Intensive FSH stimulation is a key tool of assisted reproduction technology but can cause severe complications through the development of an excessive number of small ovarian follicles. We tested the hypothesis that, in the late stages of ovulation induction, LH activity in the form of low-dose human CG (hCG) can stimulate and selectively modulate ovarian follicle function and growth, independently of FSH administration. Four groups of GnRH agonist-suppressed normoovulatory women (10 each group) received recombinant human FSH (r-hFSH) (150 IU/d) for 7 d followed by: group A, r-hFSH 150 IU/d alone; group B, r-hFSH 50 IU/d and hCG 50 IU/d; group C, r-hFSH 25 IU/d and hCG 100 IU/d; group D, hCG 200 IU/d alone. Despite several days of lowered or absent r-hFSH administration, 70% of hCG-treated patients successfully completed treatment. In these subjects, preovulatory E2 levels and large (>14 mm diameter) ovarian follicle development were not reduced; conversely, the number of small (<10 mm diameter) ovarian follicles was significantly decreased in groups B-D vs. group A. Low-dose hCG administration did not cause follicle luteinization. We conclude that, following FSH priming, LH activity administration can: 1) stimulate folliculogenesis for several days, in spite of rapidly declining FSH levels; and 2) hasten small follicle demise. Therefore, LH activity administration could be used to design radically novel ovulation induction regimens that, by partly or completely replacing mid-/late follicular phase FSH administration, may reduce costs and improve safety of assisted reproduction technology.
PMID 11889180 11889180 DOI 10.1210/jcem.87.3.8322 10.1210/jcem.87.3.8322 Filicori et al. 2002, Filicori 2002
Cite this article
Filicori, M., Cognigni, G. E., Tabarelli, C., Pocognoli, P., Taraborrelli, S., Spettoli, D., & Ciampaglia, W. (2002). Stimulation and growth of antral ovarian follicles by selective LH activity administration in women. The Journal of clinical endocrinology and metabolism, 87(3), 1156-1161. https://doi.org/10.1210/jcem.87.3.8322
Filicori M, Cognigni GE, Tabarelli C, Pocognoli P, Taraborrelli S, Spettoli D, et al. Stimulation and growth of antral ovarian follicles by selective LH activity administration in women. J Clin Endocrinol Metab. 2002;87(3):1156-1161. doi:10.1210/jcem.87.3.8322
Filicori, M., et al. "Stimulation and growth of antral ovarian follicles by selective LH activity administration in women." The Journal of clinical endocrinology and metabolism, vol. 87, no. 3, 2002, pp. 1156-1161.
To investigate the effects of letrozole in patients undergoing superovulation with gonadotropins and IUI. Retrospective analysis. Academic teaching hospital. PATIENT(S): Women younger than 40 years of age with patent fallopian tubes and infertility of more than 1 year in duration who were undergoing IUI and gonadotropin therapy. INTERVENTION(S): Gonadotropins alone administered from day 3 or a combination of letrozole, 5 mg/d on day 3 to 7, and gonadotropins starting on day 5 of the menstrual cycle. Ultrasonography was performed before initiation of treatment, on day 9 of menstrual cycle, and as required thereafter until the dominant follicle reached 18 mm in diameter. Ovulation was triggered with 10,000 IU of hCG, and IUI was performed 24 and 48 hours later. MAIN OUTCOME MEASURE(S): Gonadotropin requirements, endometrial thickness, number of follicles, and pregnancy rate. RESULT(S): All 205 IUI treatment cycles conducted from March 2001 to March 2002 were included. Gonadotropins alone were used in 145 cycles and combination therapy was used in 60 cycles. Patients cotreated with letrozole required fewer gonadotropin administrations (median difference, 300 IU [95% confidence interval (CI), 225-375 IU]), developed more follicles larger than 14 mm (median difference, 1 follicle [95% CI, 1-2 follicles), and had a thinner endometrium (median difference, 1 mm [95% CI, 0.4-1.6 mm]). The pregnancy rate did not differ between patients using gonadotropin alone and those using gonadotropin plus letrozole (20.9% vs. 21.6%). CONCLUSION(S): The addition of letrozole to gonadotropins decreases gonadotropin requirements, increases the number of pre-ovulatory follicles and decreases endometrial thickness, without a negative effect on pregnancy rates.
Malliou-Becher MN et al., 2026·Human reproduction (Oxford, England)
What are the variations in ovulation time and menstrual cycle characteristics among and within various individuals over the course of 12 menstrual cycles? There are considerable variations in both cycle length and ovulation time, with pronounced intra-individual variability over a 12-cycle observation period. Although it is commonly believed that healthy women have regular cycles with a predictable mid-cycle ovulation, more recent research shows a significant variation in cycle length and ovulation time. Previous studies have focused only on cycle length, often excluding cycles outside the 25-35-day range, thus limiting the understanding of natural variation; they have also lacked precise ovulation diagnostics or included small sample sizes, making it difficult to capture the full scope of cycle and ovulation variability. Similarly, a recent big data study, while valuable, was limited by a self-selected group and the absence of accurate ovulation diagnostics, reducing its generalizability. STUDY DESIGN, SIZE, This study was designed as a prospective long-term observational study, which involved collecting data from 1923 women with a total of 43 999 menstrual cycles from January 1985 to July 2019. After fulfilling the inclusion criteria, the main group consisted of 1051 women, all of whom contributed data for 12 cycles (12 612 cycles), including 420 conception cycles. PARTICIPANTS/MATERIALS, SETTING, Participants in the study were between 18 and 44 years of age at study entry and did not take any reproductive hormones. Women who were postpartum, breastfeeding, amenorrheic, or within a 3-month period after stopping hormonal contraception were excluded. Participants agreed to keep cycle records according to the symptothermal method, 'Sensiplan'. Ovulation time was determined using an evidence-based algorithm based on evaluating cervical mucus patterns and basal body temperature shifts, with ovulation time defined as the day before the temperature rise. Data analysis was descriptive, using absolute and relative frequencies, standard deviation, percentiles, and ranges. Age dependency was assessed using unpaired sample t-tests and one-way ANOVA. Linear regression was used to assess long-term trends. MAIN In 62.4% of women, cycle lengths varied by 1 week or more within 12 cycles. Accordingly, the time of ovulation varied by 1 week or more within 12 cycles in 54.8% of women, with 96.5% experiencing fluctuations of 4 days or more over the 12 months. The median spontaneous cycle length was 28 days, with a mean of 29.66 days (SD = 7.55). Only 52.7% of women consistently had cycle lengths between 23 and 35 days across all 12 cycles. Ovulation occurred most frequently between Days 12 and 16, with almost half of conceptions (45.7%) occurring after Day 16. A one-way analysis of variance revealed a significant reduction in mean cycle length with increasing age (P < 0.001), showing the shortest median cycle length of 27 days being in women aged 40-44 years. Age also impacted ovulation time, with women aged 35-39 years showing more stable ovulation patterns compared to younger women. Over the 34-year study period, average cycle length increased slightly but significantly (β = 0.0161, P = 0.0306), corresponding to approximately half a day. Intra-individual variability also showed a slight, but non-significant, upward trend (β = 0.0262, P = 0.2173). LIMITATIONS, Comorbidities such as hyperprolactinemia, obesity, and PCOS were not systematically excluded. However, by including only women with at least 12 cycles, the study largely avoided severe hormonal disorders. This study highlights the considerable individual variation of ovulation time and cycle length over 12 menstrual cycles. These findings contribute to a better understanding of fertility awareness, and highlight the implications for family planning and reproductive health management. STUDY FUNDING/COMPETING INTEREST(S): The authors declare no conflicts of interest. No funding was provided. N/A.
Traditionally, taste receptors (TRs) have been understood to reside within the taste buds on the tongue, serving as initiators for different taste perceptions. However, recent research has expanded our understanding, revealing that TRs are found throughout the body and perform a wide range of functions beyond taste perception as non-tasting functions. These receptors, along with their genetic variations, have been linked to various human health conditions. They are activated by an array of substances, including hormones, nutrients, and toxins, indicating their involvement in numerous biological processes. Specifically, in males, TRs are notably present in the testes and epididymis, where they contribute to the hormonal production, spermatogenesis, and sperm maturation. In females, these receptors are found in the ovaries, uterus, and myometrium, playing crucial roles in ovulation, menstrual cycle regulation, and embryo implantation. There are a lot of missed areas regarding TRs research that imposes to fulfill the gaps in the current understanding of their role in reproduction. This review aims to provide a comprehensive overview of the emerging roles of extraoral TRs in reproductive health, highlighting their physiological and pathophysiological significance in various reproductive processes. As well, grabbing the attention towards the release of new pharmacological interventions to manage conception and contraception in male and female was considered.
Arraztoa JA, 2025·J Restorative Reprod Med·
Open Access
In 1972, a seminal article was published demonstrating that women, adequately trained, could detect the approach of ovulation in the fertile window of their menstrual cycle. It was demonstrated that the symptoms perceived by women at the vulva correlate closely with changes in steroid hormone levels associated with folliculogenesis and the luteal phase. The fertility charting performed by women trained to recognize vulvar symptoms associated with hormonal changes serves as an instrument for detecting potential pathologies and monitoring the effects of treatment These findings established the biological foundations of a tool of fertility awareness tracking that has facilitated the development of restorative reproductive medicine (RRM): an approach that can be applied to identify and treat the underlying causes of infertility/subfertility.
Several core characteristics—or foundational pillars—of the RRM approach to fertility can be identified. These include: a commitment to respecting healthy physiological processes, comprehensive health care for both the couple and the potential embryo, and the provision of education and continuous support throughout the therapeutic process.
This commentary aims to elucidate the interplay of these foundational pillars by drawing upon evidence from peer-reviewed biomedical literature. Finally, the challenges faced by RRM in strengthening its scientific foundations, engaging with the broader scientific community, and promoting the dissemination of this approach are described.