Oocyte Retrieval in Asymptomatic Patients Positive for SARS-CoV-2.

Objective: To report two cases of oocyte retrieval performed in asymptomatic SARS-CoV-2-positive patients. Design: Case report. Setting. Outpatient private practice infertility center. Patients. A 28-year-old woman at risk for OHSS who took her trigger injection prior to testing positive for SARS-CoV-2 and a 19-year-old oncofertility patient who tested positive prior to retrieval due to a family exposure. Both patients were asymptomatic. Main Outcome Measures. Cycle outcomes, patient safety, and staff safety. Results: Both patients underwent successful oocyte retrieval procedures without developing symptoms or complications from COVID-19. No staff members that cared for these patients developed symptoms of COVID-19. Conclusion: Worsening fertility outcomes and potential for psychological and financial burdens to the patient must be balanced with risk of perioperative complications in patients testing positive for SARS-CoV-2. As we continue to provide fertility care in a world with COVID-19, appropriate risk mitigation strategies should be implemented to minimize exposure to SARS-CoV-2.

The promoter of the oocyte-specific gene, Gdf9, is active in population of cultured mouse embryonic stem cells with an oocyte-like phenotype.

The study of germ cell-specific gene regulation in vitro is challenging. Here we report that the promoter of the oocyte-specific gene, Gdf9, is active in a population of cultured murine embryonic stem cells (ES) which have a phenotype resembling oocytes. The promoter region of the murine Gdf9 coupled to enhanced green fluorescent protein (eGFP) was stably transfected into XX mouse ES cells. eGFP was expressed only in oocytes of chimeric mice generated from the transfected XX ES cells. The transfected ES cells were examined when cultured on feeder layers or as embryoid bodies. Large eGFP-positive cells, surrounded by a structure resembling a zona pellucida appeared transiently in cultures of the ES cells on feeder layers. Surprisingly, they were detectable on days 1 and 2 of culture but virtually absent on day 3. Addition of leukemia inhibitory factor (LIF) to the media significantly increased the number of eGFP-positive cels resembling oocytes. Quantitative-time PCR demonstrated a parallel increase in Gdf9 and Zp3 mRNA with changes in the abundance of eGFP-positive cells. In embryoid body cultures, eGFP-positive cells appeared transiently and then re-appeared in regional clusters after 30-45 days of culture. These findings demonstrate that a population of cultured murine ES cells contain the transcriptional machinery to drive expression of an oocyte-specific gene, and that those cells phenotypically resemble oocytes.

Middle to lower uterine segment embryo transfer improves implantation and pregnancy rates compared with fundal embryo transfer.

OBJECTIVE: To assess differences in pregnancy and implantation rates as a function of the embryo placement. DESIGN: Prospective cohort study. SETTING: A tertiary care center. SUBJECT(S): All fresh, nondonor IVF cycles performed in 2001. INTERVENTION(S): Alteration in embryo transfer (ET) target location from the fundal region to the middle to lower uterine segment. MAIN OUTCOME MEASURE(S): Clinical pregnancy rate (sonographic sac evidence/number of transfer cycles), implantation rate (number of sacs/number of embryos transferred), patient age, peak E(2), and fertilization rate. RESULT(S): A total of 393 fundal and 273 lower to middle uterine segment ETs were performed. The pregnancy (PR), implantation, and birth rates were significantly higher after a middle to lower uterine segment ET compared with fundal ET (39.6% vs. 31.2%; 21% vs. 14%; and 34.1% vs. 26.2%, respectively). Groups did not differ regarding patient age, basal FSH, peak E(2), number of intracytoplasmic sperm injection (ICSI) cycles, fertilization rate, embryo quality, or number of embryos transferred. CONCLUSION(S): Both PR and implantation rates are favorably affected by directing embryo placement to the lower to middle uterine segment. By some unknown mechanism, it appears that this endometrial location provides a more favorable region for embryo deposition.

The transfer point is a novel measure of embryo placement.

OBJECTIVE: To study the relationship between IVF-ET pregnancy outcomes and measures of embryo placement. DESIGN: Case-control study. SETTING: Tertiary care center. PATIENT(S): Twenty-three patients who underwent two ultrasonography-guided ETs, of which one resulted in a clinical pregnancy and the other did not. MAIN OUTCOME MEASURES: Point of embryo placement normalized to the endometrial cavity length (the transfer point), distance from the point of embryo placement to the uterine fundus, time required for ET, contact with the uterine fundus, and evidence of trauma. Videotaped ETs were quantitatively analyzed. RESULT(S): From February 1, 2000, to March 31, 2001, videotaped ETs from 23 pairs of pregnant and nonpregnant cycles were identified. Embryo placement was more shallow in pregnancy cycles than in nonpregnancy cycles. The groups did not differ in the absolute distance of embryo placement to the fundus, ovarian stimulation, or other features of the ET. CONCLUSION(S): The transfer point may serve as a better marker of embryo position than does the absolute distance to the uterine fundus.