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Figure 3 | Reproductive Biology and Endocrinology

Figure 3

From: The physiology of follicle selection

Figure 3

Physiological basis of ovarian hyperstimulation. Panel A illustrates the conventional mechanism of ovarian hyperstimulation in which concentrations of circulating FSH are elevated above threshold levels either by direct administration of exogenous FSH or by interfering with the negative feedback actions of estrogen on FSH secretion either by the administration of anti-estrogens or aromatase inhibitors. The number of preovulatory follicles increases but in an asynchronous manner owing to the asynchronous nature of preantral follicular development. Panel B illustrates a hypothetical way to provide a more synchronous population of preovulatory follicles by increasing the number of preantral follicles prior to elevating FSH concentrations and substituting FSH with LH when an appropriate number of follicles are selected.

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