Characterization of sperm cell membrane charge and selection of high-quality sperm using microfluidics in stallions.

Intracytoplasmic sperm injection (ICSI) is the only method for in vitro embryo production (IVP) in horses. Besides oocyte developmental competence, the outcome of IVP is also highly dependent on sperm quality. Therefore, it is not only essential to employ superior methods of selecting high quality sperm, but also to be able to characterize which quantifiable properties of sperm quality are most indicative of its fertility. In men, a net negative surface charge, estimated by zeta potential (ZP) is highly correlated with sperm quality and in vitro embryo developmental outcomes. However, there is no information available about approximate charges or ZP in equine sperm. Therefore, in this study we aimed to characterize equine sperm ZP and identify its associations with known measures of sperm quality. Additionally, we aimed to complete a comprehensive comparison of conventional sperm selection techniques as compared to the novel method of microfluidic sorting. Ejaculates (n = 22) were partitioned into fresh (∼23 °C, 0 h; n = 12) and cooled (∼4 °C, 24 h; n = 10) groups, and processed by swim up (SU), density gradient centrifugation (DGC), density gradient-swim up combination (DG-SU), and microfluidic chip (MF) sorting. Motility, progressive motility, cell viability, normal morphology, and ZP were evaluated for both unprocessed fractions and post-selected fractions. The ZP of both fresh and cooled samples was net negative and also correlated with motility and progressive motility for both fresh and cooled samples (P < 0.05). The ZP of cooled samples was also correlated with viability (P < 0.05). Among the compared methods of sperm selection, MF was highly effective in selecting high quality sperm as determined by the measured parameters. Percent motility, progressive motility, normal morphology, and viability of MF selected sperm were of higher quality than sperm selected by SU, and of similar to DG-SU and DGC without the use of potentially harmful centrifugation steps. Correlations between ZP, motility, and viability parameters may indicate a role of external charge on the motility and survival of sperm within the female reproductive tract. In conclusion, we identified an average net negative ZP on equine sperm and correlations between ZP and other measures of sperm quality, as well as having identified MF as a novel effective method of equine sperm selection for IVP.

Breastfeeding Motivators and Barriers in Women Receiving Medications for Opioid Use Disorder.

Background: Women with opioid use disorder (OUD) are encouraged to breastfeed, but have lower breastfeeding rates than the general population. Objective: We examined self-reported barriers and motivators for breastfeeding in women with OUD and the relationship between maternal/postnatal factors and breastfeeding noninitiation/discontinuation. Materials and Methods: A cross-sectional design was used; 40 women with OUD who were eligible to breastfeed were included. Information about breastfeeding initiation, duration, barriers/motivators, demographic characteristics, and self-efficacy was obtained through semi-structured interviews at 4-8 weeks postpartum. Wilcoxon rank sum or Fisher's exact test was used to examine the relationship between maternal/postnatal factors and never-initiated/discontinued breastfeeding. Results: Respondents were 29.3 ± 5.3 years old; most were prescribed buprenorphine (77.5%); and 36.8% of infants were treated for neonatal opioid withdrawal syndrome with methadone or morphine. Most (75.0%) participants initiated breastfeeding; 50.0% continued breastfeeding at 4-8 weeks. The most common motivators included infant health (100%) and bonding (45.0%). On average, women reported discontinuing breastfeeding at 3.3 ± 1.1 weeks postpartum. The most common barriers were concerns regarding transfer of medications or other substances to the infant (50.0%) and concerns about breast milk supply (35.0%). Mean self-efficacy scores were similar among those who continued versus never-initiated/discontinued breastfeeding (33.5 versus 33.0; p = 0.388). Neonatal intensive care unit admission was associated with never-initiated/discontinued breastfeeding (p = 0.047). Conclusion: Women with OUD share many similar motivators and barriers to breastfeeding with the general population. Unique concerns include infant exposure to medications or substances, even in those who are eligible to breastfeed, which should be addressed by targeted education for patients and providers.