus on specific patient profiles that may require a tailored approach. Progesterone measurements throughout the follicular phase possibly depict the progesterone exposure better than an isolated measurement on the day of hCG. Adequately powered randomized controlled trials should confirm which the best prevention and management plan of PL is, before introducing any strategy into clinical practice.

The high responder: a review of pathophysiology and outcomes during IVF treatment

This review attempts to summarize the known literature on high responders to ovarian stimulation during assisted reproductive techniques (ART). Response to gonadotrophins is subject to significant interindividual and intercycle variation, thus carrying a risk of high response or poor response to ovarian stimulation regimens. The main risk for high responders is the development of ovarian hyperstimulation syndrome (OHSS) which is associated with significant morbidity. Hence, the definition of high responders in the literature has primarily focussed on risk factors for OHSS. Strategies to reduce OHSS including tailoring of the ovarian stimulation regimens and adjusting gonadotrophin doses according to patient characteristics and findings during the cycle of stimulation. In addition, modifying the type of ovulation trigger used and adjuvant therapies, such as metformin, intravenous colloids and vascular endothelial growth factor blockers, have also been studied as options to reduce OHSS. Apart from the risk of OHSS, high response also appears to have an adverse impact on the oocyte and endometrium, though there is a paucity of data regarding the extent and mechanisms behind this impact.