Preimplantation genetic testing for aneuploidy (PGT-A)-a single-center experience.

PURPOSE: The aim of this study was to determine the prevalence and nature of human embryonic aneuploidy based on the preimplantation genetic testing for aneuploidy (PGT-A), the distribution of aneuploidy across the individual chromosomes, and their relationship to maternal age. METHODS: This is a retrospective cohort study conducted at a single center. The study includes subjects who opted for PGT-A in their in vitro fertilization (IVF) cycle from 2016 to 2020. PGT-A was performed on 1501 embryos from 488 patients in 535 cycles. PGT-A was performed using NGS-based technique on Ion Torrent PGM (Life Technologies). Analysis was performed to determine the (i) frequency of the aneuploidy, (ii) the chromosome most commonly affected, (iii) relationship between maternal age and the rate of aneuploidy, and (iv) incidence of segmental aneuploidy. RESULTS: The overall frequency of aneuploidy was observed to be 46.8%. The incidence of aneuploidy rate was ~ 28% at maternal age < 30 years which steadily increased to ~ 67% in women above 40 years. High frequency of aneuploidy was observed in chromosomes 16, 22, 21, and 15. Segmental abnormalities, involving loss or gain of chromosomal fragments, were observed at a frequency of 5.3%, and highest incidence of segmental gain was observed on the q-arm of chromosome 9. CONCLUSION: The study provides important information regarding the frequency of the aneuploidy in IVF cohort and the most frequent chromosomal abnormality. The study further emphasizes the relationship between maternal age and aneuploidy. This study has important implications which help clinicians and genetic counselors in providing information in patient counseling.

A Study to Find Optimal Intra-cytoplasmic Sperm Injection Timing of Oocytes Matured from Germinal Vesicle in in Vitro Maturation Cycles Using a Time Lapse System.

BACKGROUND: The use of in vitro maturation (IVM) has allowed patients with polycystic ovary syndrome (PCOS) to have a positive fertility outcome, as it allows utilisation of immature oocytes to mature in vitro. AIM: The aim of the study is to establish an optimum intra-cytoplasmic sperm injection (ICSI) timing for IVM oocytes (germinal vesicles [GV] →, metaphase I [MI]→ and metaphase II [MII]) using time lapse system (TLS) for patients with PCOS. SETTING AND DESIGN: Patients included in this study were diagnosed with PCOS, ≤35 years of age, anti-Müllerian hormone levels >6 ng/ml and antral follicle counts <40. Furthermore, we included only GV oocytes at the time of denudation in our study. MATERIALS AND METHODS: Patients were minimally stimulated and their oocytes were retrieved. In vitro maturated oocytes were monitored using TLS to a maximum of 30 h. MII oocytes were further cultured and injected at five different time intervals (1-2 h, 3-4 h, 5-6 h, 7-8 h and >8 h) to observe for fertilisation, cleavage and utilisation rate. STATISTICAL ANALYSIS: Chi-square test was applied to compared the treatment groups. RESULTS: Amongst 328 oocytes retrieved from 27 female patients, 162 oocytes were in the time-monitored cohort and 162 oocytes were grouped as the control cohort. Maturation rate between GV→ MII was highest at 18 h in the time-monitored cohort MII (n = 57). Utilisation rate was highest when ICSI was performed between 5 and 6 h after the first polar body extrusion, n = 17 (63%). CONCLUSION: This study provides valuable insight into the optimal maturation timing using a TLS to yield the good number of oocytes. In addition, optimising ICSI timing is important to provide the best utilisation rate in an IVM cycle to achieve synchrony between nuclear and cytoplasmic maturation.