Does cleavage- versus blastocyst-stage embryo transfer improve fertility rates in women over 38 years of age undergoing assisted reproductive technology?

OBJECTIVE: To evaluate whether extending embryo culture to day 5 (D5) affects pregnancy rates in women older than 38 years undergoing in vitro fertilization (IVF). METHODS: This retrospective, observational cohort study included data from fresh IVF cycles of women over 38 years, during 2011-2021. The cohort was divided according to day 3 (D3) versus D5 embryo transfer (ET). RESULTS: A total of 346 patients (ages 38-45 years) who underwent 496 IVF cycles were included, each yielding one to six embryos. A total of 374 (75%) fresh D3 ETs were compared with 122 (25%) D5 ETs. Demographically, there were more nulliparas in the D3 group (189 [50.9%] vs 47 [38.8%], P = 0.021). Higher gonadotropin dosage was used (3512 ± 1346 vs 3233 ± 1212 IU, P = 0.045) and lower maximum estradiol levels were reached in the D3 group (1129 ± 685 vs 1432 ± 708 pg/mL, P = 0.002). Thirty-three (27%) of the D5 cycles resulted in transfer cancelation due to failure of blastocyst formation (P = 0.001). However, clinical pregnancy rates (P = 0.958), live birth rates (P = 0.988), and miscarriage rates (P = 0.710) did not differ between D3 and D5 ETs. Multivariable logistic regression for clinical pregnancy rate showed that day of transfer did not have a significant effect on the odds (P = 0.376), but maternal age (P = 0.001) and number of retrieved oocytes (P = 0.009) were significant variables. CONCLUSIONS: In older women, culturing embryos to blastocyst stage can decrease invalid ETs without reducing pregnancy rates. Cancelation rates are higher but it may avoid interventions and conserve valuable time.

Oocyte retrieval in social fertility preservation: challenging traditional beliefs on gonadotropin dosing and follicular size.

OBJECTIVES: To investigate treatment approaches for fertility preservation patients, with a focus on timing of oocyte retrieval, and to determine whether their characteristics differ from those of other IVF patients. Additionally, to evaluate the significance of follicle size on triggering day in the context of fertility preservation. METHODS: This retrospective cohort study was conducted in a tertiary, university-affiliated medical center. It compared 140 matched patients undergoing social fertility preservation to 140 patients undergoing IVF treatment due to male factor infertility. RESULTS: Patients undergoing fertility preservation received a higher initial gonadotropin dose and had more oocytes retrieved than the control group. Within the fertility preservation cohort, a negative correlation was observed between the rate of large follicles and the number of retrieved oocytes. While there was no significant association between rate of large follicles and oocyte maturation rate in the entire group, age-stratified analysis revealed a negative relationship. Analysis revealed that although traditional treatment determinants such as follicular size and gonadotropin dosing were considered, peak estradiol levels were consistently identified as significant predictors of treatment outcomes. CONCLUSIONS: Physicians may modify treatments for fertility preservation, emphasizing a higher gonadotropin dosage to maximize oocyte retrieval. Elevated estradiol levels can serve as a real-time predictive marker for the number of mature oocytes. While treatment strategies can influence outcomes, intrinsic patient factors, particularly baseline ovarian function, remain crucial. These results challenge beliefs regarding the importance of larger follicles and suggest the need for a tailored approach, considering patient age and specific fertility preservation objectives.