Plasma gonadotrophin and ovarian steroid concentrations in women with menstrual cycles with a short luteal phase

The true natural cycle frozen embryo transfer - impact of patient and follicular phase characteristics on serum progesterone levels one day prior to warmed blastocyst transfer

BACKGROUND

In a true-natural cycle (t-NC), optimal progesterone (P4) output from the corpus luteum is crucial for establishing and maintaining an intrauterine pregnancy. In a previous retrospective study, low P4 levels (< 10 ng/mL) measured one day before warmed blastocyst transfer in t-NC were associated with significantly lower live-birth rates. In the current study, we aim to examine the relationship between patient, follicular-phase endocrine and ultrasonographic characteristics, and serum P4 levels one day prior to warmed blastocyst transfer in t-NC.

METHOD

178 consecutive women undergoing their first t-NC frozen embryo transfer (FET) between July 2017-August 2022 were included. Following serial ultrasonographic and endocrine monitoring, ovulation was documented by follicular collapse. Luteinized unruptured follicle (LUF) was diagnosed when there was no follicular collapse despite luteinizing-hormone surge (> 17 IU/L) and increased serum P4 (> 1.5 ng/mL). FET was scheduled on follicular collapse + 5 or LH surge + 6 in LUF cycles. Primary outcome was serum P4 on FET - 1.

RESULTS

Among the 178 patients, 86% (n = 153) experienced follicular collapse, while 14% (n = 25) had LUF. On FET-1, the median serum luteal P4 level was 12.9 ng/mL (IQR: 9.3-17.2), ranging from 1.8 to 34.4 ng/mL. Linear stepwise regression revealed a negative correlation between body mass index (BMI) and LUF, and a positive correlation between follicular phase peak-E2 and peak-P4 levels with P4 levels on FET-1. The ROC curve analyses to predict < 9.3 ng/mL (< 25th percentile) P4 levels on FET-1 day showed AUC of 0.70 (95%CI 0.61-0.79) for BMI (cut-off: 23.85 kg/m2), 0.71 (95%CI 0.61-0.80) for follicular phase peak-P4 levels (cut-off: 0.87 ng/mL), and 0.68 (95%CI 0.59-0.77) for follicular phase peak-E2 levels (cut-off: 290.5 pg/mL). Combining all four independent parameters yielded an AUC of 0.80 (95%CI 0.72-0.88). The adjusted-odds ratio for having < 9.3 ng/mL P4 levels on FET-1 day for patients with LUF compared to those with follicle collapse was 4.97 (95%CI 1.66-14.94).

CONCLUSION

The BMI, LUF, peak-E2, and peak-P4 levels are independent predictors of low serum P4 levels on FET-1 (< 25th percentile; <9.3 ng/ml) in t-NC FET cycles. Recognition of risk factors for low serum P4 on FET-1 may permit a personalized approach for LPS in t-NC FET to maximize reproductive outcomes.

Irregular ovarian cyclicity is associated with adrenal activity in female eastern black rhinoceros (Diceros bicornis michaeli)

To achieve self-sustaining and genetically diverse populations ex situ, captive breeding programmes must ensure good overall rates of reproduction, and equal contribution across individuals. Previous research in the critically endangered eastern black rhinoceros (Diceros bicornis michaeli) revealed a high incidence of irregular oestrous cyclicity; in particular extended cycle duration among nulliparous females and acyclic periods in parous females that have not bred for several years. Irregular ovarian activity could play a role in reduced reproductive output; however, the mechanisms underlying these anomalies are poorly understood. The aim of this study was to measure faecal glucocorticoid metabolite (fGCM) concentrations and variability prior to and during periods of regular and irregular ovarian activity, and determine if adrenal activity influences the occurrence of different cycle types in this species. Faecal samples were collected every other day from parous (N = 6) and nulliparous (N = 12) females at eight European institutions for periods of 9-15 months. Concentration and variability in fGCM were compared between periods of regular and irregular cyclicity and between different cycle types (<20 days, 20-40 days, >40 days, acyclic) using generalized linear mixed models. Concentrations of fGCM were influenced by season and higher during the luteal than the follicular phase of the oestrous cycle. Taking this into account, fGCMs were increased during periods of irregular cyclicity (all types combined and during cycles >40 days in length) compared to 20-40 day cycles. This was predominantly driven by nulliparous females. The variation in fGCM concentration also differed between periods of regular and irregular cyclicity; higher standard deviation in fGCM preceded irregular cycles and >40 day cycles compared to 20-40 day cycles. These results suggest that although fGCM concentrations fluctuate across the oestrous cycle in this species, changes in adrenal activity at specific times could be one factor associated with irregular ovarian activity in the black rhinoceros.

Darwin's legacy: an evolutionary view of women's reproductive and sexual functioning

On the Origin of species, published just over 150 years ago, has deeply influenced thinking in both scientific and wider communities. Darwin's legacy includes recognition of the fact that all organisms evolve; that variation within and between species is natural and normal; and that an evolutionary approach to understanding the sources and consequences of this variation comprises theoretical frameworks, testable hypotheses, and rigorously collected evidence. With an eye toward facilitating communication and productive collaboration among researchers from different intellectual traditions who nonetheless share a common interest in women's reproductive and sexual functioning, we discuss evolutionary concepts and models, summarize the known variability in ovarian functioning and consider the implications of this variability for conducting sex research, and evaluate the relative merits of various biomarkers that serve as proxy measurements of a woman's reproductive and hormonal status. With these perspectives and methods from reproductive ecology at hand, we examine several contentious issues: the links between hormones and sexuality in premenopausal and perimenopausal women, the causes of premenstrual syndrome, and the existence (or not) of menstrual synchrony. In none of these cases is as much known as is often claimed. In each, there are abundant opportunities for innovative, albeit challenging, research.

A phase plane graph based model of the ovulatory cycle lacking the "positive feedback" phenomenon

When hormones during the ovulatory cycle are shown in phase plane graphs, reported FSH and estrogen values form a specific pattern that resembles the leaning “&" symbol, while LH and progesterone (Pg) values form a "boomerang" shape. Graphs in this paper were made using data reported by Stricker et al. [Clin Chem Lab Med 2006;44:883–887]. These patterns were used to construct a simplistic model of the ovulatory cycle without the conventional "positive feedback" phenomenon. The model is based on few well-established relations:

hypothalamic GnRH secretion is increased under estrogen exposure during two weeks that start before the ovulatory surge and lasts till lutheolysis.

the pituitary GnRH receptors are so prone to downregulation through ligand binding that this must be important for their function.

in several estrogen target tissue progesterone receptor (PgR) expression depends on previous estrogen binding to functional estrogen receptors (ER), while Pg binding to the expressed PgRs reduces both ER and PgR expression.

Some key features of the presented model are here listed:

High GnRH secretion induced by the recovered estrogen exposure starts in the late follicular phase and lasts till lutheolysis. The LH and FSH surges start due to combination of accumulated pituitary GnRH receptors and increased GnRH secretion. The surges quickly end due to partial downregulation of the pituitary GnRH receptors (64% reduction of the follicular phase pituitary GnRH receptors is needed to explain the reported LH drop after the surge). A strong increase in the lutheal Pg blood level, despite modest decline in LH levels, is explained as delayed expression of pituitary PgRs. Postponed pituitary PgRs expression enforces a negative feedback loop between Pg levels and LH secretions not before the mid lutheal phase.

Lutheolysis is explained as a consequence of Pg binding to hypothalamic and pituitary PgRs that reduces local ER expression. When hypothalamic sensitivity to estrogen is diminished due to lack of local ERs, hypothalamus switches back to the low GnRH secretion rate, leading to low secretion of gonadotropins and to lutheolysis. During low GnRH secretion rates, previously downregulated pituitary GnRH receptors recover to normal levels and thus allow the next cycle.

Possible implications of the presented model on several topics related to reproductive physiology are shortly discussed with some evolutionary aspects including the emergence of menopause.

The differential effects of FSH and LH on the human ovary

The basic foundation for normal puberty and adult reproductive function is established during fetal life with the adequate development of the hypothalamus, pituitary and gonads. Further maturation and differentiation of the hypothalamic-pituitary-gonadal axis continues throughout childhood, puberty, adult life and senescence. Pituitary FSH and LH play a central role in the cascade of events in the hypothalamic-pituitary-gonadal axis by mediating between the brain and hypothalamus on one hand and the end-organ, the ovary, on the other. Absent or low pituitary secretion of FSH and LH, as occurs in hypothalamic/pituitary hypogonadism, leads in women to anovulation, amenorrhoea and absent ovarian follicular development. The ability of gonadotrophins to modulate ovarian function depends on their rate of synthesis by the pituitary gonadotrophs, on their circulating concentrations (which vary throughout life and throughout the menstrual cycle), on the relative abundance of the multiple forms of gonadotrophins that have varying biological activity, on the presence of their receptors on the different cell types of the ovary, on the intracellular adenylate cyclase enzyme that causes the production of cAMP, and on the extra- and intragonadal factors that are able to modulate the effects of gonadotrophins in the ovary. Recent clinical and basic research with recombinant gonadotrophins, molecular biological studies on the localization, function and regulation of the long sought after gonadotrophin receptors, as well as research on the interaction between gonadotrophins and local intragonadal factors have widened our knowledge about the function and role of FSH and LH in the ovary and have provided new insights into previously unanswered questions of ovarian physiology and pathophysiology and will provide the basis for the design of new treatment strategies to overcome ovulatory gonadotrophin-dependent dysfunction in the future.

Measurements of salivary progesterone throughout the menstrual cycle in women suffering from unexplained infertility reveal high frequency of luteal phase defects

Forty-five women suffering from unexplained infertility collected saliva for progesterone (P) measurements every morning during 1 to 3 complete cycles. A total of 27 cycles analyzed were unstimulated, 19 were stimulated by clomiphene citrate (CC), and 7 with CC, human menopausal gonadotropin (hMG), and human chorionic gonadotropin (hCG). Compared with reference profiles of salivary P from 27 normal cycles, the length and magnitude of P secretion were significantly lower in the infertility group. Luteal P concentrations were normalized during CC stimulation and significantly elevated during the CC-hMG-hCG stimulation. The other abnormalities found in the salivary P profiles of these patients included preovulatory P peaks, interruption of P secretion during luteal phase, and high P level at the beginning of menstruation. The results suggest that patients with prolonged unexplained infertility represent a heterogenous population with common luteal phase defects. The disturbance is effectively corrected with treatments stimulating gonadotropin secretion.

Daily measurements of salivary progesterone reveal a high rate of anovulation in healthy students

Daily concentrations of salivary progesterone (P) were measured from 32 women during a complete menstrual cycle. Seventeen of the subjects were university students and 15 were patients of an infertility clinic (a severe male-factor was verified as the cause of infertility in all of them). Commercially available reagents for radio-immunoassay of serum P were modified for salivary measurements, to yield acceptable precision and sensitivity (40 pmol/l). Good correlation (r = 0.93) was found between salivary and serum P concentrations in samples collected simultaneously. The follicular phase levels of salivary P were below 100 pmol/l, and those at the luteal peak were 390 +/- 45 pmol/l (mean +/- SEM, n = 24). From the menstrual salivary P concentration curves we identified the first day of significant elevation above mean follicular levels (T2) and thereafter calculated the cumulative sum of daily P concentrations until 95% of the luteal phase secretion had accumulated (C95). The time needed to reach C95 (designated T95) and logC95 were plotted in coordinates and used as the basis of evaluation of normal menstrual P secretion. The observations were distributed in two groups, one with clearly identifiable T2 and a distinct luteal-phase P (ovulation had occurred) and one with no identifiable T2 and absent luteal-phase P peak (indicative of anovulation). Interestingly, 47% of the student population had an abnormally low menstrual P profile while all the other subjects displayed a clear luteal-phase peak of salivary P. These data provide more evidence for applicability of salivary P measurements for diagnosis of corpus luteam function and highlight the difficulty of selecting representative reference populations in studies on female reproductive endocrinology.

The diagnosis of luteal phase deficiency: a critical review

Luteal phase deficiency is an ovulatory dysfunction problem that is subtle but real. It may be the most common ovulatory problem in women. Luteal phase deficiency has been clearly demonstrated in the research setting (1) in spontaneous cycles, (2) when follicular maturation has been impeded, and (3) when luteotrophic influences have been suppressed. The diagnosis of LPD in the clinical setting remains problematic and controversial primarily because there is no practical diagnostic method that has been validated. This article has reviewed the methods that have been used to diagnose LPD. BBT charts are insensitive; these charts reliably diagnose LPD only when there are persistent short luteal phases. There is disagreement whether ovarian follicular size, as determined by ultrasonography, is decreased in LPD; however, ultrasonographic diagnosis of LPD would require daily scans through ovulation, which makes this approach impractical. Mild hyperprolactinemia is a probable cause of LPD in a minority of patients; a physician should obtain a PRL level in LPD women with the realization that there is considerable sampling variability. Determination of serum gonadotropin levels (LH or FSH or both) is not practical for the clinical diagnosis of LPD. Random serum P levels, whether single or multiple, are not helpful in the diagnosis of LPD in individual patients. The secretory pattern of P results in such wide confidence limits that P samples from individuals cannot be compared to normal in a useful manner. Most of the controversy about the diagnosis of LPD has centered around the use of individual serum P levels. The timed endometrial biopsy relies on the endometrium as a bioassay of P over time. The endometrial biopsy has not been carefully validated in terms of its sensitivity or accuracy for the diagnosis of LPD. However, it remains the best current method for the diagnosis of LPD when the standard guidelines for its use are followed. As opposed to the other tests for LPD, awareness of the usefulness of the biopsy has increased as we have learned more about CL physiology. No current research method for the diagnosis of LPD appears to be a practical method that could be applied in the clinical setting. Specific secretory proteins from the endometrium and methods to measure hormone secretion that circumvent the secretory pattern hold promise for improved methods to diagnose LPD in the future.

The effect of deliberate omission of Trinordiol or Microgynon on the hypothalamo-pituitary-ovarian axis

The effect of deliberate omission of a phased formulation pill, Trinordiol (ethinyl estradiol 30 micrograms + levonorgestrel 50 micrograms: 6 tablets; ethinyl estradiol 40 micrograms + levonorgestrel 75 micrograms: 5 tablets; ethinyl estradiol 30 micrograms + levonorgestrel 125 micrograms: 10 tablets) or a low-dose, combined, oral contraceptive pill, Microgynon (ethinyl estradiol 30 micrograms + levonorgestrel 150 micrograms: 21 tablets) on the hypothalamo-pituitary-ovarian axis were studied. Thirty-six women were recruited to the study and divided equally between the two types of pill. Medication was begun on the 8th pill-free day of the cycle and continued for 7 days (Group 1), 14 days (Group 2) or 21 days (Group 3). Levels of FSH, LH, estradiol (E2) and progesterone (P) were measured in plasma on alternate days during the final week of pill therapy, and daily for the 7 days after stopping the pill. For the first 2 weeks of pill therapy, follicular activity, as judged by plasma levels of E2, was greater in women taking Trinordiol than in those taking Microgynon, but was similar in both groups by the third week of pill treatment. Five women taking Trinordiol (2 in Group 1 and 3 in Group 2) had plasma levels of E2 in excess of 500 pmol/l whilst taking the pills, and only 1 patient achieved this degree of follicular activity after stopping the tablets. One woman who had taken 7 days of Trinordiol (Group 1) showed a rise of plasma levels of P to 6.8 nmol/l, but luteinization did not occur in any of the remaining 35 women who took Trinordiol or Microgynon. These findings suggest that follicular activity is less completely suppressed by Trinordiol than Microgynon, at least in the first 2 weeks of pill therapy, but that normal ovulation is still a rare event in the week after cessation of either of these pills, even if only 7 days of medication have been taken.