The Ratio of Serum Progesterone (P4) to the Number of Follicles (P4/follicle) is a More Objective Parameter for Euploidy Rate as Compared to Systemic Progesterone Levels

Does the late follicular phase progesterone (P4) and the P4-to-follicle-ratio affect the ploidy state of the biopsied embryos? A retrospective observational study conducted at ART Fertility Clinics Abu Dhabi and Muscat, including all stimulation cycles performed between January 2015 and December 2019. In total, 975 cycles were considered for this study. Inclusion criteria were ovarian stimulation due to primary/secondary infertility, patient's age between 18 and 45 years, ICSI as fertilization method, and patients undergoing preimplantation genetic testing for aneuploidies (PGT-A). Patients with testicular sperm extraction (TESE) and warmed oocytes were excluded. Our results have shown that progesterone had no effect on the euploid rate (p = 0.371). However, when adding the ratio of P4 to the number of follicles that were bigger than 10 mm in the last scan, a negative effect on the euploid rate (p < 0.05) was observed. This study was able to show that the use of only P4 is unable to predict ploidy outcomes. However, by including the number of follicles > 10 mm, a clear association was observed between P4/Foll ratio and euploid rate per cycle. The use of both parameters could aid clinicians in their decision to trigger a patient or continue stimulation. Further prospective studies are warranted to confirm those results.

Exogenous progesterone-dependent modulation in the follicular dynamics of Bos indicus cattle undergoing repeated ovum pick-up sessions

The objective of the present study was to evaluate the role of serum progesterone (P4) in follicular dynamics, oocytes' recovery and quality and their in vitro developmental competence during consecutive ovum pick-up (OPU) sessions in Bos indicus dairy cows. Wave-synchronized Sahiwal cattle (n = 20) were randomly divided into treatment (n = 10) and control (n = 10) groups. CIDR was used as a source of external progesterone in the treatment group. Four consecutive OPU sessions at 96-hr intervals were conducted and repeated ultrasonography at 12-hr intervals was done to monitor follicular dynamics. The viable oocytes were processed for IVC following IVM and IVF until day 7. The serum P4 concentrations in the P4 and control groups were recorded as 2.31 ± 0.059 versus.0.32 ± 0.065 ng/ml, respectively (p < .05). In the treatment group, the total number of recorded follicles was higher (p < .05; 12.05 ± 0.37 versus. 10.87 ± 0.40), whilst the growth rate (mm/day) of follicles was lower (p > .05). Per session recovered oocytes (5.31 ± 0.19 versus. 3.58 ± 0.21; p < .0001) and recovery rate (54.23 versus. 42.53%; p < .05) were also higher in the treatment group compared to control. Similarly, the viable oocytes (4.54 ± 0.187 versus. 3.06 ± 0.199) and the number of grade I and II oocytes per session (3.37 ± 0.196 versus. 2.06 ± 0.21) were higher (p < .05) in the treatment group compared with the control group. However, the nuclear maturation, cleavage, and blastocyst rate did not differ (p > .05) between the groups. Taken together, during OPU sessions, serum P4 improves oocytes' recovery and quality, whilst does not affect the in vitro developmental competence of recovered oocytes.

Ghrelin antagonist D-Lys3-GHRP-6 counteract ghrelin effects in bovine cumulus-oocytes complexes matured in vitro

Ghrelin is a gut hormone related to energy balance and reproductive functions. The aim of this study was to evaluate the effect of ghrelin antagonist D-Lys3-GHRP-6 (GA) as a potential agent that prevents ghrelin effects during bovine oocyte maturation on progesterone production, cumulus cell (CC) viability, CC DNA damage and embryo development and hatching rates. Ghrelin's potential to induce oxidative stress in cumulus-oocyte complexes (COC) was also evaluated. COCs were cultured for 24 hr in medium without supplementation (C) or supplemented with 60 pM ghrelin (Ghrelin60), Ghrelin60 + 20 pM GA (GA20), Ghrelin60 + 60 pM GA (GA60) or Ghrelin60 + 100 pM GA (GA100) for experiment I. For experiment II, C and Ghrelin60 treatments were used. Differences between C and Ghrelin60 and the linear or quadratic association between GAs on Ghrelin60 were evaluated. Results demonstrated that Ghrelin60 increased progesterone concentration, reduced CC viability, induced CC DNA damage and decreased blastocyst and hatching rate compared with C (p < .05). GA20, GA60 and GA100 had a linear effect on CC genetic damage index (p ≤ .05) and a quadratic effect on CC viability (p < .01). GA20 counteracted the low hatching rate produced by Ghrelin60. However, GAs did not counteract progesterone concentration and blastocyst rate (p ≥ .21). GRH60 did not differ from C in the oxidative status (p ≥ .19). Our study highlights that GA could prevent the negative effects of ghrelin during bovine IVM.

Effect of dose and timing of prostaglandin F2α treatments during a 7-d Ovsynch protocol on progesterone concentration at the end of the protocol and pregnancy outcomes in lactating Holstein cows

The objective of this study was to evaluate the effect of two prostaglandin F_2α (PGF) treatments 24 h apart (500 μg of cloprostenol) and treatment with a double PGF dose on d 7 (1000 μg of cloprostenol) during a 7-d Ovsynch protocol on progesterone (P4) concentration and pregnancy per artificial insemination (P/AI) in lactating Holstein cows. We hypothesized that treatment leads to a decreased P4 concentration at the second GnRH treatment (G2) and an increase in P/AI compared to the traditional 7-d Ovsynch protocol. A secondary hypothesis was that the treatment effect is influenced by the presence of a corpus luteum (CL) at the first GnRH treatment (G1). Two experiments were conducted on 8 commercial dairy farms in Germany. Once a week, cows from both experiments were assigned in a consecutive manner to receive: (1) Ovsynch (control: GnRH; 7 d, PGF; 9 d, GnRH), (2) Ovsynch with a double PGF dose (GDPG: GnRH; 7 d, 2xPGF; 9 d, GnRH), or (3) Ovsynch with a second PGF treatment 24 h later (GPPG: GnRH; 7 d, PGF; 8 d, PGF; 32 h, GnRH). All cows received timed AI (TAI) approximately 16 h after G2. Pregnancy diagnosis was performed by transrectal palpation (38 ± 3 d after TAI, experiment 1) or transrectal ultrasonography (35 ± 7 d after TAI, experiment 2). Whereas farms from experiment 1 used a Presynch-Ovsynch protocol (PGF, 14 d later PGF, 12 d later GnRH, 7 d later PGF, 2 d later GnRH, and 16-18 h later TAI) to facilitate first postpartum TAI, no presynchronization protocol was used on farms from experiment 2. In experiment 1, we enrolled 1581 lactating dairy cows (60 experimental units) from 2 dairy farms. At G2, blood samples were collected from a subsample of cows (n = 491; 16 experimental units) to determine P4 concentration at G2. In experiment 2, we enrolled 1979 lactating dairy cows (252 experimental units) from 6 dairy farms. Transrectal ultrasonography was performed to determine the presence or absence of a CL at G1. In experiment 1, treatment affected P/AI (P = 0.01) and P/AI was greater for GDPG (38.2%) and GPPG (38.9%) than for control cows (29.8%). Both, GDPG and GPPG cows had decreased P4 concentration at G2 compared with control cows (P < 0.01). Whereas both treatments increased the percentage of cows with very low P4 concentration (0.00-0.09 ng/mL) at G2, only the GPPG treatment decreased the percentage of cows with high P4 concentration (≥0.6 ng/mL) at G2 compared to the control group. In experiment 2, P/AI was greater for GPPG (37.4%) than for control cows (31.0%; P = 0.03) and tended to be greater than for GDPG cows (31.8%; P = 0.05). Cows from the GDPG group had similar (P = 0.77) P/AI compared to the control group. Pregnancy per AI did not differ between cows with a CL at G1 and cows without a CL at G1 (34.1% vs. 32.6%; P = 0.50). There was no interaction between treatment and presence of a CL at G1 on P/AI (P = 0.61). Combining data from the 2 experiments but excluding cows from experiment 1 receiving presynchronization before first TAI (n = 2573; 312 experimental units), P/AI was greater for GPPG (40.3%; P < 0.01) than for control (31.8%) and GDPG cows (33.4%). Between GDPG and control cows, P/AI did not differ (P = 0.46). We conclude that overall the addition of a second PGF treatment on d 8 during a 7-d Ovsynch protocol increased P/AI compared to the traditional 7-d Ovsynch including a single PGF dose on d 7 and to a double PGF dose on d 7. Doubling the PGF dose on d 7 in a 7-d Ovsynch protocol did not affect P/AI. Use of a presynchronization protocol, however, seems to influence the effect of a dose frequency modification of PGF treatment in an Ovsynch protocol. Presynchronized cows receiving first postpartum TAI had similarly increased P/AI treated with a double PGF dose compared with treatment with a second PGF dose. Future studies need to elucidate whether the treatment effect is modified by presynchronization of the first postpartum TAI.

Corpora lutea affect in vitro maturation of bovine cumulus-oocyte complexes and embryonic development after fertilization with sex-sorted or conventional semen

Influence of both the presence of a corpus luteum on the ovary and semen sex-sorting on development following in vitro fertilization is not yet conclusive. To determine the effect of these factors, 376 bovine oocytes were processed in vitro according to luteal presence on the ovary (CL+ and CL-) and type of semen used (sexed or conventional). Maturation rate was higher (P < 0.01) in CL- (136/138; 98.6%) than in CL+ (217/238; 91.2%). Cleavage rate was lower (P < 0.01) in CL+ with sexed semen (60/172; 34.9%) than in CL- with sexed semen (42/71; 59.1%), CL+ with conventional semen (47/66; 71.2%), and CL- with conventional semen (54/67; 85.1%). Compaction was similar (P = 0.69) in CL- (49/99; 49.4%) and CL+ (50/107; 46.7%). Blastulation rate was higher (P < 0.01) in CL- (26/99, 26.2%) than in CL+ (13/107; 12.1%) group. Expansion rate was higher (P = 0.01) in CL- (22/99; 22%) than in CL+ (11/107; 10.2%) group. Compaction rates were similar (P = 0.78) in sex-sorted (50/102; 49.0%) or conventional semen (49/104; 47.1%) groups. Blastulation was also similar (P = 0.91) with sex-sorted semen (19/102; 18.6%) and conventional semen (20/104; 19.2%). The rate of expanded blastocysts was similar (P = 0.89) in sex-sorted (16/102; 15.6%) and conventional (17/104; 16.3%) semen groups. In conclusion, the presence of CL can compromise maturation of the oocytes and their development, as a higher proportion of cleavage-stage embryos can be obtained with non-sexed semen with oocytes from ovaries without a CL.

The use of adenosine to inhibit oocyte meiotic resumption in Bos taurus during pre-IVM and its potential to improve oocyte competence

One of the major challenges of artificial reproductive technologies is to develop new methods for producing greater numbers of embryos. An oocyte fosters the ability to develop into an embryo before oocyte meiotic resumption. The aim of the present study was to assess the effect of adenosine (ADO), a purine nucleoside found in follicular fluid, on the inhibition of oocyte meiotic resumption and the production of blastocysts. The results showed the efficacy of ADO to inhibit oocyte meiotic resumption. The use of ADO (3 mM) during a pre-in vitro maturation (pre-IVM) culture period of 6 h resulted in a significant increase (p < 0.05) of blastocysts compared to control conditions with no pre-IVM culture period. No effect on the percentage of cleavage was observed. The effect of adenosine on blastocyst yield was time- and concentration-dependent with an optimum effect at 3 mM for 6 h. Supplementing the ADO pre-IVM culture medium with estradiol, follicle-stimulating hormone, progesterone, epidermal growth factor, insulin-like growth factor-2 or reelin did not improve the blastocyst yield. Transcriptional analyses of ADO-treated cumulus cells revealed that NRP1, RELN, MAN1A1, THRA and GATM were up-regulated. Finally, bioinformatic analysis identified mitochondrial function as the top canonical pathway affected by ADO. This opens up new opportunities for further investigations.

Three-step in vitro maturation culture of bovine oocytes imitating temporal changes of estradiol-17<i>β</i> and progesterone concentrations in preovulatory follicular fluid

Abstract. The objective of the article is to evaluate the effect of three-step in vitro maturation (IVM) culture system imitating estradiol-17β (E2) and progesterone (P4) concentrations in preovulatory follicles on in vitro bovine embryo production. The cumulus–oocyte complexes (COCs) were collected from follicles (2 to 8 mm in diameter) of bovine ovaries obtained from a local slaughterhouse. For IVM, the COCs were cultured for 22 h in a three-step system: (1) culture in medium 199, containing 700 ng mL−1 E2 and 50 ng mL−1 P4, for 5 h, followed by the medium containing 150 ng mL−1 E2 and 150 ng mL−1 P4 for 11 h, and then the medium containing 20 ng mL−1 E2 and 300 ng mL−1 P4 for 6 h (EP group); (2) culture in the medium containing 700 ng mL−1 E2 for 5 h, followed by the medium containing 150 ng mL−1 E2 for 11 h, and then the medium containing 20 ng mL−1 E2 for 6 h (E group); or (3) culture in the medium containing 50 ng mL−1 P4 for 5 h, followed by the medium containing 150 ng mL−1 P4 for 11 h, and then the medium containing 300 ng mL−1 P4 for 6 h (P group). The COCs were cultured in the medium containing 1000 ng mL−1 E2 for 22 h (control group). After IVM, the COCs were co-incubated with sperm and further cultured. At 48 h after insemination, the cleavage rate of embryos was not different among the groups. At 192 h after insemination, the blastocyst formation rate of EP group was significantly higher than that of the other groups. The total cell number of blastocysts did not differ among the groups. In conclusion, these results demonstrate that the three-step IVM culture system of bovine oocytes imitating temporal changes of E2 and P4 concentrations in preovulatory follicular fluid improves the developmental potential of embryos in vitro.

Neonatal outcomes and congenital malformations in children born after human menopausal gonadotropin and medroxyprogesterone acetate treatment cycles

PURPOSE

To investigate neonatal outcomes and congenital malformations in children born after in vitro fertilization (IVF) and vitrified embryo transfer cycles using human menopausal gonadotrophin and medroxyprogesterone acetate (hMG + MPA) treatment.

METHODS

We performed a retrospective cohort study including 4596 live born babies. During January 2014-June 2016, children born after either hMG + MPA treatment, gonadotropin releasing hormone agonist short protocol, or mild ovarian stimulation were included. The main outcome measures were neonatal outcomes and congenital malformations.

RESULTS

Neonatal outcomes both for singletons and twins such as mean birth weight and length, gestational age, the frequency of preterm birth were comparable between groups. Rate of stillbirth and perinatal death were also similar. No significant differences were found in the overall incidence of congenital malformations between the three groups. Multivariable logistic regression indicated that hMG + MPA regimen did not significantly increase the risk of congenital malformations compared with short protocol and mild ovarian stimulation, with adjusted odds ratio of 1.22 [95% confidence interval (CI) 0.61-2.44] and 1.38 (CI 0.65-2.93), respectively, after adjusting for confounding factors.

CONCLUSIONS

Our data suggested that compared with conventional ovarian stimulations, hMG + MPA treatment neither compromised neonatal outcomes of IVF newborns, nor did increase the prevalence of congenital malformations.

Heat stress effects on the cumulus cells surrounding the bovine oocyte during maturation: altered matrix metallopeptidase 9 and progesterone production

When the effects of heat stress are detrimental during maturation, cumulus cells are intimately associated with the oocyte. To determine the extent to which heat stress affects these cells, in this study, transcriptome profiles of the cumulus that surrounded control and heat-stressed oocytes (41 °C during the first 12 h only and then shifted back to 38.5 °C) duringin vitromaturation (IVM) were compared using Affymetrix bovine microarrays. The comparison of cumulus-derived profiles revealed a number of transcripts whose levels were increased (n=11) or decreased (n=13) ≥ twofold after heat stress exposure (P<0.01), sufficient to reduce the development of blastocysts by 46.4%. In a separate study, quantitative PCR (qPCR) was used to confirm heat-induced differences in the relative abundances of the transcripts of five different genes (caveolin 1, matrix metallopeptidase 9, FSH receptor, Indian hedgehog homolog, and inducible nitric oxide synthase). Heat stress exposure resulted in >1.7-fold decrease in the protein levels of latent matrix metallopeptidase 9 (proMMP9). Heat-induced reductions in transcript levels were noted at 6 h IVM with reductions in proMMP9 protein levels at 18 h IVM (P=0.0002). Independent of temperature, proMMP9 levels at 24 h IVM were positively correlated with the development rate of blastocysts (R2=0.36;P=0.002). The production of progesterone increased during maturation; heat-induced increases were evident by 12 h IVM (P=0.002). Both MMP9 and progesterone are associated with the developmental competence of the oocyte; thus, it seems plausible for some of the negative consequences of heat stress on the cumulus–oocyte complex to be mediated through heat-induced perturbations occurring in the surrounding cumulus.

The effects of substituting glassware for plasticware and the use of an ethanol vector on oocyte maturation in vitro

The intent of this study was to evaluate specific technical aspects of in vitro oocyte maturation (IVM), which included container material and solvent delivery vector. Oocytes were matured in oil-free, open-well systems contained in either plastic or glass dishes and compared to control oocytes matured in media droplets on plastic dishes overlaid with mineral oil. Open-well experiments were repeated with ethanol in a quantity sufficient for delivery of nonmiscible compounds. Cleavage rates were significantly decreased in the glassware system when compared to controls. The plasticware open-well system did not differ from either the controls or the glassware groups. Cleavage in glassware with ethanol was significantly lower than controls or plasticware with ethanol. Blastocyst rates were only decreased in the glassware-ethanol treatment when compared to plasticware-ethanol treatment. Cell counts and percentage of TUNEL-positive cells did not differ significantly. Unexpectedly, sex ratio was significantly decreased (34% male) from the expected value of 50% male in the glassware group with added ethanol. The current study demonstrates the sensitivity of IVM to subtle technical changes, resulting in significant developmental consequences.

Evidence that high variation in antral follicle count during follicular waves is linked to alterations in ovarian androgen production in cattle

Androgens have an important role in ovarian follicular growth and function, but circulating androgen concentrations are also associated with ovarian dysfunction, cardiovascular disease, and metabolic disorders in women. The extent and causes of the variation in androgen production in individuals, however, are unknown. Because thecal cells of follicles synthesize androstenedione and testosterone, variation in production of these androgens is hypothesized to be directly related to the inherently high variation in number of healthy growing follicles in ovaries of individuals. To test this hypothesis, we determined whether thecal CYP17A1 mRNA (codes for a cytochrome P450 enzyme involved in androgen synthesis), LH-induced thecal androstenedione production, androstenedione concentrations in follicular fluid, and circulating testosterone concentrations were lower in cattle with relatively low versus high number of follicles growing during follicular waves and whether ovariectomy reduced serum testosterone concentrations. Results demonstrated that cattle with a low follicle number had lower (P<0.05) abundance of CYP17A1 mRNA in thecal cells, reduced (P<0.01) capacity of thecal cells to produce androstenedione in response to LH, lower (P<0.01) androstenedione concentrations in ovulatory follicles, and lower (P<0.02) circulating testosterone concentrations during estrous cycles compared with animals with high follicle number. Also, serum testosterone in cattle with low or high follicle number was reduced by 63 and 70%, respectively, following ovariectomy. In conclusion, circulating androgen concentrations are lower in cattle with low versus high number of follicles growing during follicular waves, possibly because of a reduced responsiveness of thecal cells to LH.

Offspring produced from heterotopic ovarian allografts in male and female recipient mice

Studies on human ovarian xenografts and mouse allografts indicate that the male hormonal milieu and exogenous gonadotrophin administration stimulate antral follicle growth. However, it is not known whether oocytes produced under these conditions are developmentally competent. The objective of our study was to evaluate the developmental competence of oocytes produced in heterotopic mouse ovarian grafts placed in male and female recipient mice. Gonadotrophins were 7.5 IU pregnant mare serum gonadotrophin (PMSG) alone or 7.5 IU PMSG and 7.5 IU human chorionic gonadotrophin or were not given prior to oocyte collection. The developmental competence of oocytes was assessed by performing in vitro fertilisation and embryo transfer to recipients. When no gonadotrophins were given the cleavage rate was similar for oocytes collected from ovarian grafts in male and female recipients. Gonadotrophin treatment significantly (P < 0.05) increased two-cell formation by oocytes grown in female graft recipients but not in male recipients. Implantation rates, fetal development and the birth of live young were unaffected by the sex of the graft recipient or gonadotrophin treatment. Live offspring were produced from oocytes collected from ovarian grafts in male and female recipients treated with or without gonadotrophins. In conclusion, this work has shown that the hormonal environment of male mice can support the growth of oocytes in ovarian allografts and that these oocytes can produce live offspring.

Patient scheduling for gonadotrophin-releasing hormone antagonist protocols

Gonadotrophin-releasing hormone (GnRH) antagonists offer an alternative approach to the management of superovulation in assisted conception. Although several large multicentre randomized trials have provided information concerning the safety and efficacy of GnRH antagonists, their introduction into clinical practice has identified several new problems and opportunities. In vitro fertilization (IVF) practitioners with many years of experience of the 'long protocol' of pituitary downregulation with GnRH agonists have had to manage unfamiliar problems associated with patient scheduling and IVF cycle management when introducing GnRH antagonists into practice. Antagonist cycles require greater flexibility on the part of the IVF unit, with a need for 6 (or even 7) day working patterns and altered monitoring schedules. This article addresses the possibility of using oral contraceptives as part of GnRH antagonist cycle programming, and examines the definition of a 'good' cycle when using the antagonist.