January 2006 - Posts
This is going to come as a shock to followers of the Shettles gender selection method: research using the most reliable and advanced techniques for analyzing human sperm has revealed that there is no difference in the size and shape of X and Y sperm -- a finding in direct conflict with Shettles' main principle.
The study appears in the latest issue of Fertility and Sterility, the respected journal of the American Society for Reproductive Medicine (ASRM). The conclusion agrees with some previous studies showing that X and Y sperm cells have the same morphology (size, shape, and structure).
So what does this mean for the Shettles method? In his book, Dr. Shettles claims the size difference between the two types of sperm -- X and Y, with the X's responsible for the conception of a girl and the Y's causing the conception of a boy -- is the key to swaying the odds in favor of conceiving the gender of your choice. Because the Y chromosome is smaller than the X chromosome, Shettles theorized, the Y-bearing sperm should be smaller and faster. The greater mass of the X sperm, on the other hand, should make it slower but hardier and better able to overcome obstacles to fertilization.
There's no dispute that the X chromosome is bigger than the Y chromosome, as this photo clearly shows. But the sex chromosome is only one of the 23 chromosomes carried by a sperm -- in total, an X sperm carries only 2.9% more genetic material than a Y sperm. As you can see, the difference isn't that great.
Total DNA in X Sperm
Total DNA in Y Sperm (2.9% less)
Data from the study shows that, not only are X and Y sperm indistinguishable from one another, even abnormal sperm cells with the wrong number of chromosomes -- too many or too few chromosomes -- cannot be identified by having a different shape or size.
Shettles describes how he observed two distinct populations of sperm: smaller, pointier sperm that he assumed were Y sperm, and bulkier, rounder sperm that he assumed were X sperm. However, Shettles never proved that the different-appearing sperm cells he saw actually corresponded to X and Y sperm. We now know for a fact that it is impossible to identify a living X from a Y sperm just by looking at it with a microscope, no matter how powerful the microscope is. (If it were, we'd have a reliable method of gender selection without resorting to PGD.)
The truth is that at the time Dr. Shettles conducted his interesting sperm experiments -- more than 4 decades ago -- there didn't exist an accurate method of detecting X and Y sperm in a semen sample.
Two sperm at different stages of maturity
What has been shown by recent research is that sperm shape indicates maturity, not whether the sperm is carrying an X or Y chromosome. Sperm cells which have undergone "capacitation", which occurs after ejaculation and enables a sperm cell to fertilize an egg, are pointy. Sperm cells which have not undergone this process are round and enlarged, and cannot fertilize an egg.
It seems clear that Dr. Shettles sincerely wanted to find a method that would help parents choose the sex of their baby. But was his theory founded on wishful thinking? Did his dream of finding a useful difference between X and Y sperm lead him to make a false assumption when he saw differently-shaped sperm cells under the microscope?
No, you're not accidently reading "The Onion" by mistake, this really happened.
Baby Gender Mentor has been selected as one of the top 10 best products of 2005 in Datamonitor's "Build a Better Mousetrap" report, according to the Glasgow Daily Record.
Datamonitor is actually a well known market analyst, not, as you are probably thinking at this point, a bunch of crackheads. Datamonitor describes itself as a "premium business information company specialising in industry analysis" providing "unbiased expert analysis".
"Next time maybe do a little research."
Apparently "expert analysis" in this case translates to "watching Katie Couric on the Today Show and counting how many other media outlets copy the story" because this company sapiently selected a Top 10 product which has resulted in an avalanche of complaints from pregnant mothers, been the subject of critical articles by NPR, Boston Globe, and Newsweek, and its online retailer is under investigation by the state attorney general for consumer fraud.
A new at-home fertility test for men and women called Fertell goes on sale today in the UK, and is scheduled to be available later this year in the US. Some fertility experts have praised the product, saying that it will help couples identify fertility problems before spending a year trying "fruitlessly" to get pregnant, as many doctors advise.
I think this is a nifty product, but I'm not sure it's worth the hefty price of $140 (£80 in the UK), because you could obtain the same tests at a medical lab for about the same price.
- Female fertility test: A urine test measures the level of FSH hormone. By comparison, the cost for a more exact test in a lab is about $100.
- Male fertility test: A semen test determines if sperm are able to swim through a barrier that simulates the cervix. By comparison, the cost for a complete semen analysis in a lab is about $50.
Fertell female fertility test -- Testing your FSH level
About FSH testing: FSH (follicle stimulating hormone) is a hormone in your urine, and it communicates the message each month to your ovaries that it is time to ovulate, or release an egg.
If this level is elevated, or too high, this indicates a fertility problem, meaning that you may have too few eggs, or poor quality eggs. This happens as women grow older, so an FSH test is of interest to you if you are 35 or older and trying to conceive. Any woman who is preparing to get pregnant by IVF will have an FSH test, and if your FSH level is too high, you may be rejected for treatment because you are considered to have a poor chance of getting pregnant.
How to take the test: It's a simple POAS (pee-on-a-stick) test, taken on cycle day 3.
Test results: The test shows a reference line, which represents an FSH level of 10. If your test line is lighter, that means your FSH level is lower than 10, and that's good. If your line is darker, your FSH level is higher than 10, and it might mean you're going to have a hard time getting pregnant.
Is it accurate? Fertell says this test is 95% accurate when used by consumers.
What you should know: A high FSH level indicates a problem, but on the other hand a low FSH level doesn't necessarily mean "everything's okay". You may still have other fertility problems that prevent pregnancy. Also, I would be very wary of interpreting a good FSH level as meaning, "hey, I'm in great shape, it's okay to wait 5 more years to try to get pregnant". When it comes to fertility, time is your enemy; don't be fooled into forgetting that.
Alternatives to the Fertell female fertility test
- A Day 3 FSH test performed in a lab, $100. This test will tell you your exact FSH level (not just whether it is over/under 10). If you are approaching 35, talk to your OB about an FSH test; this could be an extremely important test for your future fertility.
- At-home FSH test strips cost just a few dollars, but they are much less sensitive than the Fertell test. These will only tell you if your FSH level is very elevated (25 or higher). Your FSH level can still be way too high to be accepted for IVF, for example, and not be detected by these strips. However, if you are concerned about your fertility because you are 35 or older, it may be worthwhile to spend $2 to make sure that your FSH level is at least below 25 before spending $100 or more on another test.
In summary, the Fertell female fertility test is less precise than the same test performed in a lab, but it's far more useful than other at-home FSH tests, because it can tell you whether you have a close to normal FSH level, or a borderline level.
Fertell male fertility test -- testing sperm
The Fertell male fertility test is an amazing gadget that determines whether a man's sperm are likely to be able to swim to the egg.
How to take the test:
- A semen sample is collected right in the test cup.
- At the press of a button, the test device measures a specific amount of semen, then layers a column of fluid over the semen. This fluid mimics cervical mucus (CM), the fluid found in the vagina through which sperm must swim to reach the egg.
- The test unit also automatically heats the fluid to normal body temperature. Wow!
- Motile sperm (good swimmers) travel up through the fluid. If enough sperm complete the journey, a line on the test strip gives a positive result.
Alternatives to the Fertell male fertility test
- A semen analysis performed in a lab, about $50. And NO, you do not have to produce the semen sample by yourself in the clinic, you can do it at home if you can get it to the lab within 30 minutes or so. There are even special condoms used to collect semen for a semen analysis. A semen analysis will give you more information than a simple Yes/No result like the Fertell test; you will get actual numbers for sperm count, motility, morphology, etc.
- The FertilMarq Male Fertility test, about $40. Despite the fact that the media has been calling Fertell the "world's first over-the-counter home fertility test for men," the FertilMarq test has been available for about 2 years. FertilMarq simply measures whether your semen has a high enough sperm count. The kit includes two tests and condoms for semen collection. This test only measures how many sperm are present, unlike the Fertell test which also tells you whether they can swim.
In summary, the Fertell male fertility test is a fascinating contraption, and it provides one interesting and useful measurement of whether your sperm are likely to get the job done. However, semen quality is quite variable, and if you have poor semen quality, there's a good chance you can improve it by changing your lifestyle; improving your diet, taking vitamins, reducing stress, and quitting smoking and drinking, can all improve your sperm quality. But unfortunately you can't buy the male test alone, so if you'd like to test again to see if you've improved using the Fertell test, you'll be out the full $140 again.
What Maureen really wants to know...
What I really want to know is whether that semen test gizmo is reusable, because it would be interesting to fill it with real cervical mucus. Many women have trouble conceiving because their cervical mucus isn't hospitable enough to the sperm, and it would really be useful for couples to see if YOUR sperm can swim through MY cervical mucus, perhaps at different points in the cycle.
And another thing I'd like to know... was it really a great idea to use this picture on the Fertell web site, as an illustration of a product that uses urine and semen? Yuck.
How to buy Fertell
Currently Fertell is available only from Boots the Chemist Web site and stores in the UK. It is planned to be sold in the US in Q3 of 2006.
A new medical study confirms, yet again, that fetal heart rate can't tell a pregnant woman if her baby is a boy or a girl.
As the old wives' tale has it, if your unborn baby's heart rate is higher, above 140 beats per minute, that means you're carrying a girl. A lower heart rate below 140 bpm means you're having a boy.
It's hard to resist such an easy test, because for nearly every woman in the early stages of pregnancy, the baby's heart rate is just about the only thing we can find out about it. So it's easy to try to over-analyze this little bit of information we can get.
But don't get your hopes up, or have your hopes dashed, based on your baby's heart rate, because it has absolutely nothing to do with what your baby has between its legs. This was proven beyond question 20 years ago, by a senior sonographer who analyzed thousands of births to establish that fetal heart rate did not correlate with the baby's sex. (See link to study below.)
Quite convincing data, but still I decided to conduct my own experiment to see if fetal heart rate could indicate a baby's gender. To do my experiment, I first became pregnant with boy/girl twins. Then, I underwent a LOT of fetal heart monitoring, including one week of almost constant monitoring while hospitalized for preterm labor, as well as twice-weekly non-stress tests in which both babies heart rates were tracked for 30 minutes. (You can see I am quite dedicated to the interests of science.)
The result? Sometimes the boy's heart rate was higher, sometimes the girl's heart rate was higher. No pattern, except that when one of the babies seemed to be more active, kicking and moving around alot, that baby's heart rate would tend to be higher. It makes sense, that a baby's heart rate might vary a good bit depending on whether it's active or at rest at the time the heart rate is checked.
As if my own research weren't convincing enough, a new study, published in Fetal Diagnosis and Therapy, tells us that analysis of over 500 births proves again that fetal heart rate cannot predict whether a baby is a boy or a girl.
Contrary to beliefs commonly held by many pregnant women and their families, there are no significant differences between male and female fetal heart rate during the first trimester.
Medical study, link below
So the next time you see a post in a pregnancy forum from a mother "proving" this theory is right because her two girls had high heart rates and her three friends had boys with low heart rates, you can set the record straight on this old wives' tale: it's false.