There are some in vitro fertilization clinics in the US that market aggressively for mini-IVF or micro IVF (also called mild or minimal stimulation in vitro fertilization). Some claims regarding the benefits of mini-IVF are exaggerated or completely untrue. This post clarifies some issues regarding standard vs. mini IVF.
Mild IVF (or micro, or mini IVF) seems to be slowly growing in popularity over the last few years. Is it a good fertility treatment?
- The basic concept is to do in vitro fertilization after a low level of ovarian stimulation with oral medications (possibly with some “low dose” injectables as well).
- This is in contrast to the usual method of ovarian stimulation for IVF which involves more aggressive stimulation of the ovaries with multiple injections over about 8 to 15 days.
- The standard method of stimulating is done in order to try to get about 10 or more eggs to work with for in vitro fertilization.
- The IVF cycle cost for mild IVF (including medications and everything) should be less than the total cost for standard in vitro fertilization
- However, the success rates for standard IVF are much higher
- Success rates with mild in vitro fertilization are much lower – often in the range of about 5% to 15% per attempt, depending greatly on the age of the female
Why do we try to get so many eggs for “standard” IVF?
IVF success rates are much higher with a “good” number of eggs due to the substantial drop-off that is seen in early embryo development.
The chart below shows the average number of eggs, mature eggs, fertilized embryos, “good” embryos on day 3, blastocyst embryos on day 5, etc. in three age groups of women at our clinic.
- If there are extra embryos available for freezing, we freeze on day 5 and day 6 (possible freezing shown by purple arrow going up).
As shown in the chart, in the average case there is progressive drop-off over time with in vitro fertilization. Human reproduction is not extremely efficient – if we were mice or cows we would be efficient reproducers. Alas, we are not so lucky – we are stuck being human…
So if we do mild IVF and we only get a few eggs instead of a larger number as in standard IVF, do we still get enough to end up with a good pregnancy success rate?
- The short answer is no. On the average, low egg numbers will translate over to low chances for success.
- With mini or micro-IVF:
- The IVF stimulation process is easier for the woman
- Medications are cheaper
- The cost for one cycle of IVF should be substantially less
- But the pregnancy success rate is much lower compared to conventional in vitro fertilization
- What good is cheap and easy if you don’t have a baby?
What is the best number of eggs to get?
- The answer depends on what the goal is
- > 10 eggs = The highest possible chance for success – and likely to have leftover embryos for freezing
- 5-9 eggs = Slight to moderate reduction in the fresh cycle success rate – and reduced chances for having leftover embryos for freezing
- 1-4 eggs = Substantially lower success rate, particularly in older women – almost never any leftover embryos for freezing
- The chart below shows our live birth rate per egg retrieval procedure by age group and number of eggs retrieved
- Read more about number of eggs and IVF success rates by age
Let’s review some of the claims made by some US IVF doctors that are pushing mini-IVF
- Claimed by some fertility doctors: “Mini IVF is a cost effective treatment option for young women attempting to conceive”.
- This depends on how you measure “cost-effectiveness”. If the total cost for a successful cycle (baby) is the measure, then mini-IVF will not measure up to the cost-effectiveness of conventional in vitro fertilization at a clinic with high IVF success rates.
- For example, if it costs half as much for the IVF cycle (including all medications) but the success rate is 1/4 of standard IVF at a good program – then it is not “cost-effective”. In this example the average cost per live birth would be twice as much for mini-in vitro fertilization as for standard IVF.
- Claimed by some fertility doctors: Mini-IVF is a dramatically lower cost option that simplifies IVF for patients and maintains the same success rates”.
- It’s not polite to call another doctor a liar, but this is simply not true. Unfortunately, not all fertility doctors tell the truth.
- Mini or micro IVF has a much lower chance of success for the large majority of couples.
- Claimed by some fertility doctors: “For older patients, the success rate with micro-IVF is even higher than with conventional IVF”.
- This is generally not true. As shown in the chart above, our in vitro fertilization program had a 7% live birth rate per egg retrieval procedure for women 41-42 if they had 1 or 2 eggs vs. 35% if they had over 10 eggs (yellow columns on chart). Mini-IVF tends to produce low egg numbers.
- However, it is possible that the success rate would be similar for standard and mini-IVF for the subset of women that respond very poorly to aggressive stimulation with standard medication protocols.
- Either method would be likely to give them a low number of eggs to work with and a low chance for success.
Mild IVF is a reasonable option for some patients
- However, in the US it is a situation of “buyer beware” as it is being aggressively sold by some clinics using sales pitches full of hype and little truth.
Richard Sherbahn, MD is a fertility doctor practicing in the Chicago, Illinois area.
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