Question #6: How does NC-IVF compare with stimulated IVF?
In answering this question I compared NC-IVF to the Society for Assisted Reproductive Technologies (SART) data for all IVF clinics reporting to SART for 2007. The implantation rate (pregnancy per ET) was outstanding for NC-IVF (over 35%). So if a patient made it to transfer the odds of pregnancy were excellent. Does that mean that NC-IVF produced better embryos or a better lining or both? It is hard to say, but the concept that Mother Nature may provide a better outcome is certainly intriguing.
Question #6: What about OHSS and multiples?
Well the incidence of OHSS with NC IVF is 0%. One can't have OHSS without fertility drugs so with Natural Cycle IVF there is essentially no risk of OHSS. Multiples are also very rare. The only twin pregnancy we have had so far was a case of identical twins. Interestingly that patient had a child from stimulated IVF with us but was a very low responder with only 3 eggs. She elected to give NC IVF a try and with her first cycle she had a beautiful blastocyst and ended up with identical twins. Go figure..... 3 eggs for thousands of dollars and one baby vs. one egg for a fraction of the cost and twins. Never a dull moment in reproductive medicine.
The reason for the lack of twins is simply the fact that there is almost always only a single follicle, a single egg retrieved and a single embryo available for transfer. Nationally, we still transfer too many embryos as seen below.
This phenomenon then directly influences the multiple pregnancy rate which is over 30% for patients younger than 30 years old and 24% for those patients between 35 and 39 years old. Elective single embryo transfer is attractive to consider but in reality not that many patients will elect to transfer only one embryo. Natural Cycle IVF solves that dilemma for the patient as there is almost always just a single embryo available.
The risk of twins is mainly that of prematurity. Although patients are often thrilled with twins, we are happier with singletons. The pregnancies are less complicated and the outcomes are better.
As far as we are concerned, Natural Cycle IVF is here to stay. Our extensive experience has demonstrated that acceptable pregnancy rates can be achieved, especially if NC IVF is integrated into a fertility practice as a viable treatment option and not relegated to use only in extremely poor prognosis patients. In looking at our data from 2007-2009 we inform our patients that if they are younger than 40 years old then they can anticipate the following odds: I cannot emphasize enough how much patients appreciate having this option as a bridge. Many who have failed clomid/IUI or clomid/FSH/IUI are much happier trying NC IVF than full stimulated cycle IVF. Some patients who have known for years that they need IVF have been ecstatic that they have a new option. Some low responder patients with diminished ovarian reserve have pursued NC IVF as opposed to egg donor IVF or adoption. Although success rates in these patients are certainly lower than with donor egg IVF or adoption (we anticipate that 10-12% of these poor prognosis patients may still achieve a pregnancy with Natural Cycle IVF), many patients are not open to alternative pathways to parenting...at least not until they feel like they have exhausted all options.