Efficacy of dual progesterone administration (intramuscular and vaginal) for luteal support in fresh day 3 or day 4 embryo transfer cycles.

OBJECTIVE: The aim of this study was to compare in vitro fertilization outcomes between fresh day 3 or day 4 embryo transfer cycles with dual progesterone (P) administration (intramuscular and vaginal) and cycles with single intramuscular P administration for luteal support. METHODS: We selected 124 cycles from 100 women (under age 40 years) who underwent oocyte pick-up (number of trials ≤ 3, 4-14 oocytes obtained) and transfer of two or three day 3 or day 4 embryos at two infertility centers from January 2014 to June 2019. Dual P (intramuscular P [50 mg] daily+vaginal P) was used in 52 cycles and a single intramuscular administration of P (50 mg daily) was used in 72 cycles. RESULTS: Women's age, infertility factors, number of oocytes retrieved, number of transferred embryos, and mean embryo score were similar between the dual P group and the single P group. Although the number of trial cycles was significantly higher (1.9 vs. 1.5), and the mean endometrial thickness on the trigger day (10.0 mm vs. 11.0 mm) was significantly lower in the dual P group, the implantation rate, clinical pregnancy rate, ongoing pregnancy rate, and miscarriage rate for both day 3 and day 4 transfers were similar between the two groups. CONCLUSION: In fresh day 3 or day 4 embryo transfer cycles, dual P administration did not demonstrate any clinical advantages. Intramuscular P alone appears to be sufficient for luteal support.

Predictors of blastocyst formation rate in elective day 5 transfer cycle.

This study aimed to investigate the factors affecting blastocyst formation rate. One hundred and seven fresh in vitro fertilisation (IVF) and elective day 5 blastocyst transfer cycles were selected. Univariate and multivariate analyses revealed that intracytoplasmic sperm injection (ICSI) (r = -.236, p = .014 vs. p = .005) was advantageous for blastocyst formation. In addition, the number of mature oocytes (r = -.274, p = .004 vs. p = .002) was a significant factor associated with blastocyst and good-quality blastocyst formation rates (p = .021, r = -.389). Both blastocyst and good-quality blastocyst formation rates were significantly higher with ICSI than with conventional insemination (65.0 ± 24.5% vs. 50.0 ± 21.2%, p = .012; 43.1 ± 22.8% vs. 30.9 ± 19.8%, p = .038, respectively). The number of mature oocytes appears to be the most important predictor of blastocyst formation rate. Additionally, ICSI fertilisation is superior to conventional insemination in terms of blastocyst formation rate.IMPACT STATEMENTWhat is already known on this subject? There are many advantages of blastocyst transfer cycle over cleavage transfer cycle, but there are no known routine selection criteria for the timing of embryo transfer. To date, the number of blastomeres, number of retrieved oocytes, quality of embryos and fertilisation method have been suggested as the important factors involved in blastocyst formation. However, the number of studies on this issue is limited, and some studies have shown conflicting results.What do the results of this study add? This study showed that the number of mature oocytes and ICSI fertilisation are the significant factors associated with blastocyst formation rate in elective day 5 transfer cycle.What are the implications of these findings for clinical practice and/or further research? This paper demonstrated that the number of mature oocytes and the fertilisation method should be considered before embryo transfer. Consideration of these factors would be meaningful in selecting patients who will be suitable for extended culture up to day 5.

Specific tail swelling pattern in hypo-osmotic solution as a predictor of DNA fragmentation status in human spermatozoa.

OBJECTIVE: The aim of this study was to investigate DNA fragmentation status in human spermatozoa according to specific tail swelling patterns determined via hypo-osmotic swelling test (HOST). METHODS: Frozen semen samples from 21 healthy donors were thawed and prepared by the swim-up technique for use in intracytoplasmic sperm injection. The semen samples were treated for 5 minutes as part of the HOST procedure and then underwent the sperm chromatin dispersion test using a Halosperm kit. DNA fragmentation status (large halo, medium halo, small halo, no halo, or degraded) and the specific tail swelling pattern ("a"-"g") were assessed at the level of a single spermatozoon. A total of 42,000 spermatozoa were analyzed, and the percentage of spermatozoa without DNA fragmentation (as evidenced by a large or medium halo) was assessed according to the specific tail swelling patterns observed. RESULTS: The HOST examinations showed that >93% of spermatozoa across all types displayed no DNA fragmentation. The percentage of spermatozoa without DNA fragmentation was 100% in type "d", 98.67% in type "g", and 98.17% in type "f" spermatozoa. CONCLUSION: We found that the type "d" spermatozoa displayed no DNA fragmentation, but the other types of spermatozoa also displayed very low rates of DNA fragmentation. This result may be associated with the processing of the spermatozoa by density gradient centrifugation and the swim-up technique.