Effect of intraovarian platelet-rich plasma injection on IVF outcomes in women with poor ovarian response: the PROVA randomized controlled trial.

STUDY QUESTION: Does intraovarian platelet-rich plasma (PRP) injection increase the number of mature oocytes obtained after controlled ovarian stimulation (COS) in young women with poor ovarian response (POR) undergoing IVF? SUMMARY ANSWER: Intraovarian PRP injection procedure does not improve mature oocyte yield after COS in women less than 38 years old with an established IVF history of POR. WHAT IS KNOWN ALREADY: POR is frequently encountered among the infertile population and the number of women seeking infertility treatment related to POR is increasing. Effective treatment options for this patient population to conceive with autologous oocytes are lacking. Case series and cohort studies suggest that intraovarian PRP injection may improve follicular recruitment in women with premature ovarian insufficiency (POI) and POR, yet robust randomized studies have not been performed to date to determine the clinical utility of this intervention. STUDY DESIGN, SIZE, DURATION: This was a multi-center randomized controlled trial (RCT) conducted at university-affiliated reproductive centers in the USA and Turkey, between January 2020 and November 2022. PARTICIPANTS/MATERIALS, SETTING, METHODS: Patients who met inclusion criteria (<38 years old, two or more prior cycles with <3 oocytes retrieved; and without single gene disorders, prior ovarian surgery, endometriomas, BMI >35 kg/m2, or severe male factor infertility) were randomized to either the PRP or control group. Patients in both groups subsequently underwent COS, oocyte retrieval, ICSI, preimplantation genetic testing for aneuploidy (PGT-A), and single euploid embryo transfer. Number of metaphase II (MII) oocytes obtained was the primary outcome. Secondary outcomes included ovarian reserve tests (antral follicle count [AFC] and anti-Müllerian hormone [AMH]), blastocyst and euploid blastocyst yields, and sustained implantation. The study was powered to detect a difference of one mature oocyte obtained at oocyte retrieval. MAIN RESULTS AND THE ROLE OF CHANCE: In total, 83 patients met inclusion criteria and were randomized to receive autologous intraovarian PRP injection (n = 41) or to no intervention (n = 42). No significant differences were observed in number of MII oocytes retrieved per cycle (2.8 ± 2.4 vs 3.1 ± 3.3 in PRP vs control, respectively; P = 0.9), blastocysts (1.0 ± 1.3 vs 1.3 ± 2.1, P = 0.8), or euploid blastocysts (0.8 ± 1.1 vs 0.9 ± 1.6; P = 0.5). Similarly, no differences were observed in the likelihood of obtaining at least one euploid blastocyst (45% vs 37%, P = 0.4; relative risk [RR], 95% CI = 0.9, 0.6-1.2) or the rate of sustained implantation (31% vs 29%, P = 0.9; RR 1.0, 0.7-1.3). Posttreatment AFC (7.9 ± 4.5 vs 6.8 ± 4.8, P = 0.3) and AMH (0.99 ± 0.98 vs 0.7 ± 0.6, P = 0.2) were also not different between the groups. LIMITATIONS, REASONS FOR CAUTION: Results from this RCT may not be generalizable to other PRP preparations owing to heterogeneity and lack of standardization. The control groups did not undergo a sham ovarian injection, which would have been relevant had the results shown benefit of PRP injection. Only patients with POR were included in this study, and these results may not be generalizable to more severe diminution of ovarian reserve, as seen with POI. WIDER IMPLICATIONS OF THE FINDINGS: The intraovarian PRP injection procedure does not improve mature oocyte yield or other parameters of IVF outcome in women less than 38 years old with an established IVF history of POR. The results from this study do not support the use of intraovarian PRP injection in this population. STUDY FUNDING/COMPETING INTEREST(S): Departmental funds were used and no external funding was requested for this study. ES is a consultant for and receives grant funding from the Foundation for Embryonic Competence. All other authors have no conflict of interest to declare. TRIAL REGISTRATION NUMBER: Clinicaltrials.gov Registry Identifier: NCT04163640. TRIAL REGISTRATION DATE: 15 November 2019. DATE OF FIRST PATIENT'S ENROLMENT: 24 February 2020.

Digestibility and nutritional value of fresh and stored pollen for honey bees (Apis mellifera scutellata).

Pollen, the main protein source for honey bees, is mixed with regurgitated nectar or honey during collection and then stored as 'bee bread' before its consumption, mainly by young nurse workers. It has been suggested that storage of pollen improves its nutritional value and digestibility, but there is little evidence for such changes. We fed two fresh pollen types of different protein content (aloe and sunflower), and two stored pollen types (sunflower and a mixed pollen), to young caged worker bees. We measured daily consumption of pollen and sucrose solution, and survival after 14 days. At day 14 we recorded ovarian activation and extraction efficiency, by counting empty pollen grains in the rectal contents. Extraction efficiency is a measure of pollen digestibility. Contrary to our predictions, bees did not consume more fresh sunflower pollen than fresh aloe pollen to compensate for the lower protein content of sunflower pollen. In addition, they did not consume less sucrose solution when fed stored pollen diets that are already enriched in sugar. Consumption of stored sunflower pollen resulted in a low protein to carbohydrate (P:C) intake. Survival and ovarian activation were higher on diets giving higher P:C intakes. Extraction efficiency was high (up to 99%) for all pollen diets, and comparison of fresh and stored sunflower pollen showed that storage did not make it easier to digest. Changes to pollen during storage do not confer obvious benefits to honey bees.

Effects of age and Reproductive Status on Tergal Gland Secretions in Queenless Honey bee Workers, Apis mellifera scutellata and A. m. capensis.

Secretions from tergal glands are part of a queen's pheromonal control of worker reproduction in honey bees. However, in queenless honey bee colonies, workers compete to gain pheromonal, and hence reproductive dominance, over nestmates with ontogenetic changes in their glandular secretions that affect the behavioral or physiological responses of other individuals. Using gas chromatography/mass spectrometry, we investigated for the first time the age-dependent changes in tergal gland secretions of queenless workers of the clonal lineage of Apis mellifera capensis and workers of A. m. scutellata. The reproductive status of honey bee workers was determined by recording the presence of spermathecae and the level of ovarian activation. The tergal gland chemicals identified in both A. m. scutellata workers and A. m. capensis clone workers were oleic acid, n-tricosene, n-pentacosene, and n-heptacosene, with three additional compounds, palmitic acid, n-heneicosene, and n-nonacosene, in A. m. capensis clones. We report ethyl esters as new compounds from honey bee worker tergal gland profiles; these compounds increased in amount with age. All A. m. capensis clone workers dissected had spermathecae and showed ovarian activation from day 4, while ovarian activation only started on day 7 for A. m. scutellata workers that had no spermathecae. Tergal gland secretions were present in higher quantities in bees with activated, rather than inactive ovaries. This suggests that tergal gland secretions from reproductive workers could act as releaser and primer pheromones in synergy with other glandular compounds to achieve pheromonal and reproductive dominance.