P-354 Endometriosis is negatively associated with morphokinetic indicators of embryo developmental competence.
Authors: Sanchez A M , Vitali M , Guglielmo M C , Gippone S , Vitale G S , De Ponti E , Briganti C , Dal Canto M , Buratini J , Mignini Renzini M 
Published: June 2023

Abstract

Study question
Is endometriosis associated with poorer embryo quality as assessed by fertilization and cleavage morpkokinetics?

Summary answer
Endometriosis is negatively associated with embryo quality as assessed by fertilization and cleavage morpkokinetics.

What is known already
The negative association between endometriosis and fertility is well-known. However, whether it predominantly derives from decreased oocyte quality or compromised endometrial receptivity is still an open question. Studies on the impact of endometriosis on oocyte/embryo developmental competence have generated discrepant results. Our group has generated strong evidence that fertilization and cleavage morphokinetics accurately reflects embryo quality. Recently, we have developed a scoring system (A-D) based on early morphokinetic parameters capable of guiding the selection of embryos with higher competence to achieve a live birth, being “A” the embryos with the highest morphokinetic score and “D” the embryos with the poorest.

Study design, size, duration
Retrospective non-interventional study, including patients who underwent IVF/ICSI cycles at the Biogenesi Reproductive Medicine Centre, Monza, Italy from 2018 to 2022. The morphokinetic profiles of embryos produced in 283 cycles of patients with endometriosis (diagnosed by laparoscopic examination as stage III-IV, moderate/severe; ASRM criteria ) were compared with those of embryos produced in 1336 cycles of patients presenting tubal or unexplained infertility factor (control).

Participants/materials, setting, methods
The study includes 1290 embryos from patients with endometriosis and 6197 control embryos. Embryo culture was performed in a time-lapse incubator. Embryos were retrospectively classified with 4 scores (A, B, C and D) derived from early morphokinetic parameters (tPNf, t2 and t4).
Patient/cycle characteristics and outcomes and morphokinetic parameters were compared using Fisher’s (percentages) or Wilcoxon sum rank (continuous variables) tests. Differences in the distribution of morphokinetic scores were assessed with the Chi-square test.

Main results and the role of chance
Maternal age (36.3±3.9 vs 37.5±4.1 years; p &lt; 0.0001), number of oocytes retrieved (7.4±5.3 vs 9.6±5.5; p &lt; 0.0001) and BMI (22.0±3.2 vs 22.6±3.7; p = 0.039) were lower in patients with endometriosis as compared to controls. Embryos from patients with endometriosis reached tPNFa (h) (6.6±1.6 vs 6.4±1.6; p = 0.013), tPNf (h) (24.5±3.6 vs 24.2±3.6; p = 0.002) and t2 (h) (27.2±3.7 vs 26.9±3.8; p = 0.002) later than control embryos. In addition, the distribution of morphokinetic scores differed between groups; patients with endometriosis produced a lower percentage of A embryos (34.7% vs 41.0%) and a higher percentage of D embryos as compared to control patients (43.5% vs 39.6% respectively; p &lt; 0.001). A multivariate analysis revealed that the negative association between endometriosis and achievement of the morphokinetic score A is independent of maternal age, paternal age, presence of male infertility factor and maternal BMI (OR 0.75; 95% IC 0.65-0.86; p &lt; 0.0001).

Limitations, reasons for caution
The study is limited by its retrospective nature and other potentially interfering variables not included in the analysis.

Wider implications of the findings
Our findings indicate that endometriosis is associated with reduced embryo developmental competence as assessed by early morphokinetics. Therefore, while suggesting that endometriosis can indeed affect oocyte quality, our data shed light on the mechanisms linking this pathology with subfertility.

Trial registration number
Not Applicable