IMSI (Intracytoplasmic Morphologically Selected Sperm Injection)

Intracytoplasmic morphologically selected sperm injection (IMSI) represents a more sophisticated method of performing ICSI (see section on ICSI) whereby, prior to injection, the sperm is selected at a higher magnification. As such, selection of the sperm might be improved versus traditional ICSI, specifically by showing sperm head vacuoles that are not necessarily seen at lower magnifications1,2.



There is some evidence to suggest that the use of high-magnification sperm selection may be associated with higher pregnancy and lower miscarriage rates and decreased risk of major birth defects3-7. However, still to date, there is a lack of evidence from randomised controlled trials on the beneficial use of IMSI. Hence, the most relevant indications for IMSI still remain to be determined.


In view of the scarcity of head-to-head IMSI versus ICSI or IVF studies, indications for IMSI may include recurrent implantation failure and recurrent miscarriage. All other potential indications of IMSI require further investigation. As the use of IMSI is not evidence based with respect to improving livebirth rates and is optional, the clinic will only offer it when your consultant deems it appropriate for your treatment. The CRGH will offer IMSI in order to reduce the chance of miscarriage and/or implantation failure.

The risks associated with the use of ICSI also apply to IMSI; there is no significant risks to the patient or embryo.

IMSI is outlined as an additional treatment option by the Human Fertilisation and Embryology Authority (HFEA) and has currently been deemed as red in the HFEA traffic light system for additional treatment options as there is no evidence from randomised controlled trials to show that it is effective at improving the chances of having a baby for most fertility patients. Please refer to the treatment add-ons page of the HFEA website8.


Contact us

If you would like to book an appointment with one of our doctors you can:

  • Speak to the booking team on +44 (0)20 7837 2905  (Mon – Fri 8.30am – 6pm)
  • Email us on 
  • Visit our Appointments page, fill out the contact form and a member of the team will be in touch


  1. Boitrelle FGuthauser BAlter LBailly MBergere MWainer RVialard FAlbert MSelva J. High-magnification selection of spermatozoa prior to oocyte injection: confirmed and potential indications. Reprod Biomed Online. 2014; 28:6-13.
  2. De Vos, A. Polyzos, N., Verheyen, G. and Tournaye, H. Intracytoplasmic morphologically selected sperm injection (IMSI): a critical and evidence-based review. Basic Clin Androl. 2013; 23: 10.
  3. Duran-Retamal M, Morris G, Achilli C, Gaunt M, Theodorou E, Saab W et al. Livebirth and miscarriage rate following intracytoplasmic morphologically selected sperm injection vs intracytoplasmic sperm injection: An updated systematic review and meta-analysis. Acta Obstet Gynecol Scand. 2020; 99: 24-33
  4. Cassuto N, Hazout A, Bouret D, Balet R, Larue L, Benifla L et al., Low birth defects by deselecting abnormal spermatozoa before ICSI. Reprod Biomed Online 2014; 28:47-53.
  5. Teixeira D, Miyague A, Barbosa M, Navarro P, Raine-Fenning N, Nastri C, Martins W. Regular ICSI versus ultra high magnification IMSI sperm selection for assisted reproduction. Cochrane Database Syst Rev. 2020; 2:CD010167.
  6. Klement A, Koren Morag N, Itsykson P, Berkovitz A. Intracytoplasmic morphologically selected sperm inection versus intracytoplasmic sperm injection: a step toward a clinical alogorithm. Fertil Steril; 2013: 99:1290-3.
  7. Shalom-Paz E, Anabusi S,  Michaeli M, Karchovsky-Shoshan E,  Rothfarb N, Shavit T,  Ellenbogen A. Can intra cytoplasmatic morphologically selected sperm injection (IMSI) technique improve outcome in patients with repeated IVF-ICSI failure? a comparative study. Gynecol Endocrinol 2015;31:247-51

IVF Packages With Access Fertility

IVF Packages With Access Fertility
CRGH is partnering with Access Fertility to offer a series of IVF programmes and packages. For more information please click below.

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