What is Mini IVF and How Does it Differ from Natural IVF?

One of the most important steps in achieving great results during an In Vitro Fertilization (IVF) cycle  is having a sufficient number of mature eggs. For this reason it is essential to stimulate the function of the ovaries and, contrary to what happens in a natural cycle, to try to obtain an adequate number of oocytes.

Ovarian stimulation is based on follicle-stimulating hormones (FSH), combined with other fertility drugs and injections whose daily dose varies from 150 to 300 IU per day. This treatment lasts 8 to 14 days, ovaries produce 7 to 15 follicles as a result.

Although it is the most important step of the IVF journey, it is not free from complications. If not monitored thoroughly, ovarian stimulation may cause a condition, called ovarian hyperstimulation syndrome (OHSS), where ovaries become swollen and painful.

The risk of OHSS, the fact that it requires medications for 14 days, and the costs associated with it have pushed scientists to come up with an alternative solution for ovarian stimulation.

What is mini IVF?

Mini IVF is a type of in vitro fertilization method that simplifies the step of ovarian stimulation by reducing the hormone medication dose in a cycle of conventional IVF treatment. There are many different names apart from mini IVF for this procedure: Minimal stimulation IVF, mild IVF, soft IVF, gentle IVF or IVF Lite.

The aim of the mini IVF is to make the ovarian stimulation procedure more comfortable, less expensive and with fewer side effects and even eliminate injections. However, this slight stimulation of the ovaries eventually decreases the final number of oocytes, which may possibly decrease the pregnancy rates. To overcome this problem, another method of IVF, intracytoplasmic sperm injection (ICSI) is applied.

ICSI is basically the direct injection of a single, selected sperm to an egg. Under normal conditions, a sperm sample is introduced into a petri dish with mature eggs, and let to be fertilized randomly by a sperm in the sample. By applying ICSI, your embryologist ensures that the limited number of eggs retrieved are all fertilized.

Although ICSI doesn’t significantly increase the number of live births, it makes sure that eggs are indeed fertilized.

According to a 2018 study, egg retrieval of up to 11 oocytes is effective in increasing the live birth rates, but 18 or more oocytes significantly increased the risk of developing OHSS and unwanted side effects associated with it.

This study reveals the logic behind the development of minimal stimulation IVF. The more doesn’t necessarily mean the better. Physiological challenges that are put on a woman undergoing IVF should be carefully considered, and unnecessary or excessive drug use should be eliminated.

When can Mini IVF be Applied?

Mini IVF is an alternative method of IVF to eliminate the possibility of developing OHSS and its unwanted effects. During mini IVF, ovaries are stimulated less and therefore a limited number of eggs are produced. Decrease in the number of oocytes can be challenging for candidate parents, especially if they’re suffering from a serious fertility condition. Therefore, applicability of mini IVF should be carefully evaluated for each couple.

Mini IVF can be considered when following conditions apply:

• Patients below maternal age, which is 35, with a healthy ovarian function.

• Patients above maternal age or those with poor ovarian reserve. When a patient consistently produces a low number of oocytes (below three to four), regardless of the intensity of stimulation, it is possible to forgo the use of hormone medications.

• Patients that are under risk of ovarian hyperstimulation syndrome.

• When the patient does not want there to be any leftover embryos after transfer for moral or spiritual grounds.

What is the process of Mini IVF? How Does it Differ from Conventional IVF?

Minimal stimulation IVF has a very similar procedure with conventional IVF cycle. Until ovulation stimulation is initiated, patients use oral contraceptives. Then, she will switch to oral fertility drugs at a lesser dose rather than continue with injectable fertility medications to stimulate ovulation.

The development of the follicles into eggs should be carefully monitored to ensure that the dosage of the fertility drugs is enough and there is no problem with the egg development. Mini-IVF patients will still have to inject themselves, but they will do it less frequently and with smaller amounts than those undergoing traditional IVF. Before egg collection, a combination of follicle-stimulating hormone (FSH) and human chorionic gonadotropin (hCG) will be injected.

After egg retrieval, the eggs will be fertilized with the sperm of the male partner or a sperm donor, grown into embryos under lab conditions, and then implanted into the female partner’s uterus.

The Advantages of Mini IVF

For young women below maternal age and with a good ovarian function, the success rate of mild IVF is comparable to natural IVF and offer great benefits:

• The risk of developing OHSS is less

• The total dosage of fertility drugs is less, making it less costly and therefore more accessible

• The number of visits are less

• The possible side effects will be greatly reduced

• Less emotional stress due to hormonal therapy

The Disadvantages of Mini IVF

Soft IVF is not a procedure for every woman. It is not commonly advised if a woman has a low ovarian reserve or above maternal age because,

• Fewer oocytes are collected as a result of low stimulation and, therefore, the pregnancy success rate could be lower

• Fewer number of oocytes also decrease the possibility of embryo preservation for future courses of treatment

However, it should be noted that intracytoplasmic sperm injection (ICSI), also called microinjection, can be applied to secure the possibility of fertilization. Even though ICSI doesn’t end up with a 100% fertilization success rate, it ensures that the embryo is fertilized with one selected, healthy sperm.