P-325 Endometriosis has no negative effect on embryo quality and morphokinetics. A retrospective case control study
Authors: Assaf W , Kugelman N , Lahav-baratz S , Blais I , Koifman M , Skvirsky S , Ishay D , Wiener-Magenzi Z , Oron G , Younes G 
Published: June 2022

Abstract

Study question
Does endometriosis affect embryo quality assessed by a time-lapse morphokinetic model analysis?

Summary answer
Endometriosis does not seem to have a negative effect on embryo morphokinetics and embryo quality assessed by a time-lapse in-house model.

What is known already
Endometriosis is strongly associated with infertility. Clinical studies suggest lower implantation and pregnancy rates in women with endometriosis. Embryos of women with endometriosis exhibit a higher incidence of developmental delay and arrested development than those derived from women without the disease. Poor oocyte and embryo quality have been suggested as a possible cause.
It has been found that time-lapse systems which capture images of embryos at frequent time intervals allow continuous assessment of their quality. Developing an in-house model for embryo selection based on embryos with known implantation data (KID) enables detecting the highest quality embryos selected for transfer.

Study design, size, duration
A retrospective case control study between July 2013 and December 2020 which evaluated embryos from 58 ICSI cycles of women with endometriosis and 487 ICIS cycles of healthy women treated for male factor infertility. Morphokinetic parameters and rate of high-quality embryos were compared. High-quality was considered as: time to pronucleus fading (tPNf)&lt;24.08, T2&lt;26.6, S2&lt;0.9, and t8&lt;56 hours following insemination for cleavage embryos, and t2&lt;26.6, S2&lt;0.9, t8&lt;56 and time to start blastulation (tSB)&lt;96.6 hours for blastocysts.

Participants/materials, setting, methods
At a single infertility unit, women with endometriosis were compared to healthy women with male factor infertility as the control group. The main outcome was embryo kinetics which included: time to polar body extrusion (tPB2), time to pronucleus fading (tPNf), cleavage timings (t2-t8), synchrony of the second and third cycles (S2 and S3), duration of the second cycle (CC2) time to start blastulation (tSB). These parameters were set based on an in-house morphokinetic model.

Main results and the role of chance
We compared 154 embryos derived from 58 ICSI cycles of women with endometriosis to 1,387 embryos derived from 487 ICSI control cycles of couples with male factor as a single cause of infertility.There was a wider use of agonist protocol (48.3% vs 15.7%,p&lt;0.001) and a higher rate of nuliparity (81% vs 61.5%, p = 0.003) in women with endometriosis compared to the control group. Demographic and treatment parameters were comparable including: maternal age, BMI, Gravidity, number of cycles, gonadotropins dosage, basal serum FSH, basal serum LH, estradiol and progesterone level at the day of ovum pick-up, number of oocytes aspirated, number of mature oocytes. There was no difference in tPB2, tPNf, t2-t8, S2 and S3, CC2, tSB between the groups. The rate of top quality embryos was comparable for both groups; for day 3 p = 0.25 and for day 5 p = 0.72. Pregnancy rate for the study and control group was 38.8% and 45%, respectively, p = 0.36.

Limitations, reasons for caution
One limitation is the retrospective methodology. Endometriosis severity was not taken into account which might be a confounding factor. The strengths are a single center study with embryos cultured under the same standardized laboratory conditions. However, a larger scale study might be needed.

Wider implications of the findings
Time lapse in-house model is an additive informative tool for embryo quality. Opposed to what was thought so far, the use of our time-lapsed system demonstrated that embryos of women with endometriosis had similar quality to healthy women. This can be used to reassure women with endometriosis before IVF treatment.

Trial registration number
not applicable