Low dose stimulation (LS) is emerging as an alternative regime in assisted reproductive technology (ART). This study aimed to compare the cost-effectiveness of LS to the high dose GnRH antagonist (Atg) regime.
A total of 341 fertilized and 37 unfertilized oocytes from 63 intracytoplasmic sperm injection (ICSI) treatment cycles were included for retrospective assessment using the Embryoscope time-lapse video system. The second polar body (pb2) extrusion occurred at 2.9±0.1 h (range 0.70-10.15 h) relative to sperm injection. All oocytes reduced in size following sperm injection (p<0.05) with shrinkage ceasing after 2h in the unfertilized and at pb2 extrusion in the fertilized oocytes. Pb2 extrusion was significantly delayed for women aged >38 years compared to those <35 years (3.4±0.2 vs. 2.8±0.1, p<0.01) or 35-38 years (3.4±0.2 vs. 2.8±0.1, p<0.01), but timing was not related to the Day 3 morphological grades (1-4) of subsequent embryos (2.9±0.1, 2.9±0.1, 2.8±0.2 and 3.0±0.1; p>0.05 respectively). A shorter time of first cleavage division relative to either sperm injection or pb2 extrusion is associated with both top grade (AUC=0.596 or 0.601, p=0.006 or 0.004) and usable embryos (AUC=0.638 or 0.632, p=0.000 respectively) on Day 3. In summary, (i) pb2 of human oocytes extrudes at various times following sperm injection, (ii) the timing of pb2 extrusion is significantly delayed when female age >38 years, but not related to subsequent embryo development, (iii) all human oocytes reduce in size following sperm injection, (iv) completion of pb2 extrusion in the fertilized oocytes is a pivotal event in terminating shrinkage of the vitellus, and (v) time to first cleavage division either from sperm injection or pb2 extrusion is a significant predictive marker for embryo quality on Day 3.
Advanced age is an increasing trend for both males and females seeking in vitro fertilization (IVF). This retrospective cohort study investigated the outcomes of 1280 IVF-related treatment cycles, selecting the first treatment for couples utilizing autologous gametes and who underwent single fresh embryo transfer. Males aged 40-49 years had a 52% reduction in normal sperm motility, while it was markedly reduced by 79% at 50 years or older. However, neither semen parameters nor male age were predictive of clinical pregnancy or live birth chance. In a combination of age groups, cases with Younger Females had the greatest chance of successful outcomes and this was independent of having a younger or older male partner. Specifically, Young Female-Young Male combinations (≤ 35 years) were the most likely to succeed in achieving a clinical pregnancy or live birth (OR 2.84, p 35 years, respectively) had a similar increased chance (OR 2.07, p