The first successful IVF in 1978 in England was conducted in a natural cycle, requiring extensive diagnostic examinations. To make IVF more practical and successful, this approach was later replaced by hormonal stimulation therapy. However, in recent years, there has been a renewed interest in non-classical IVF treatments, such as Natural Cycle IVF (NC-IVF) and Minimal Stimulation IVF. Today, we provide an insight into Natural Cycle IVF as an alternative to conventional IVF.
Treatment Concept
Natural Cycle IVF is a gentle reproductive medicine approach that aims to retrieve the naturally matured egg of the treatment cycle, fertilize it outside the body, and transfer it back into the uterus two days later. The idea behind this method is that without external hormonal interference, egg maturation occurs optimally, providing a strong foundation for a successful pregnancy.
Procedure
NC-IVF follows the natural rhythm of a woman’s cycle with minimal or no hormonal intervention. This requires precise cycle monitoring through ultrasounds and hormone tests to determine the exact moment for egg retrieval before natural ovulation occurs.
Once retrieved, the egg is fertilized in the lab and cultured in an incubator until it is ready for transfer into the uterus. Two treatment options exist:
- Natural Cycle IVF: No medications are used. Ultrasounds and hormonal analyses closely monitor follicular development until ovulation is imminent, at which point egg retrieval is performed. The downside is that frequent medical check-ups are required to pinpoint ovulation timing.
- Modified Natural Cycle IVF: A small dose of FSH is administered to gently stimulate the ovaries. Additionally, medication is used to prevent spontaneous ovulation. When a mature follicle is present, ovulation is triggered by an injection.
Who Is a Candidate for Natural Cycle IVF?
NC-IVF is recommended for:
✔️ Women with regular cycles (23–33 days)
✔️ Women under 40 years old
✔️ Women who wish to avoid hormone treatments
✔️ Women with low ovarian reserve
✔️ Women for whom conventional IVF has failed
It is not recommended for women who:
❌ Are over 39 years old
❌ Have irregular cycles or late ovulations
How Can OvulaRing Support Natural Cycle IVF?
OvulaRing is an innovative cycle and fertility diagnostic tool (Cyclofertilography) that helps monitor both pre-treatment cycles and the treatment cycle itself.
Since NC-IVF requires frequent monitoring, OvulaRing:
✔️ Reduces the need for time-consuming and costly check-ups
✔️ Provides continuous tracking of ovulation timing
✔️ Allows for personalized stimulation protocols
✔️ Optimizes the timing of egg retrieval
By considering not just the current cycle but also previous cycles, OvulaRing enhances treatment efficiency, reducing both costs and side effects.
Benefits of Natural Cycle IVF
✔️ Avoids complications from high-dose hormone stimulation
✔️ Eliminates the risk of Ovarian Hyperstimulation Syndrome (OHSS)
✔️ Reduces the likelihood of multiple pregnancies and preterm birth
✔️ No general anesthesia required—local anesthesia is sufficient for egg retrieval
✔️ Higher egg quality and better uterine lining conditions for implantation
✔️ Lower treatment costs (though over a longer treatment period)
✔️ More effective for low responders (women whose ovaries do not respond well to high-dose hormone therapy)
📌 Studies indicate:
✔️ Low-dose stimulation leads to better pregnancy rates in low responders (Youssef 2017)
✔️ High-dose stimulation increases genetic abnormalities in eggs (Baart 2007)
✔️ Excessive hormone levels negatively impact uterine lining quality (Qiu-Ju 2007)
Since Natural Cycle IVF is safer and less invasive, monthly treatments can be conducted, making each cycle more affordable (von Wolff 2020).
Drawbacks of Natural Cycle IVF
❌ Lower success rate per cycle (about 10% vs. 25% for conventional IVF) (von Wolff 2020)
❌ Only one egg is retrieved per cycle, reducing the chances of fertilization
❌ Not every retrieved egg is successfully fertilized
❌ Requires a healthy hormone balance and regular cycles
📌 German health insurance policies currently favor conventional IVF over non-classical IVF methods. Given the advantages of Natural Cycle IVF, an updated reimbursement model that covers treatment costs rather than the number of cycles would be more appropriate (von Wolff 2020).
Conclusion
Natural Cycle IVF is a well-established and gentle alternative to conventional IVF for treating infertility.
✔️ Consult your gynecologist to determine if NC-IVF is right for you.
✔️ Find fertility centers near you that offer this method.
✔️ Consider OvulaRing for better cycle diagnostics and cost-effective treatment.
References
https://barcelonaivf.com/de/blog/allgemaine-informationen/was-bedeutet-natuerliche-in-vitro-fertilisation Zugriff: 29.10.20
Baart EB et al. 2007. Milder ovarian stimulation for in-vitro fertilization reduces aneuploidy in the human preimplantation embryo: a randomized controlled trial, Human Reproduction, Volume 22, Issue 4: 980–988. https://doi.org/10.1093/humrep/del484
IVF im natürlichen Zyklus: künstliche Befruchtung ohne Hormone. https://www.wunschkinder.net/aktuell/wissenschaft/ivf-und-icsi/ivf-im-natuerlichen-zyklus-kuenstliche-befruchtung-ohne-hormone-7732/ Zugriff. 29.10.20
Uniklinikum Dresden. https://www.uniklinikum-dresden.de/de/das-klinikum/kliniken-polikliniken-institute/gyn/patienten-einweiser/Sprechstunden/kinderwunschsprechstunde/ivf-icsi-im-naturlichen-zyklus Zugriff: 29.10.20
