P-130 Morphokinetic analysis of early human embryo development and its relationship to endometriosis resection: a retrospective time-lapse study with the use of KIDScore D3 and D5
Authors: Staib C , Herbert S.L , Schwab M , Wöckel A , Häusler S 
Published: June 2022

Abstract

Study question
Does complete resection of endometriosis improve embryo quality as assessed by morphokinetic parameters using time-lapse microscopy?

Summary answer
Complete resection of endometriosis in affected women undergoing assisted reproduction is shown to have a positive impact on embryo morphokinetic parameters represented in embryo quality.

What is known already
Endometriosis is one of the most common gynaecological diseases. It is characterized by the presence of cells comparable to those in the endometrium but being located outside of the uterine cavity. About 4-30% women of child-bearing age are affected by endometriosis. In vitro fertilization (IVF) studies have suggested that women with more advanced endometriosis have poor ovarian reserve, low oocyte and embryo quality and poor implantation rates. Moreover inflammatory peritoneal fluid shows a toxic effect on embryos. This might have an impact on morphokinetic timings but there is only limited data available concerning morphokinetics and endometriosis.

Study design, size, duration
246 embryos (endometriosis group: n = 85; non-endometriosis control group: n = 115; complete resection of endometriosis= 46) undergoing infertility treatment at our clinics were included in this retrospective study. Inclusion criteria were female patients aged between 18 and 45 years undergoing IVF and / or ICSI treatment. The in vitro culture was performed in a closed time-lapse incubator (EmbryoScope®, Vitrolife) up to day 3 or in a prolonged culture up to day 5.

Participants/materials, setting, methods
Patient treatment included conventional insemination or intracytoplasmatic sperm injection. IVF inseminated or ICSI injected oocytes were culturd in the TimeLapse monitoring incubator. Embryos were cultured for 3 to 5 days without media change at 6.8% CO2 and 5% O2 at 37°C. During embryo culture morphokinetic parameters and events were constantly annotated. Analysis was performed using the EmbryoViewer software and evaluated applying KIDScoreTM D3 or KIDScoreTM D5 according to the day of embryo transfer.

Main results and the role of chance
The analysis revealed a median KIDScoreTM D5 of 2.3 (on a scale from 1 to 9.9) for embryos from patients suffering from endometriosis without complete resection. The control group without endometriosis achieved a score of 7.0 (p = 0.001). The median for embryos from endometriosis patients with complete resection was 7.1 which meant a significant increase compared to embryos from patients without complete resection (p = 0.002).
Effect size according to Cohen showed a moderate up to strong biological effect (r = 0.4) for complete resection vs. no resection of endometriosis. For the three groups KIDScoreTM D3, pregnancy rates as well as abortion rates showed the same clinical trends.
Additionally, we could describe a series of four patients undergoing IVF-cycles before and after a complete resection of their endometriosis. As expected, in three out of four cases they showed a clear increase in their embryo quality after complete resection of endometriosis.

Limitations, reasons for caution
The main limitation of the study is the relative small sample size of the groups, especially the number of patients with endometriosis resection. Additionally, the study is limited to its retrospective design.

Wider implications of the findings
Pathogenesis of endometriosis related infertility is multifactorial and not completely understood. But knowing that endometrioid lesions produce inflammatory cytokines which are toxic for oocytes and embryos, resection of the lesions in order to reduce inflammation seems to be a plausible approach.

Trial registration number
20191007 01