The following post was placed in the ASK the DOC section by Catherine99. I am reposting it here because I think that everyone should read it and my response below. The post was as follows: link to interview:

http://www.imagineyh.com/html/features/infertility/article/article_nov00_1.php3

Catherine99: Hey Maureen, i'm just as confused as you are... i was quite surprised to read Dr. Potter even mentioning Gradient Selection in the interview...but apparently it gets better PG rates than MS/IUI. I have asked Dr. Potter many times to clarify this for the past several weeks and still no reply from him... it IS confusing and if what he says is true about gradient selection having a 70-75% success rate then it should be promoted instead of Microsort for people who want boys since the stats are the same for both methods. Quote from interview: "The problem with Microsort, in my experience, has been that the specimens are so depleted that only several hundred thousand sperm are being inseminated at a time, says Dr. Daniel A. Potter, of the Huntington Reproductive Center. "So the pregnancy rates are very low." The pregnancy rate is 16 percent, below the natural conception rate. Dr. Potter employs the other method: gradient selection. "It is based on a simple physics equation: force equals mass times acceleration." ....gradient selection is often a more attractive option to prospective parents because it is cheaper, performed in various clinics around the country, and the rate of successful insemination is higher than Microsoft's. The reason: the gradient method is easier on the sperm. Dr. Potter explains, "We will lose about half of the sperm when we do the procedure, but we will concentrate the sperm we do have and deposit them high up in the uterine cavity. So the pregnancy rate turns out to be as high as if the couple were having intercourse that month, that is to say about 20% per attempt." According to Dr. Potter, gradient selection is highly effective in selecting the sex of a child. "The success rate is about 70 to 75 percent. It is a little higher in girls."

Catherine99: "Yes, curious why Dr.Potter wasn't a "fan" of Microsort and then did a 180 degree turnaround when it was offered at HRC a couple yrs later... no mention of Gradient Selection as a service at HRC since... i still am of the opinion if GS has the same "success" as MS for males, then people should be counselled on the $500 option instead of the $3400 one."

This is my response:

As you can see from the header of the interview posted by Catherine99, it was published in November 2000, which means that the interview must have been conducted sometime prior to that. I will let the readers decide whether or not the above referenced posts were innocently posted out of context or a willful attempt to impugn my integrity. The simple truth is that, as I acquired more data and experience, I realized that spinning did not work. I was also skeptical of MicroSort at that time. I only accepted MicroSort fully after they had a sizable experience and upon seeing unpublished data submitted to the FDA. This was all before I was associated with MicroSort in any way whatsoever. Also, MicroSort was never 'offered to HRC'. I went back and got it after I knew that it worked. If you would like to see how a medical opinion evolves, read on. When I joined HRC in August 1998, they had been doing gradient separation for gender selection for over 10 years. A small study published by our medical director at the time was one basis for its use along with my initial experience:

Batzofin J Urol Clin North Am. 1987 Aug;14(3):609-18.

During my first 2 or so years at HRC, I offered gradient separation. I kept track of my results. At first, it seemed to go fairly well with the gender ratios of as mentioned in the interview. As I accumulated more data, the gender ratio regressed toward 50:50. The straw that broke the camel’s back was a local attorney who had 2 boys and got her 3rd and 4th boys with non-identical twins using gradient selection IUI.[1] At that time, I stopped recommending spinning but would still do it if patients insisted. We decided to use the new tool of PGD to see if spinning changed the gender ratio in embryos. The paper was completed and submitted in 2002 and presented in early 2003.

Boostanfar R, Ivakhnenko V, Potter D, Feinman M, Behr B. Preimplantation genetic diagnosis after density gradient separation of the X and Y-bearing human spermatozoa. Presented at the 51st Annual meeting of the Pacific Coast Reproductive Society, April 24-27, 2003, Rancho Mirage, California.

It showed that the gender ratio in embryos created with spinning was no different than those not prepared for gender. I also had begun to look more closely into MicroSort. MicroSort was very slow to publish its data and many of us in the reproductive community were skeptical. As of November 2000, the public was aware of:

Efficiency of MicroSort flow cytometry for producing sperm populations enriched in X- or Y-chromosome haplotypes: a blind trial assessed by double and triple colour fluorescent in-situ hybridization. Hum Reprod. 1998 Feb;13(2):308-12.

Births of normal daughters after MicroSort sperm separation and intrauterine insemination, in-vitro fertilization, or intracytoplasmic sperm injection. Hum Reprod. 1998 Sep;13(9):2367-70.

Human live birth and sperm-sex ratios compared. Hum Reprod. 1999 Nov;14(11):2917-20.

Preliminary study of the incidence of disomy in sperm fractions after MicroSort flow cytometry. Hum Reprod. 1999 Dec;14(12):2987-90.

In 2000, I visited their facility and was able to look at the unpublished data submitted to the FDA. I became a believer in the MicroSort process. As I saw the results of the patients that I sent back to Fairfax, I my belief was confirmed. By 2001-2002, I was working on getting a facility out to the west coast. My opinion has always been public and has always been consistent with my interpretation of the best available data and the best interest of my patients.

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1[Caution: happy ending alert] BTW, she came back for a 5th with MS/PGD and got her girl!