Preventing Growth Stagnation and Premature LH Surge Are the Keys to Obtaining a Viable Embryo in Monofollicular IVF Cycles: A Retrospective Cohort Study

Abstract

How LH levels influenced the outcomes of monofollicular IVF cycles using different stimulation protocols was controversial. In this single-center, retrospective study, we analyzed 815 monofollicular IVF cycles between 2016–2022 using natural cycle (NC), medroxyprogesterone acetate (MPA) or clomiphene citrate (CC) in addition to human menopausal gonadotropin (hMG), with or without GnRH antagonist. A viable embryo was obtained in 35.7% of all cycles. Growth stagnation and premature LH surge are two markedly negative factors for obtaining viable embryos (odds ratios of 0.12 [0.08–0.65], p < 0.0001 and 0.33 [0.26,0.42], p < 0.0001, respectively). NC/hMG cycles are prone to premature LH surge (40.4%), yielding a significantly lower opportunity of obtaining embryos (24.7%, p = 0.029). The administration of GnRH antagonist on the background of MPA resulted in a significant decrease in LH levels (from 2.26 IU/L to −0.89 IU/L relative to baseline, p = 0.000214), leading to a higher risk of growth stagnation (18.6%, p = 0.007). We hypothesized that the abrupt decline of LH might increase the risk of apoptosis in granulosa cells. We proposed a “marginal effect” framework to emphasize that the change of LH was the key to its bioactivity, rather than the traditional “window” concept with fixed cutoff values of a threshold and a ceiling.

Optimal timing of GnRH antagonist initiation in IVF-ET: a retrospective cohort study on advanced maternal age women

“…In terms of premature LH surge rate, the two strategies showed a similar result (23.1% vs 25.2%, P=0.730), but the women in our study seem more likely to have premature LH surge during COS compared with previous studies ( 15 – 17 ). Numerous studies have reported low serum LH level ( 18 , 19 ), as well as high serum LH level during COS ( 9 , 19 ), would impair pregnancy and live birth outcomes. When it comes to the choice of GnRH-ant initiation strategy, according to previous studies, the inhibition effect of GnRH-ant on LH level did not differ between fixed or flexible GnRH-ant protocols, which are in accordance with our results ( 16 , 17 ).…”