The progesterone positive feedback effect in women after ovariectomy

Outcomes and cost-effectiveness comparisons of progestin-primed ovarian stimulation, GnRH antagonist protocol, and luteal phase stimulation for fertility preservation

OBJECTIVE

To compare the clinical outcomes and cost-effectiveness of progestin-primed ovarian stimulation (PPOS) and the gonadotropin-releasing hormone-antagonist (GnRH-A) protocol in fertility preservation (FP) in cancer patients. The stimulation option when patients were in the luteal phase was also explored.

METHODS

This retrospective study analyzed clinical data from 163 patients who underwent FP. The number of retrieved oocytes and vitrified oocytes/embryos, total dose of gonadotropin, duration of stimulation, number of injections, and cost were compared among the PPOS, GnRH-A, and luteal phase stimulation (LPS) groups.

RESULTS

No significant differences were noted in the numbers of retrieved oocytes and vitrified oocytes/embryos among the three groups. In the multiple regression model, age (P = 0.02) and antral follicle count (AFC) (P < 0.001), but not the controlled ovarian stimulation (COS) protocols (P = 0.586), were associated with the number of retrieved oocytes. The number of injections and the cost were all significantly lower in the PPOS and LPS groups than in the GnRH-A group(P < 0.001).

CONCLUSION

PPOS had similar clinical results but was superior medically and economically to GnRH-A. For patients in the luteal phase, LPS was an optional protocol with similar outcomes and costs to PPOS.

Novel aspects of the endocrinology of the menstrual cycle

Ovarian control of gonadotrophin secretion is normally achieved via the feedback mechanisms mediated by oestradiol and progesterone. Evidence has been provided that nonsteroidal substances, such as inhibin A and B, participate in the negative feedback control of FSH secretion. Another nonsteroidal ovarian substance is gonadotrophin surge-attenuating factor (GnSAF), the activity of which is particularly evident in women undergoing ovulation induction. Accumulating evidence has suggested that GnSAF plays a physiological role during the menstrual cycle. In particular, this factor antagonizes the sensitizing effect of oestradiol on the pituitary response to gonadotrophin-releasing hormone during the follicular phase of the cycle. A hypothesis has been developed that, in the late follicular phase, the activity of GnSAF is reduced and this facilitates the sensitizing effect of oestradiol on the pituitary, thus enforcing the massive discharge of gonadotrophins at the midcycle LH surge. The interaction of oestradiol, progesterone and GnSAF on the hypothalamic-pituitary system provides a novel approach to explain the mechanisms which control LH secretion during the normal menstrual cycle. The ovarian control of gonadotrophin secretion during the normal menstrual cycle is achieved via negative and positive feedback mechanisms. The steroids oestradiol and progesterone are the main regulators; however, nonsteroidal substances, such as inhibin A and inhibn B, also participate. Accumulating evidence has demonstrated that another nonsteroidal ovarian substance, gonadotrophin surge-attenuating factor (GnSAF), plays a key role in the control of LH secretion during the follicular phase and at midcycle, providing thus a novel aspect in the ovarian control of gonadotrophin secretion during the human menstrual cycle. The ovarian control of gonadotrophin secretion during the normal menstrual cycle is achieved via negative and positive feedback mechanisms. The steroids oestradiol and progesterone are the main regulators; however, nonsteroidal substances, such as inhibin A and inhibn B, also participate. Accumulating evidence has demonstrated that another nonsteroidal ovarian substance, gonadotrophin surge-attenuating factor (GnSAF), plays a key role in the control of LH secretion during the follicular phase and at midcycle, providing thus a novel aspect in the ovarian control of gonadotrophin secretion during the human menstrual cycle.