Thawing fertility: A View of Ovarian Tissue Cryopreservation Processes and Review of Ovarian Transplant Research.

Individuals with a disease or treatment that will increase their risk of premature gonadal insufficiency may opt to undergo fertility preservation. Those who are post-pubertal can often cryopreserve gametes, sperm or eggs, to expand their biological family using assisted reproductive technologies. Ovarian tissue cryopreservation (OTC) and testicular tissue cryopreservation may be an option for individuals who are unable to utilize standard fertility preservation techniques. The development of OTC was critical for many patients, including prepubertal children with ovaries that do not yet produce eggs, adolescents who make few good quality eggs and adult women with ovaries who cannot undergo ovarian stimulation. The only option to restore fertility and hormone production following OTC is through ovarian tissue transplantation (OTT). OTC and OTT have been successful for some patients. While OTC is no longer considered experimental by the American Society of Reproductive Medicine, the process is far from standardized. Significant research needs to be done, especially at the point of OTT, to improve the success and longevity of the ovarian tissue function. This article lists the main steps from surgical procurement of the ovarian tissue to transplantation and restoration of function. Our pediatric hospital program has had to decide which options in procurement, processing, cryopreservation and warming will be used in our clinical lab. The options and limitations within the research and analyses are briefly discussed. Literature focusing on techniques to improve OTT effectiveness and longevity was reviewed. OTT studies that performed xenograft experiments after pretreatment of the tissue graft by a ligand or drug, treatment of host, or encapsulation of the ovarian tissue were identified. The intended effects of the treatments include increasing vascularization, reducing apoptosis and directing activation or suppression of primordial follicles. Robust research in this area must continue with rigorous analyses to make strides for improving fertility preservation and restoration options for patients.

Correlation of Renal Tissue Oxygenation to Venous, Arterial, and Capillary Blood Gas Oxygen Saturation in Preterm Neonates.

OBJECTIVE: The aim of the study is to assess the correlation of renal regional tissue saturation of oxygen (RrSO2) measured by near-infrared spectroscopy (NIRS) in preterm neonates to venous oxygen saturation (SvO2) obtained from umbilical venous catheters (UVCs), arterial oxygen saturation (SaO2) obtained from umbilical artery catheters (UACs), and capillary oxygen saturation (ScO2) from capillary heel blood draws. STUDY DESIGN: A secondary analysis of a prospective RrSO2 monitoring study in preterm neonates born <32 weeks gestational age. Neonates with any blood gas obtained during RrSO2 monitoring were included. RrSO2 was compared with simultaneous O2 saturation using non-parametric Mann Whitney U-test and Spearman correlation coefficient. RESULTS: In 35 neonates, 25 UVC, 151 UAC, and 68 heel capillary specimens were obtained. RrSO2 was lower than the median SvO2 (58.8 vs. 78.9, p <0.01), SaO2 (51.0 vs. 93.2, p <0.01), and ScO2 (62.2 vs. 94.25, p <0.01). RrSO2 values correlated to both SaO2 and ScO2 (r = 0.32; p <0.01, r = 0.26; p = 0.03), but not SvO2 (r = 0.07; p = 0.74). CONCLUSION: In this secondary analysis, RrSO2 was consistently lower than blood gas O2 saturations and correlated with SaO2 and ScO2 but not SvO2. Lack of a correlation to SvO2 could be due to the small UVC sample size limiting statistical power. Future studies should prospectively evaluate if RrSO2 truly primarily reflects venous oxygenation in preterm neonates. KEY POINTS: · Renal oxygenation correlates with arterial and capillary oxygen saturation.. · Renal oxygenation did not correlate with venous oxygenation from umbilical venous catheters.. · Studies are needed to determine if renal oxygenation primarily reflects venous or arterial oxygen..

Gender analysis of Journal of Perinatology authorship during COVID-19.

OBJECTIVE: To examine authorship gender distributions before and during COVID-19 in the Journal of Perinatology. STUDY DESIGN: We collected data from the Journal of Perinatology website. The author gender was determined using Genderize.io or a systematic internet search. Our primary outcome was the difference between the number of published articles authored by women during the pandemic period (March 2020-May 2021, period two), compared with the preceding 15-month period (period one). We analyzed the data using chi-square tests. RESULTS: Publications increased from period one to two by 8.9%. There were slightly more female than male first (62%) and overall (53%) authors, but fewer last authors (43%) for the combined time periods. Female authorship distribution was not different between periods. CONCLUSIONS: Though publications increased overall, authorship gender distribution did not change significantly during the COVID-19 pandemic. Women authors remain underrepresented overall and specifically as last author, considering the majority of neonatologists are women.