What is happening in Marseille
In May 2026, Saint Joseph Hospital in Marseille announced the launch of the OPKAPAMIV project — a French first in fertility care for PCOS/PMOS patients. It is the first centre in France to formally deploy CAPA-IVM (CAPAcitation + In Vitro Maturation) within an official clinical research protocol for women with polycystic ovary syndrome.
The technique is being developed at the Centre Sainte-Colette (Department of Reproductive Medicine and Biology, 172 rue du Rouet — 13008 Marseille), one of France's most active ART centres and a pioneer in oocyte vitrification since 2011.
OPKAPAMIV — funding
Conseil Départemental des Bouches-du-Rhône · Ferring Pharmaceuticals · Densore Laboratories
International collaboration: Brussels IVF (UZ Brussels, Belgium) · My Duc Hospital (Ho Chi Minh City, Vietnam)
Why conventional IVF is risky for PCOS/PMOS patients
Conventional IVF relies on intensive ovarian stimulation through gonadotrophin injections over 10 to 14 days. For most patients, this protocol is well tolerated. For PCOS/PMOS patients, it carries a specific and serious risk: ovarian hyperstimulation syndrome (OHSS).
The ovaries of a woman with PCOS contain a much higher density of small resting follicles — reflected by the characteristically elevated AMH. Under intensive hormonal stimulation, these follicles respond en masse: the ovaries swell, fluid accumulates in the abdomen and sometimes the thorax. In severe cases, OHSS causes intense abdominal pain, breathing difficulties, and a risk of venous thrombosis.
This is precisely the risk CAPA-IVM targets: by retrieving oocytes before any intensive stimulation, the dangerous hormonal cascade is short-circuited from the outset.
How CAPA-IVM works: the two phases
CAPA-IVM is a two-step in vitro maturation technique, developed in collaboration between Brussels IVF (UZ Brussels) and My Duc Hospital in Vietnam.
Phase 1 — Pre-maturation (capacitation) · 24 hours
Immature oocytes, retrieved by follicle aspiration after a minimal preparation (1–3 injections instead of 10–14), are placed in a medium enriched with CNP — C-type natriuretic peptide. CNP holds the oocytes in a controlled "pause" that prevents premature maturation and improves their cytological and chromosomal quality. This capacitation phase is what distinguishes CAPA-IVM from earlier, simpler IVM techniques.
Phase 2 — Final maturation · 30 hours
The pre-matured oocytes are transferred into a standard maturation medium supplemented with FSH and amphiregulin. They complete their in vitro maturation, reaching the MII stage required for fertilisation. Mature oocytes are then vitrified (ultra-rapid freezing, mastered at Centre Sainte-Colette since 2011). At the transfer cycle, the oocyte is thawed, fertilised by ICSI, and the embryo transferred after endometrial preparation.
| Criterion | CAPA-IVM | Conventional IVF |
|---|---|---|
| Hormone injections | 1–3 | 10–14 (over 2 weeks) |
| OHSS risk | Near zero | High in PCOS patients |
| Hospital visits | Reduced | Very frequent |
| Cumulative live birth rate (24 months) | 38.5% | Variable by protocol |
| Oocyte maturation rate | 63.2% | — |
| Efficacy gap (pronounced PCOS, high AMH) | < 10% vs IVF | Reference |
Sources: Pham et al. JARG 2023 · Human Reproduction (UZ Brussels) Feb. 2024 · 1,707 PCOS patients
What the evidence shows
CAPA-IVM is not an unproven emerging technique — it has a decade of development and several published peer-reviewed cohorts behind it.
- 2020 (JARG) — First live births after CAPA-IVM in PCOS patients (My Duc Hospital, Vietnam). Proof of concept.
- 2023 (JARG) — Cumulative live birth rate after CAPA-IVM : 38.5% over 24 months, oocyte maturation rate 63.2%. Pham HH et al.
- 2024 (Human Reproduction / ESHRE) — Comparative IVM vs IVF study on 1,707 PCOS patients at Brussels IVF : comparable efficacy for pronounced PCOS, markedly superior safety profile.
- 2025 (Reproductive Medicine and Biology) — Reference review on CAPA-IVM toward hormone-free ART (Smitz et al.).
What this concretely changes for PCOS/PMOS patients
For a PCOS/PMOS patient who needs to consider ART, CAPA-IVM represents a paradigm shift on three fronts:
- Safety: OHSS — the most feared complication of IVF in PCOS — is virtually eliminated. This is not a risk reduction; it is the removal of the mechanism that causes it.
- Physical and emotional burden: 1–3 injections instead of two weeks of stimulation, fewer monitoring visits. For women often already exhausted by months or years of diagnostic delay, this is a meaningful difference in how the process is experienced.
- Comparable efficacy: for patients with pronounced PCOS (very high AMH, high AFC), the 2024 study on 1,707 patients shows a non-significant gap versus conventional IVF. CAPA-IVM is therefore not a "safer but less effective backup" — it is an equivalent alternative with a better safety profile.
Limitations and caveats
Despite these promising results, several points deserve honest mention:
- Overall live birth rates remain lower than IVF for patients without PCOS or with a less favourable ovarian profile. CAPA-IVM is particularly relevant specifically for the PCOS phenotype.
- The number of European centres with the technique remains limited. In Marseille, the OPKAPAMIV project is a clinical research framework — inclusion criteria are strict and defined by the medical team.
- As with any ART technique, no outcome can be guaranteed. Published rates are cohort data, not individual promises.
Choosing CAPA-IVM over conventional IVF is a personalised medical decision to discuss with a specialist team, based on your profile (AMH, AFC, age, history).
How to contact Centre Sainte-Colette in Marseille
Centre Sainte-Colette at Saint Joseph Hospital (172 rue du Rouet, 13008 Marseille) is currently the only French centre participating in the OPKAPAMIV project. To find out whether you are eligible, contact their Reproductive Medicine and Biology department directly. The official announcement is available on the Saint Joseph Hospital website (in French).
This page will be updated as results from the OPKAPAMIV project are published.
Frequently asked questions
What is CAPA-IVM and how is it different from conventional IVF?
CAPA-IVM (CAPAcitation + In Vitro Maturation) is an ART technique that retrieves immature oocytes directly from the ovaries without prior intensive hormonal stimulation. The oocytes undergo a 24-hour pre-maturation phase in a medium enriched with CNP (C-type natriuretic peptide), which pauses premature maturation and improves quality, then a 30-hour standard maturation phase. Mature oocytes are then vitrified for a later ICSI/IVF cycle. The key difference from conventional IVF: no 2-week gonadotrophin injection course, so virtually no risk of ovarian hyperstimulation syndrome (OHSS).
Who is CAPA-IVM suitable for?
CAPA-IVM is particularly indicated for PCOS/PMOS patients, who face the highest risk of OHSS during conventional IVF. Patients with very high AMH or a high antral follicle count (AFC) are also strong candidates. Inclusion in the OPKAPAMIV programme in Marseille is subject to specific medical eligibility criteria determined by the Centre Sainte-Colette team.
What are the success rates of CAPA-IVM?
Based on published data from My Duc Hospital (Vietnam) and Brussels IVF (Belgium), which have the largest published series, the cumulative live birth rate after CAPA-IVM is 38.5% over 24 months, with an oocyte maturation rate of 63.2%. A comparative study published in Human Reproduction in February 2024 (1,707 PCOS patients at UZ Brussels) showed that for PCOS patients with pronounced syndrome (high AMH), the gap versus conventional IVF is less than 10% and statistically non-significant — with a markedly better safety profile.
What is ovarian hyperstimulation syndrome (OHSS) and why is it particularly dangerous in PCOS?
OHSS is a complication of hormonal ovarian stimulation in IVF. Over-stimulated ovaries swell and release fluid into the abdomen. Severe forms involve abdominal pain, breathing difficulties, and a risk of venous thrombosis. PCOS patients are particularly at risk because their ovaries contain a high density of follicles that can respond massively to gonadotrophins. CAPA-IVM eliminates this risk by retrieving oocytes before any intensive stimulation.
What does a CAPA-IVM cycle look like in practice?
The protocol is far less demanding than conventional IVF. After a short preparation (1–3 injections instead of 10–14), an oocyte retrieval is performed to collect immature eggs. In the laboratory, they spend 24 hours in a pre-maturation medium (CNP), then 30 hours in a final maturation medium. Mature oocytes are vitrified. At the transfer cycle, the endometrium is prepared, the oocyte thawed, fertilised by ICSI, and the embryo transferred. The number of hospital visits is significantly reduced compared to a standard IVF cycle.
Is CAPA-IVM covered by French national health insurance?
Within the OPKAPAMIV clinical research project, coverage conditions are defined by the study protocol. Interested patients should contact Centre Sainte-Colette at Saint Joseph Hospital in Marseille directly to enquire about inclusion criteria, eligibility, and reimbursement under their specific situation.
Sources
- Saint Joseph Hospital Marseille — OPKAPAMIV launch announcement
- Pham HH et al. — Cumulative live birth rate after CAPA-IVM in PCOS/high AFC — JARG 2023
- Live births after oocyte IVM with prematuration step in PCOS — PMC/JARG 2020
- Brussels IVF (UZ Brussels) — IVM as effective as IVF for PCOS, Human Reproduction Feb. 2024
- Smitz et al. — Human oocyte capacitation culture: toward hormone-free ART — Reprod Med Biol 2025
This page is based on publicly available sources and peer-reviewed publications. It is not intended to recommend a treatment or replace the advice of your medical team.