Young couple using laptop computer to research fertility treatments in their kitchen.
There’s buzz around different, perhaps less expensive, versions of IVF. Maybe if you need IVF, you can choose a more natural, cheaper version and still be successful? Maybe.
Let’s look at the different versions, their benefits and potential drawbacks.
What is Mild IVF?
Mild IVF works around your natural menstrual cycle, although it requires some hormonal stimulation to produce 2-10 eggs. The dosage of medication during Mild IVF is lower than during conventional IVF. Because the medication taken to overstimulate ovarian production of eggs is part of the high cost of IVF, taking less of it can be a cost a savings. Plus, less stimulation can reduce the risk of painful overstimulation known as Ovarian Hyperstimulation Syndrome (OHSS) which can be caused by FSH injections.
Drawback of Mild IVF. Fewer eggs are collected. Eggs are fragile and not all of them will mature properly or fertilize. With fewer eggs, fewer embryos are formed, and there will be fewer embryos to transfer. If multiple cycles are required, the treatment could become more expensive than conventional IVF.
What is Natural IVF?
Natural IVF uses a woman’s natural menstrual cycle without the use of medicine to stimulate egg production. Without stimulation, a woman will produce only one egg follicle that may ripen into a mature healthy egg. Patients are monitored with ultrasounds and bloodwork (same as regular IVF) to track the development of the single ovarian follicle so that it does not release (ovulate) by the body before it can be retrieved.
The patient then undergoes the same type of egg retrieval that is done during standard IVF to retrieve the egg from the single follicle. If the egg retrieval is successful, an attempt is made to fertilize the egg in the laboratory. If a viable embryo develops, a physician will transfer it back into her uterus. Eggs are fragile and mature eggs retrieved do not always fertilize even under the best lab supervision which is why traditional IVF and egg freezing procedures aim to collect 15-20 eggs.
Drawback. With only one egg available, this process has low success rates. Natural IVF can be just as stressful as traditional IVF and the costs can add up if done multiple times.
Traditional IVF can use a Fresh or Frozen Cycle
Fresh Cycle Traditional IVF
Regular IVF cycles are often referred to as either ‘fresh’ or ‘frozen’ cycles. During a fresh cycle a woman’s ovaries are stimulated with medication to produce multiple mature egg follicles. The patient is monitored closely with multiple ultrasound appointments. Her eggs are retrieved, fertilized, and the zygote (ZYE-goat) or fertilized eggs that begin to divide to form embryos are transferred into her uterus during the same cycle. Clinics that use fresh cycles will often transfer 2 or even 3 embryos in the hope that one of them will implant and grow into a healthy, viable fetus.
Drawback. The cost can be high and success rates of fresh cycles often depend on transferring 2 or more embryos which can lead to multiples. Twin and especially triplets are high-risk pregnancies that can lead to long-term complications for both the mother and the fetuses.
Frozen Cycle Traditional IVF
Frozen cycles can have a longer timeline as the process of egg retrieval and embryo transfer happen during different months or menstrual cycles. Implantation rates improve with a delayed transfer as the lining of the uterus can be brought to optimal conditions for carrying a healthy baby to term.
Similar to the fresh cycles, the woman’s ovaries are stimulated to produce multiple mature follicles and her eggs are retrieved and fertilized in the lab. The embryos may be grown to days 5-7.
The resulting embryos are then flash frozen in a process called vitrification. Embryos do well with the freezing-thawing process, with >97% of embryos surviving vitrification and thaw.
Before freezing, some clinics will take a biopsy of each embryo and send it to a genetic lab for testing. PGT-A (Preimplantation Genetic Testing for Aneuploidies) allows the selection of genetically normal embryos for transfer, ruling out Down Syndrome, increasing implantation rates, and reducing miscarriage rates. The genetic information helps determine which embryo to transfer and give confidence to only transfer one embryo at a time for a safer pregnancy with a high chance of success. If additional embryos are viable, they are kept frozen to use at a later date.
Drawback. The cost can be higher although prices vary from clinic to clinic. Plus the genetic lab fees may be an additional expense. However, higher success rates may prove to be a cost savings as this method may require less time and money to achieve the desired result of a child.
IVF Success Rates
It is important to note that none of these IVF processes are 100% guaranteed. Even using the traditional course of egg follicle stimulating drugs may not result in enough eggs to fertilize successfully and egg donors or sperm donors are often needed. Every patient is unique. However frozen cycles of traditional IVF with PGT-A are the most successful at achieving a live birth. Knowing the chromosomes are correct before transfer can limit early miscarriages and rule out genetic abnormalities. Plus, frozen cycles may result in additional embryos to transfer at a future date so patients may try again or come back for a second child.
