The relationship between a novel evaluation parameter of premature luteinization and IVF outcomes

RESEARCH QUESTION

Can premature luteinization of granulosa cells (PLGC) act as a novel parameter of premature luteinization and affect IVF outcomes?

STUDY DESIGN

In this retrospective cohort study, infertile patients undergoing fresh IVF cycles between January 2006 and December 2016 at the Reproductive Medicine Center in Tongji Hospital were included. A total of 42,468 cycles were conducted. Propensity score matching was carried out to match the baseline characteristics, and participants were assigned to the PLGC group and control group. The main outcomes were pregnancy rate and live birth rate.

RESULTS

Patient characteristics and clinical outcomes were compared before and after matching. In general, the fate of oocytes in the PLGC group was much worse than those in the control group after matching, including metaphase II rate, two-pronuclei rate, available embryo rate, blastocyst formation rate, high-quality blastocyst rate, pregnancy rate, implantation rate and live birth rate. Among those potential risk factors, gonadotrophin duration, oestradiol and progesterone on HCG day were positively associated with the occurrence of PLGC in the multivariate logistic regression model, with gonadotrophin dosage negatively related. Moreover, cumulus-oocyte complexes with PLGC showed a high correlation with elevated progesterone levels over 1.5 ng/ml.

CONCLUSIONS

Our findings demonstrated the adverse effect of PLGC on oocyte competency. In evaluating cumulus-oocyte complexes, PLGC provide an available novel parameter for premature luteinization judgement in clinical and individualized precise treatment. Close monitoring of progesterone level as well as critical analysis of progesterone elevation can reduce the occurrence of premature luteinization.

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.