Mild ovarian stimulation, also known as mini IVF, mild IVF and gentle IVF, is a protocol used in in vitro fertilization (IVF) treatments. Basically, mini-IVF consists of using lower doses of hormone medication. This protocol manages to reduce the adverse effects of ovarian stimulation and improve the quality of the eggs obtained.
This is an alternative to standard IVF that is indicated for various types of patients, including women over 40. In addition, mini-IVF can be the recommended fertility treatment for couples with a mild male factor.
Another of the advantages of mini IVF is that it allows the price of assisted reproduction techniques to be reduced without affecting negatively the results for achieving pregnancy. All this means that many clinics have opted for this type of gentle ovarian stimulation in recent years.
Below you have an index with the 9 points we are going to deal with in this article.
What is a mini IVF?
Ovarian stimulation consists of controlling the function of the ovaries by administering hormones. Its purpose is to obtain a greater quantity of eggs in assisted reproduction treatments than naturally.
Generally, the hormonal stimulation of the ovaries is based on the use of two types of drugs:
- Gonadotropins (FSH, LH) to increase the growth of the ovarian follicles.
- GnRH analogues to control physiological hormone secretions.
Traditionally, it was thought that the more eggs obtained through this stimulation, the more likely the fertility treatment was to succeed. Today, it is known that this is not the case thanks to several studies.
Mini IVF treatment is a reproductive option similar to conventional IVF, with a single difference in the ovarian stimulation phase. Their aim is to obtain fewer, but high-quality eggs.
What effects does hormone stimulation have?
Several studies have shown that with high doses of medication, there are more chromosomally abnormal embryos. Therefore, obtaining a greater number of eggs is not always synonymous with ensuring the success of the treatment.
It should also be taken into account that the phase of hormone stimulation is one of the riskiest for patients. The reason is that if ovarian stimulation is not performed properly, it can trigger ovarian hyperstimulation syndrome.
Furthermore, if the ovarian stimulation is very strong, the quality of the endometrium is also worsened, so the chances of getting an embryo to implant in a fresh cycle are also diminished. This occurs because endometrial receptivity is altered.
For all these reasons, the current trend is to reduce as much as possible the hormonal doses in the ovarian stimulation treatments to avoid any possible harmful effects.
Mild stimulation protocols consist of administering lower doses of hormones and/or for fewer days to avoid the side effects of the drugs but without reducing the chances of successful treatment.
By means of these protocols, a smaller number of eggs is obtained. However, thanks to the better quality of these and the optimization of the assisted reproduction techniques, the results do not have to be altered.
For which patients is this protocol recommended?
Despite the benefits of this treatment, mini-IVF is not indicated for all patients. Women who have a good ovarian reserve and a very good prognosis are candidates for mild IVF, as this reduces the possible adverse effects that hyperstimulation can cause.
The following are some of the patients who are susceptible to mild ovarian stimulation:
- Women with previous ovarian hyperstimulation syndrome or at high risk of suffering from it.
- Women under 35 with a short history of infertility.
- Patients with functional problems in the fallopian tubes, but not in the ovaries.
- Couples with mild to moderate male factor problems.
- Single women or couples of women with no associated gynecological problem.
- Patients who, for moral or religious reasons, do not want leftover embryos.
In addition, a gentle ovarian stimulation is also used in patients with low ovarian reserve or poor egg quality, as this improves the quality of the eggs obtained by performing more physiological stimulation.
Considering undergoing a fertility treatment? By getting your individual Fertility Report your will see different clinics especially selected for you out of the pool of clinics that meet our strict quality criteria. Moreover, it will offer you a comparison between the fees and conditions each clinic offers in order for you to make a well informed choice.
It should be noted that the application of this gentle stimulation protocol in patients where it is not indicated can seriously compromise the chances of successful fertility treatment.
The steps to follow to carry out a cycle with a mild ovarian stimulation are very similar to those of a conventional stimulation. The only difference is that the start of the stimulation is delayed, usually to day 5 of the cycle, and starts with moderate doses of gonadotropins (150 IU of FSH).
These protocols are made possible by the emergence of GnRH antagonists, since if they were performed with GnRH agonists, more days of treatment would be required. The administration of the antagonists can be started on day 6 of the cycle or when there is a follicle larger than 14 mm.
Throughout this period of time, the patient will attend various ultrasound controls to assess the size of the follicles. Once it reaches a size of 16-18 mm, ovulation will be induced and the ovarian puncture will be performed to obtain the eggs. With these protocols, a maximum of 8 eggs are expected to be obtained.
The following steps will be identical to any other IVF cycle. Those mature eggs will be fertilized in the laboratory and the best quality embryo(s) will be transferred.
Advantages of mini IVF
By using mild doses of gonadotropins, the duration and cost of the medication are reduced, as well as the side effects produced by high doses of hormones.
In addition, as better quality embryos are obtained, more transfers of a single embryo can be made with a high probability of success. This leads to a reduction in the rate of multiple gestations, which causes complications for both mother and fetus.
Endometrial receptivity also shows benefits. Mini IVF is a more physiological process, so endometrial receptivity is not as altered as in conventional ovarian stimulation cycles.
Reducing the duration of the stimulation and its effects also improves emotional stress. This makes the gentle ovarian stimulation less psychologically demanding and therefore decreases the treatment drop-out rate.
Disadvantages of mini IVF
Although opinions on this technique are generally positive, both among patients and specialists, gentle IVF also has a number of drawbacks.
The main drawbacks of this protocol are the consequence of obtaining fewer eggs and, therefore, fewer embryos than in conventional treatments. For this reason, the following cases can occur:
- Higher probability of not having good quality embryos for transfer.
- Less probability of having good quality leftover embryos to vitrify and be able to use them in future transfers.
- Possibility of needing more ovarian stimulation cycles to get pregnant.
In addition, there is an increased risk that the ovaries may not respond as well as expected and the cycle may have to be canceled or eggs may not be found when the follicular puncture is performed because of the mild ovarian stimulation.
FAQs from users
Does mini IVF work for women over 37 years?
Of course. In fact, it is one of the indications for In vitro fertilization with minimal stimulation, which seeks to improve ovarian quality.
However, each clinical case must be studied, evaluating its intrinsic characteristics in consultation with a specialist doctor who will advise you on the treatment that offers the greatest chance of success.
Does the mini IVF have a high success rate?
It is an IVF in natural cycle or minimal ovarian stimulation in order to obtain a few oocytes that will be fertilized in the laboratory by IVF or ICSI.
Logically, since fewer oocytes can be obtained and each oocyte has the possibility of being fertilized and giving rise to a viable embryo (not all oocytes are fertilized and not all embryos evolve), the possibilities of pregnancy are less than in an IVF with a good number of oocytes (between 5 and 12 oocytes would be an ideal number).
However, in specific cases, your doctor may recommend this type of treatment, especially when there is not a good response to ovarian stimulation and even with high doses of medication.
The rate of gestation will depend largely on the patient's age. The younger the patient is, the better the chances of pregnancy.
How many eggs are obtained with gentle stimulation?
With this type of stimulation, between 2 and 5 oocytes are expected, at most 8. However, it must be taken into account that the number of oocytes obtained in each cycle does not depend only on the protocol used, since each woman responds differently to these treatments. Therefore, it is not possible to know the exact number.
Suggested for you
The main difference between IVF and mini-IVF is in the process of ovarian stimulation. If you want to learn more about this step of fertility treatment, you can visit the following article: What is Ovarian Stimulation - Process, Medications, and Symptoms.
Besides, if pregnancy is not achieved after several IVF cycles due to low ovarian reserve, another alternative would be to switch to egg donation. We recommend you access this link for more in-depth information: Donor-Egg IVF Procedure for Recipients - Protocol & Cost.
Our editors have made great efforts to create this content for you. By sharing this post, you are helping us to keep ourselves motivated to work even harder.
Ferraretti AP, La Marca A, Fauser BCJM, Tarlatzis B, Nargund G, Gianaroli L, ESHRE. ESHRE consensus on the definition of 'poor response' to ovarian stimulation for in vitro fertilization: the Bologna criteria. Hum Reprod. 2011 Jul;26(7):1616-24. doi: 10.1093/humrep/der092. Epub 2011 Apr 19.
M Zarek S, Muasher S. Mild/minimal stimulation for in vitro fertilization: an old idea that needs to be revisited. Fertil Steril. 2011 Jun 30;95(8):2449-55. doi: 10.1016/j.fertnstert.2011.04.041. Epub 2011 May 7.
Nargund G, Kumar Datta A, Fauser B. Mild stimulation for in vitro fertilization. Fertil Steril. 2017 Oct;108(4):558-567. doi: 10.1016/j.fertnstert.2017.08.022.
Reed BG, L Wu J, Bou Nemer L, Carr B, Bukulmez O. Use of Clomiphene Citrate in minimal stimulation in vitro fertilization negatively impacts endometrial thickness: an argument for a freeze-all approach. JBRA Assist Reprod. 2018 Nov 1;22(4):355-362. doi: 10.5935/1518-0557.20180070.
Shrestha D, La X, L Feng H. Comparison of different stimulation protocols used in in vitro fertilization: a review. Ann Transl Med. 2015 Jun;3(10):137. doi: 10.3978/j.issn.2305-5839.2015.04.09.
Zhang J, Yang M, Merhi Z. Efficiency of metaphase II oocytes following minimal/mild ovarian stimulation in vitro fertilization. Fertil Res Pract. 2016 Sep 1;2:2. doi: 10.1186/s40738-016-0025-6. eCollection 2016.