Dados do Trabalho

Title

Correlation of female and male factors in the embryonic development arrest

Objective

To evaluate the relevance of female and male factors in vitro fertilization (IVF) cycles where embryonic development arrest occurred.

Methods

Descriptive observational case series study in which IVF cycles were analyzed from January 2020 to December 2022, in which embryos did not develop to the blastocyst stage (vs. embryonic development arrest). Couples undergoing ovarian stimulation for ICSI with their own eggs and semen from spontaneous ejaculation were included in the study. Cycles using frozen eggs, donated eggs, frozen semen, testicular/epididymal semen, and donated semen were excluded from the study. The following variables were examined: couple's age, body mass index (BMI), type of ovarian stimulation protocol, number of mature eggs (MII), fertilization rate, day of embryonic arrest and oocyte quality; which was evaluated based on the number of morphological alterations (normal: up to 2/mild: 2-3/severe: ≥3). Among male factors, in addition to age and BMI, the type of semen preparation and quality were also observed, which was classified according to Kruger's morphology as normal (≥4%), mild alteration (2-4%), and severe alteration (≤1%).

Results

During the study period, 297 ICSI cycles with arrested embryonic development were screened, of which 128 were excluded. 169 cycles were included in the study according to predefined inclusion criteria. In the general analysis of the data, it was observed that the maternal average age was 40.4 years (±3.5), being under 38 years (24.2%) and over 38 years (75.7%), among which 9.6% were obese (Average BMI: 24.2 ± 3.9). The most used ovarian stimulation protocols were: 225 HMG (45.6%), 31.4% of the low responders used the minimal ovarian stimulation protocol (clomiphene citrate 50 mg/day associated with 150 recombinant (r) FSH + 75 HMG on alternate days) and 18.3% used 150 FSH (r) + 75 HMG. Pituitary blockade was performed with GnRh Antagonist (68.6%) or Dydrogesterone 10 mg/day (31.4%); and the types of “trigger ovulation”: Dual Trigger (93.5%), GnRh Agonist (4.7%) and HCGr (1.8%). The average number of days of ovarian stimulation was 10. A total of 567 mature eggs were recovered, with an average of 3 MII per case, with a fertilization rate of 78% (± 23%). Most ovules had severe alterations (75.3%) and the average time of embryonic arrest was on the 6th day of development (50.3%). Men average age was 41.9 (± 7.4) years, with a avarage BMI of 27.8 (± 4.5). Regarding seminal quality, severe alterations were found in most cases (82.8%) and the main preparation method used was swim-up (50%), followed by washing (32.9%).

Conclusion

In IVF treatments, the blastocyst formation rate is a key determinant for reproductive success. Inefficiency of embryonic development is associated with a variety of female and male factors. However, correlating embryonic arrest with only one factor would not be plausible, as this study showed that the majority of women were above 38 years old, which could have already predicted poor oocyte quality and compromise embryo development, despite a good fertilization rate. Therefore, prospective studies with more homogeneous groups will be necessary to better elucidate the causal factors.

Keywords

embryonic arrest, embryonic development arrest, IVF/ICSI.