P-150 Comparison of morphokinetic parameters of embryos generated from Capacitation In-vitro Maturation and Controlled ovarian stimulation-ICSI
Authors: Phuong L , Dang T , Nguyen T , Le A , Pham T , Vuong L 
Published: June 2023

Abstract

Study question
Is there any difference in the embryo morphokinetic parameters between embryos generated from Capacitation – In-vitro maturation (CAPA-IVM) and Controlled ovarian stimulation – ICSI (COS-ICSI)?

Summary answer
Embryos generated from CAPA-IVM cycles reached tPNa, t2, t4, t8, tSC, tM, tSB, and tB significantly later than COS-ICSI embryos.

What is known already
IVF with ovarian hyperstimulation has limitations in some subgroups of women at high risk of ovarian stimulation, such as those with polycystic ovary syndrome. IVM may be a feasible alternative to IVF in women with a high AFC. A recent randomized controlled trial produced statistically inconclusive findings regarding the noninferiority of the CAPA-IVM technique compared with COS-ICSI. Moreover, there is a lack of studies investigating the impact of CAPA-IVM on the morphokinetic parameters of embryos.

Study design, size, duration
This is a retrospective cohort study conducted from March 2021 to March 2022. The study included 115 couples (68 couples used CAPA-IVM, 47 couples used COS-ICSI) who had their embryos cultured to the blastocyst stage using a time-lapse system.

Participants/materials, setting, methods
The study was conducted at My Duc Phu Nhuan hospital, Ho Chi Minh City, Vietnam. Couples aged  ≤ 40 years old, had blastocyst culture using time-lapse system were included in the study. Couples used oocyte or sperm donation, PGT treatment, had severe male factors, and fertilization failure in previous cycles were excluded. We analyzed 392 blastocysts from 115 couples for morphokinetic parameters including tPNa, tPNf, the onset of t2 to t8, tSC, tM, tSB, and tB.

Main results and the role of chance
There was no difference in tPNf, t3, and t5 between embryos from CAPA-IVM and COS-ICSI. However, embryos generated from CAPA-IVM reached tPNa, t2, t4, t8, tSC, tM, tSB, and tB significantly later than COS-ICSI embryos [tPNa (9.3 2.0 vs 8.0 1.9; P &lt; 0.001), t2 (27.4 3.7 vs. 25.5 3.1; P &lt; 0.001), t4 (38.7 4.5 vs. 37.3 4.3; P = 0.004), t8 (58.9 9.2 vs. 56.3 8.4; P = 0.011), tSC (76.2 11.1 vs. 71.4 10.4; P &lt; 0.001), tM (90.4 8.6 vs. 85.5 10.0; P &lt; 0.001); tSB (101 8.1 vs. 97.1 8.3; P &lt; 0.001) and tB (108 7.6 vs 106 7.7; P &lt; 0.05)]. The frequency of direct cleavage in the first and the second cell division cycle was similar between two groups (58.6% vs. 30.0%; 41.4% vs. 70%, respectively, P &gt; 0.05).

Limitations, reasons for caution
The retrospective cohort study design could limit the ability to eliminate sources of bias. The characteristics of participants may influence the study findings, i.e. women in the CAPA-IVM group were PCOS while women in the COS-ICSI were not. In addition, the study population's single-ethnicity nature limits the results' external generalizability.

Wider implications of the findings
This study found that embryos from CAPA-IVM reached tPNa, tPNf, t2, t4, t8, tSC, tM, tSB, and tB significantly later than COS-ICSI. The findings of this study provide evidence for further studies to evaluate CAPA-IVM embryos and to improve the CAPA-IVM culture system.

Trial registration number
Not Applicable