Assisted Reproductive TechniqueRA-ICSINCT02271490
Acrosome Reaction Induction Prior to ICSI
A study testing Acrosome Reaction induction and capacitation in incubation medium prior to ICSI in people with Assisted Reproductive Technique and ICSI, run by Assistance Publique - Hôpitaux de Paris at 1 site in France.
Trial summary
Introduction To get through the egg vestment and fertilize the oocyte, the spermatozoon uses its acrosomal enzymes. When Intracytoplasmic sperm microinjection (ICSI) is performed, the acrosomal enzymes are introduced with the spermatozoa inside the ooplasme. Read more about this study
- Who is it for?
- Ages 18 to 43 years
- Conditions the study is for
- Assisted Reproductive Technique, ICSI, Acrosome Reaction
- What is being tested?
- Acrosome Reaction induction and capacitation in incubation medium prior to ICSI
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 111 participants
- Where
- 1 siteFrance
- Study dates
- 13 Dec 2014to 18 Dec 2015
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 43 years
- All sexes
- No healthy volunteers
- Adult
Who may be able to join
- Couples involved in an ICSI program
- First attempt only
- Cohort with at least 6 oocytes
Who cannot join
- No social security number
- No signed consent form
- Surgically retrieved sperm
Trial locations and contacts
1 site in 1 country.
About this study
Official title: Improvement of the Post ICSI Pregnancy Outcome by Induction of the Acrosome Reaction Prior to ICSI
Introduction To get through the egg vestment and fertilize the oocyte, the spermatozoon uses its acrosomal enzymes. When Intracytoplasmic sperm microinjection (ICSI) is performed, the acrosomal enzymes are introduced with the spermatozoa inside the ooplasme.
The fate of these enzymes, that normally never enter the oocyte, is not known. But they impair the embryo development.
Read more
Indeed, although the ICSI outcome is satisfactory in humans, a series of studies in many species (mouse, hamster, cattle, and horse) demonstrate the deleterious effects of the introduction of acrosomal material in the oocyte cytoplasm, on embryo and fetal development. These studies have also shown two things:
- The bigger the acrosome, the more deleterious are the effects of their introduction into the egg.
- And that the induction of the acrosome reaction (AR) prior to ICSI significantly improves embryonic development and the number of babies born after embryo transfer as it is the case in the mouse. The microinjection of acrosome reacted sperm increases from 40 to 70 % the percentage of pups born per embryo transferred.
Hypothesis :
It is possible to improve ICSI outcome, in terms of babies born in human, by induction of the AR prior to microinjection.
After studying several techniques, we choose a physiologic technique for acrosome induction.
The induction of acrosome reaction prior to ICSI should improve in utero fetal development and decrease the rate of miscarriage and pregnancy arrest.
Read the detailed description
- Introduction Intracytoplasmic sperm microinjection (ICSI) produces 70% of fertilized oocytes and zygotes which mostly develop normally. To perform ICSI, a spermatozoon is taken from a sperm suspension after gradient migration. It is then immobilized by breaking its flagellum using a micropipette, and introduced into the oocyte cytoplasm. The rate of spontaneous acrosome reaction in humans is less than 20 %. Two studies on the percentage of acrosome reacted and immobilized sperm showed that 95% of them have a destabilization of the membrane but only 17.8% of them had made a full RA. In other words, when we microinjected 10 spermatozoa, only 2 of them are completely rid of their acrosome material. All others are introduced into the oocyte with acrosomal material. But this material does not normally enter the oocyte since the acrosome reaction is a prerequisite to the passage of the zona pellucida that surrounds the egg . The importance of using an acrosome-reacted spermatozoon for the success of ICSI has been previously highlighted in several animal species. It has been demonstrated that the induction of the acrosome reaction in mice lead to higher fertilization rates (from 30% to about 60 % ) . It is similar, in the rabbit and horses . Kimura et al. also reported that mouse oocytes injected with acrosome-intact rabbit and hamster sperm exhibited a nuclear activation and cessation of embryonic development without reaching the two-cell stage. This "cytotoxicity" of the same sperm disappears when they are released from their acrosomes before injection. In another study, the detrimental effect on oocyte survival of the presence of the acrosome during the injection of sperm heads was demonstrated in the golden hamster. All oocytes microinjected with acrosome-intact sperm were dead, while only those injected with acrosome reacted sperm have not only survived, but have also developed to the stage of two pronucleus in 79 % of cases and helped to get live births ( 19%). The team of Yanagimachi reported a study on the potentially dangerous effect of the incorporation of the sperm acrosome of different species within mouse oocytes. According to these authors, harmful components would probably be the enzymes such as trypsin-like acrosine and hyaluronidase, since their injection mimicked the effects of ICSI with acrosome-intact sperm. In the same study, it was confirmed that the toxic effects were correlated with the size of the acrosome and therefore the contents of protease enzymes. The toxic effects of the acrosome and its contents have been described explicitly by Morozumi and Yanagimachi. It induces deformation of the oocyte with an irregular appearance, edema or cytolysis with a pseudo-vacuolated cytoplasm appearance. Furthermore, it has been established that the damage caused by exogenous or acrosomales enzymes were correlated with oocyte cytoskeleton disruption through an aberrant accumulation of microtubules in the cortex of the oocyte. In addition to the morphological and ultrastructural alterations in the oocyte, the incorporation of the acrosome may result in a lack of nuclear activation of the oocyte. Kasai et al. reported that the completion of oocyte meiosis occur faster if the sperm was released from the acrosome. Similarly, an increase in fertilization rate after ICSI with acrosome reacted sperm was observed in pigs. The study by Morozumi et al. also demonstrated that the induction of the acrosome reaction of sperm from several species prior to ICSI resulted in an acceleration of oocyte activation, which was manifest in human spermatozoa. This was evidenced by the significant differences between the profiles of calcium oscillations after ICSI with acrosome-intact or acrosome-reacted sperm. Calcium waves recorded in oocytes injected with acrosome-reacted spermatozoa were characterized by an early onset and amplitude and a higher frequency. In contrast, the calcium response was abnormally delayed in oocytes injected with acrosome-intact sperm. Thus, altered calcium oscillations, the "key" oocyte activation signals during ICSI, is the cause of abnormal pre-implantation embryo development to the blastocyst stage. Indeed, the proportion of live healthy mice births is increased from 40% to 71%, when intact or acrosome-reacted sperm are microinjected, respectively . These same studies have also shown two things:
- The introduction of acrosomal material is more harmful when the quantity is large compared to the oocyte volume. There is therefore interest in systematically reducing the amount of material introduced into the oocyte cytoplasm to improve embryonic development.
- The second thing is that the induction of the acrosome reaction before ICSI greatly improves embryonic development and therefore the number of babies born from embryo transfer. Although ICSI in human gives very satisfactory results, the rate of infants obtained by embryo is lower than after IVF embryos transfer. Hence, there is a possibility of improving the results of ICSI by induction of the acrosome reaction prior to microinjection. After several studies we used incubation of spermatozoa with the follicular fluid (FF) of the partner to induce the spermatozoa acrosome reaction (Karim Rahal, 2011 Master Thesis 2). FF is indeed a potent inducer of the AR. There is no problem of traceability since the FF of the patient is used only for the sperm of her husband. This technic can be applied to the poorest semen. Finally, the technique is used in a very easy routine, since the follicular fluid is always recovered during oocyte retrieval and thus available.
- Hypothesis A preliminary study was run in human on microinjection of spermatozoa that were selected for their acrosomal status by birefringence microscopy. It showed that it improves the implantation rate from 24,4 % to 39 % . We therefore hypothesize that the improvement in the implantation rate of embryos obtained by ICSI after acrosomal induction as well as the reduction of miscarriage rate may result in improved clinical pregnancy outcome and birth rates of about 10 %.
- Being tested
- Acrosome Reaction induction, capacitation in incubation medium prior to ICSI
- Keywords
- Assisted Reproductive Technique, ICSI, Acrosome Reaction, Pregnancy outcome
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Acrosome Reaction inductionOther
capacitation in incubation medium prior to ICSIOther
| Study group | Role | What they receive |
|---|---|---|
| micoinjection according to classical protocole | Active comparator | incubation of sperm in incubation medium Receives: Other: capacitation in incubation medium prior to ICSI |
| incubation in follicular fluid | Experimental | incubation of sperm in follicular fluid prior to microinjection Receives: Other: Acrosome Reaction induction |
What is being measured
The primary outcome is the main question the study is designed to answer.
number of early pregnancy termination
Measured: 9 months
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted22 Oct 2014 (estimated)
- Study start13 Dec 2014
- Primary completion18 May 2015
- Study completion18 Dec 2015
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (3)Papers the sponsor has linked to this study.
- Other trials for Assisted Reproductive TechniqueStudies of the same condition, open and under way.
- More trials run by Assistance Publique - Hôpitaux de ParisThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Other
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Enrolment
- 111 participants (actual)
Sponsor and investigators
- Lead sponsor
- Assistance Publique - Hôpitaux de Paris
- Sponsor type
- University, hospital or other
- Collaborators
- Agence de La Biomédecine, URC-CIC Paris Descartes Necker Cochin
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT02271490
- Sponsor's protocol ID
- 2011-A01376-35
- Acronym
- RA-ICSI
- Status last verified
- May 2026
- First submitted
- 7 Oct 2014
- Last updated
- 20 May 2026
- Results posted
- No
- Data monitoring committee
- No
Publications
Lacham-Kaplan O, Trounson A. Intracytoplasmic sperm injection in mice: increased fertilization and development to term after induction of the acrosome reaction. Hum Reprod. 1995 Oct;10(10):2642-9. doi: 10.1093/oxfordjournals.humrep.a135760.
PubMed 8567785Roldan ER. Better intracytoplasmic sperm injection without sperm membranes and acrosome. Proc Natl Acad Sci U S A. 2006 Nov 21;103(47):17585-6. doi: 10.1073/pnas.0608752103. Epub 2006 Nov 13. No abstract available.
PubMed 17101960Morozumi K, Shikano T, Miyazaki S, Yanagimachi R. Simultaneous removal of sperm plasma membrane and acrosome before intracytoplasmic sperm injection improves oocyte activation/embryonic development. Proc Natl Acad Sci U S A. 2006 Nov 21;103(47):17661-6. doi: 10.1073/pnas.0608183103. Epub 2006 Nov 7.
PubMed 17090673
Study at a glance
From the registry record, last updated by the sponsor on 20 May 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Improvement of the Post ICSI Pregnancy Outcome by Induction of the Acrosome Reaction Prior to ICSI
- ClinicalTrials.gov ID
- NCT02271490
- Acronym / sponsor ID
- RA-ICSI / 2011-A01376-35
- Keywords
- Assisted Reproductive Technique, ICSI, Acrosome Reaction, Pregnancy outcome
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 111 participants (actual)
- Lead sponsor
- Assistance Publique - Hôpitaux de ParisUniversity, hospital or other
- Collaborators
- Agence de La Biomédecine, URC-CIC Paris Descartes Necker Cochin
- Study start
- 13 Dec 2014 (actual)
- Primary completion
- 18 May 2015 (actual)
- Study completion
- 18 Dec 2015 (actual)
- First posted
- 22 Oct 2014 (estimated)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Introduction To get through the egg vestment and fertilize the oocyte, the spermatozoon uses its acrosomal enzymes. When Intracytoplasmic sperm microinjection (ICSI) is performed, the acrosomal enzymes are introduced with the spermatozoa inside the ooplasme.
The fate of these enzymes, that normally never enter the oocyte, is not known. But they impair the embryo development.
Indeed, although the ICSI outcome is satisfactory in humans, a series of studies in many species (mouse, hamster, cattle, and horse) demonstrate the deleterious effects of the introduction of acrosomal material in the oocyte cytoplasm, on embryo and fetal development. These studies have also shown two things:
- The bigger the acrosome, the more deleterious are the effects of their introduction into the egg.
- And that the induction of the acrosome reaction (AR) prior to ICSI significantly improves embryonic development and the number of babies born after embryo transfer as it is the case in the mouse. The microinjection of acrosome reacted sperm increases from 40 to 70 % the percentage of pups born per embryo transferred.
Hypothesis :
It is possible to improve ICSI outcome, in terms of babies born in human, by induction of the AR prior to microinjection.
After studying several techniques, we choose a physiologic technique for acrosome induction.
The induction of acrosome reaction prior to ICSI should improve in utero fetal development and decrease the rate of miscarriage and pregnancy arrest.
Detailed description
- Introduction Intracytoplasmic sperm microinjection (ICSI) produces 70% of fertilized oocytes and zygotes which mostly develop normally. To perform ICSI, a spermatozoon is taken from a sperm suspension after gradient migration. It is then immobilized by breaking its flagellum using a micropipette, and introduced into the oocyte cytoplasm. The rate of spontaneous acrosome reaction in humans is less than 20 %. Two studies on the percentage of acrosome reacted and immobilized sperm showed that 95% of them have a destabilization of the membrane but only 17.8% of them had made a full RA. In other words, when we microinjected 10 spermatozoa, only 2 of them are completely rid of their acrosome material. All others are introduced into the oocyte with acrosomal material. But this material does not normally enter the oocyte since the acrosome reaction is a prerequisite to the passage of the zona pellucida that surrounds the egg . The importance of using an acrosome-reacted spermatozoon for the success of ICSI has been previously highlighted in several animal species. It has been demonstrated that the induction of the acrosome reaction in mice lead to higher fertilization rates (from 30% to about 60 % ) . It is similar, in the rabbit and horses . Kimura et al. also reported that mouse oocytes injected with acrosome-intact rabbit and hamster sperm exhibited a nuclear activation and cessation of embryonic development without reaching the two-cell stage. This "cytotoxicity" of the same sperm disappears when they are released from their acrosomes before injection. In another study, the detrimental effect on oocyte survival of the presence of the acrosome during the injection of sperm heads was demonstrated in the golden hamster. All oocytes microinjected with acrosome-intact sperm were dead, while only those injected with acrosome reacted sperm have not only survived, but have also developed to the stage of two pronucleus in 79 % of cases and helped to get live births ( 19%). The team of Yanagimachi reported a study on the potentially dangerous effect of the incorporation of the sperm acrosome of different species within mouse oocytes. According to these authors, harmful components would probably be the enzymes such as trypsin-like acrosine and hyaluronidase, since their injection mimicked the effects of ICSI with acrosome-intact sperm. In the same study, it was confirmed that the toxic effects were correlated with the size of the acrosome and therefore the contents of protease enzymes. The toxic effects of the acrosome and its contents have been described explicitly by Morozumi and Yanagimachi. It induces deformation of the oocyte with an irregular appearance, edema or cytolysis with a pseudo-vacuolated cytoplasm appearance. Furthermore, it has been established that the damage caused by exogenous or acrosomales enzymes were correlated with oocyte cytoskeleton disruption through an aberrant accumulation of microtubules in the cortex of the oocyte. In addition to the morphological and ultrastructural alterations in the oocyte, the incorporation of the acrosome may result in a lack of nuclear activation of the oocyte. Kasai et al. reported that the completion of oocyte meiosis occur faster if the sperm was released from the acrosome. Similarly, an increase in fertilization rate after ICSI with acrosome reacted sperm was observed in pigs. The study by Morozumi et al. also demonstrated that the induction of the acrosome reaction of sperm from several species prior to ICSI resulted in an acceleration of oocyte activation, which was manifest in human spermatozoa. This was evidenced by the significant differences between the profiles of calcium oscillations after ICSI with acrosome-intact or acrosome-reacted sperm. Calcium waves recorded in oocytes injected with acrosome-reacted spermatozoa were characterized by an early onset and amplitude and a higher frequency. In contrast, the calcium response was abnormally delayed in oocytes injected with acrosome-intact sperm. Thus, altered calcium oscillations, the "key" oocyte activation signals during ICSI, is the cause of abnormal pre-implantation embryo development to the blastocyst stage. Indeed, the proportion of live healthy mice births is increased from 40% to 71%, when intact or acrosome-reacted sperm are microinjected, respectively . These same studies have also shown two things:
- The introduction of acrosomal material is more harmful when the quantity is large compared to the oocyte volume. There is therefore interest in systematically reducing the amount of material introduced into the oocyte cytoplasm to improve embryonic development.
- The second thing is that the induction of the acrosome reaction before ICSI greatly improves embryonic development and therefore the number of babies born from embryo transfer. Although ICSI in human gives very satisfactory results, the rate of infants obtained by embryo is lower than after IVF embryos transfer. Hence, there is a possibility of improving the results of ICSI by induction of the acrosome reaction prior to microinjection. After several studies we used incubation of spermatozoa with the follicular fluid (FF) of the partner to induce the spermatozoa acrosome reaction (Karim Rahal, 2011 Master Thesis 2). FF is indeed a potent inducer of the AR. There is no problem of traceability since the FF of the patient is used only for the sperm of her husband. This technic can be applied to the poorest semen. Finally, the technique is used in a very easy routine, since the follicular fluid is always recovered during oocyte retrieval and thus available.
- Hypothesis A preliminary study was run in human on microinjection of spermatozoa that were selected for their acrosomal status by birefringence microscopy. It showed that it improves the implantation rate from 24,4 % to 39 % . We therefore hypothesize that the improvement in the implantation rate of embryos obtained by ICSI after acrosomal induction as well as the reduction of miscarriage rate may result in improved clinical pregnancy outcome and birth rates of about 10 %.
Study design
- Primary purpose
- Other
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| micoinjection according to classical protocole | Active comparator | Other: capacitation in incubation medium prior to ICSIincubation of sperm in incubation medium |
| incubation in follicular fluid | Experimental | Other: Acrosome Reaction inductionincubation of sperm in follicular fluid prior to microinjection |
Who may qualify
- Ages
- 18 to 43 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult
Key inclusion criteria (3 listed)
- Couples involved in an ICSI program
- First attempt only
- Cohort with at least 6 oocytes
Key exclusion criteria (3 listed)
- No social security number
- No signed consent form
- Surgically retrieved sperm
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Acrosome Reaction induction | Other | incubation in follicular fluid |
| capacitation in incubation medium prior to ICSI | Other | micoinjection according to classical protocole |
Primary outcome
number of early pregnancy termination
Time frame: 9 months
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 20 May 2026.
- Background: PubMed 8567785Lacham-Kaplan O, Trounson A. Intracytoplasmic sperm injection in mice: increased fertilization and development to term after induction of the acrosome reaction. Hum Reprod. 1995 Oct;10(10):2642-9. doi: 10.1093/oxfordjournals.humrep.a135760.
- Background: PubMed 17101960Roldan ER. Better intracytoplasmic sperm injection without sperm membranes and acrosome. Proc Natl Acad Sci U S A. 2006 Nov 21;103(47):17585-6. doi: 10.1073/pnas.0608752103. Epub 2006 Nov 13. No abstract available.
- Background: PubMed 17090673Morozumi K, Shikano T, Miyazaki S, Yanagimachi R. Simultaneous removal of sperm plasma membrane and acrosome before intracytoplasmic sperm injection improves oocyte activation/embryonic development. Proc Natl Acad Sci U S A. 2006 Nov 21;103(47):17661-6. doi: 10.1073/pnas.0608183103. Epub 2006 Nov 7.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Acrosome Reaction induction and capacitation in incubation medium prior to ICSI in people with Assisted Reproductive Technique and ICSI, run by Assistance Publique - Hôpitaux de Paris at 1 site in France.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 3 inclusion and 3 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 20 May 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in France. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
number of early pregnancy termination (time frame: 9 months). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT02271490, which also lists 3 linked publications.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 20 May 2026.