Ranji GG, Shankar K, Asokan Y, Veerasigamani G, Vittal RG, Naaram NM, Hema Niveda KR. Impact of Post-Thaw Incubation Time of Frozen Embryos on Clinical Pregnancy Rate.
J Hum Reprod Sci 2023;
16:64-69. [PMID:
37305777 PMCID:
PMC10256942 DOI:
10.4103/jhrs.jhrs_180_22]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2022] [Revised: 02/24/2023] [Accepted: 02/25/2023] [Indexed: 06/13/2023] Open
Abstract
Background
Vitrification of embryos following a single-controlled ovarian stimulation has been the strategy practised now in many in vitro fertilisation clinics to minimise the risk of early ovarian hyper stimulation syndrome, to reduce multiple pregnancy rates and to improve cumulative pregnancy rates. In recent years, advances in vitrification techniques and improved culture conditions have led to good post-thaw embryo survival rates, thereby increasing pregnancy rates of frozen embryo transfer (FET) cycles.
Aim
The aim of this study was to analyse the effect of post-thaw incubation time of frozen embryos on the clinical pregnancy rates (CPRs) of frozen embryo transfer (FET) cycles.
Settings and Design
This was a retrospective, comparative study done at a teaching hospital in assisted reproductive treatment.
Materials and Methods
Three hundred and ten FET cycles were analysed, of which 125 had day 2 freezing and 185 had day 3 freezing. Depending upon the day of thawing and day of transfer, FET cycles were divided into six groups: Group 1 (day 2 thawing and day 3 transfer), Group 2 (day 2 thawing and day 4 transfer), Group 3 (day 2 thawing and day 5 transfer), Group 4 (day 3 thawing and day 3 transfer), Group 5 (day 3 thawing and day 4 transfer) and Group 6 (day 3 thawing and day 5 transfer).
Statistical Analysis Used
Statistical analysis was performed using version 14 R software version 4.0.1 (2020-06-06) (R foundation for Statistical Computing, Vienna, Austria). A P < 0.05 is taken as significant.
Results
The CPR of Group 4 was 42.4% which was more than that of the other groups but it did not reach statistical significance.
Conclusions
Short incubation time of 2-4 h is as effective as an extended incubation time in terms of CPRs of FET cycles.
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