Also known as gender selection or gender swaying, there is a mixture of misinformation and (very little) science out there. Most advice is harmless, such as timing intercourse to certain points during ovulation. However, some methods can be harmful. For instance, sex selection diets can be dangerous, and some false gender swaying methods, such as douching, can cause vaginal infection and actually decrease the odds of you getting pregnant at all. On the other hand, there are assisted reproductive technologies that can help you have a girl or a boy. However, these are expensive, come with medical risks, and are still not 100% guaranteed. Plus, not all fertility clinics offer sex selection technology without medical need. There are many reasons why a parent may hope to choose the sex of their future child. These include medical issues, cultural biases, and personal preferences. Understandably, there are many ethical dilemmas related to preconception sex selection to consider. Learn more about popular “natural” methods on gender swaying and research-proven ways to conceive a girl or boy. Also, take a look at whether or not to pursue methods to influence the sex of your baby.
Why Parents May Hope for a Boy or a Girl
There are medical and non-medical reasons a parent may want to have a child of a specific sex. On the medical side, sex-linked genetic diseases may be a concern. For example, hemophilia and Duchenne muscular dystrophy almost always occur in boys. If a family has a history of these diseases, they may wish to conceive a girl to reduce the chances of passing on the condition to their child. However, most people hoping specifically for a boy or girl want to do so for non-medical reasons. The most common reasons are a preference for one gender over another (historically, boys) or family balancing. This is when a family already has a child (or many children) of one sex and hopes the next child will be of the opposite sex. Or, if a couple decides to have two children, and they already have one child, they may be more determined that their second child be the other sex. In some families that already have all boys or girls, couples may be hoping that the next one will “finally” be a baby of the opposite sex. Family balancing is usually an immediate family consideration, but it can also be an extended family issue. For example, if a grandparent has only granddaughters, one of their children may hope to give the grandparent a grandson (or vice versa). Other reasons a person may prefer to have either a boy or girl include:
Experiencing the death of a child: If a parent loses a child, they may hope to have another child of the same gender. Alternatively, they may want to have a child of the opposite sex, to try to mitigate traumatic memories associated with their loss. Having cultural or religious reasons: Some cultures and beliefs favor one sex over the other. For example, in many cultures, there is a strong historical (and in some cases, current) preference for boys. On the other hand, some religions forbid any form of preconception sex selection.Preferring to raise a child of a specific sex: If a couple plans to have only one child, they may strongly prefer that child be a boy (or a girl). Or, a planned single parent may feel more comfortable raising child of the same sex—or hope for the opposite.
What Determines the Sex of Your Child
The X and Y-chromosomes (also called sex chromosomes) determine a person’s biological sex. The egg always carries one X chromosome, while the sperm either contributes an X or Y to the embryo. If a Y-sperm fertilizes the egg, you get XY—a boy. If an X-sperm fertilizes the egg, you get XX—a girl. (There are rare genetic diseases where an additional sex chromosome is present, like with Klinefelter syndrome, XXY) It’s assumed that half of the babies born are boys and half are girls, but that isn’t actually true. The current global male-to-female ratio is 105-107 boys for every 100 girls born. While this means that slightly more boys are born than girls, this doesn’t necessarily translate into heightened odds of having a baby boy. The dynamics of natural sex selection within a family are complicated and can be affected by the length between pregnancies, birth order, exposure to environmental toxins, maternal diet and health, and other factors (many of which are unknown).
IVF With PGD
This assisted reproductive technology was invented to help avoid particular genetic diseases, and that is still its primary use. However, IVF-PGD can also be used to conceive a child of a specific sex for non-medical reasons. IVF with PGD is medically invasive and very expensive, making it out of reach for the vast majority of families. Even those who need IVF due to infertility often can’t afford the treatment. With IVF, fertility drugs are used to stimulate the ovaries. The idea is to get the ovaries to mature many eggs, instead of the usual one or two that occur in a natural cycle. At about mid-cycle, while under anesthesia, an ultrasound-guided needle is placed through the vaginal wall to retrieve the eggs. A partner or sperm donor provides a sperm sample. Then, in the lab, the eggs and sperm are put together. Hopefully, some of the eggs will become fertilized. Fertilized eggs are embryos. For the PGD part of the procedure, a few cells are biopsied from the developing embryos. These are sent for genetic evaluation. This is how it is determined which embryos are XX (girls) and XY (boys). The parents can then decide which embryos are transferred back into the birthing parent’s uterus. For example, if the parents only want a girl, then only XX embryos would be considered. Before you consider IVF, it’s extremely important you understand all the risks to the pregnant person and baby. PGD comes with its own set of risks and costs. Note that even IVF with PGD is not 100% guaranteed. Errors and mistakes occur. Also, not every fertility clinic is willing to offer IVF with PGD for non-medical reasons. Some clinics will consider it for family balancing. There is no guarantee you will get any embryos of the sex you prefer. You could get all XX or all XY embryos. (Sperm sorting may improve your odds; see more on this below.) There’s no guarantee you’ll get a baby of the sex you want. Just like IVF isn’t a pregnancy guarantee, a transferred embryo doesn’t mean you take home a baby. You’ll need to consider what you’ll do with the extra embryos of the sex you didn’t want. (You could possibly donate them to an infertile couple, dispose of them, or offer them for research.) Making this decision can be emotionally and ethically challenging.
Sperm Sorting
There is another medical technique that is not as successful as IVF with PGD, but it has more scientific validity than any of the so-called “natural” methods. That’s sperm sorting, specifically with a technology known as flow cytometry. The technology is patented under the name MicroSort. MicroSort was under FDA consideration for several years, but the company conducting clinical trials in the United States withdrew its application. MicroSort is no longer available in the U.S., and the FDA never officially approved or disapproved the technology. Sperm sorting with MicroSort works something like this. The semen sample is provided and goes through a special washing process to remove seminal fluids and non-moving sperm. Then, the sperm cells are stained with a special dye that reacts with DNA content found in sperm cells. The sperm cells are placed in a flow cytometer, which is a technology that enables the identification of particles in a fluid as they pass by a laser. X-sperm cells contain more DNA content than Y-sperm cells, so the dyed X-sperm cells light up brighter when they pass by ultraviolet light. This is how the sperm cells are sorted and identified, one by one. The technology is not perfect. It’s currently impossible to get a “pure” x-sperm or y-sperm sort. The X- or Y-concentrated sample is then either transferred to the uterus via IUI, or they can be used along with IVF alone or IVF-PGD. The following are success rates from MicroSort clinical trials:
For those who wanted a girl, the female sperm samples contained 87% X-carrying sperm cells. When used for insemination or with IVF, when pregnancy and birth were achieved, 93% of the conceptions resulted in a girl.The male sperm sorted samples contained 74% Y-carrying sperm cells. When a successful pregnancy and birth were achieved, 85% resulted in a baby boy.
The percentages above refer to the success of getting the sex desired by the intended parent or parents. These are not the success rates for fertility treatments in general. The IUI cycles in this study resulted in a clinical pregnancy 15% of the time. The IVF cycles had a 32% clinical pregnancy rate, and the frozen embryo transfer cycles had a 33% clinic pregnancy rate. These were comparable to the success rates expected without sperm sorting technology. It’s unknown what risks there may be to exposing sperm cells to the dye, the ultraviolet light, or high pressure created in the flow cytometer. There may be an increased risk of chromosomal damage to the sperm cells, but currently, we don’t really know. As mentioned above, MicroSort is no longer available in the U.S. You’d need to travel abroad to use it. Medical tourism for fertility treatments has its own risks, costs, and benefits to consider.
Ericsson Albumin Method
The albumin filtration method of sperm sorting—better known as the Ericsson Albumin Method—is a controversial technique of preconception sex selection. Discovered and patented by Dr. Ronald Ericsson, this is currently the only form of sperm sorting technology available in the U.S. The effectiveness of this method is highly debated. There are studies (many of them involving Dr. Ericsson himself) that have reported that the method can tip the scales towards one sex or the other, but there are also studies that have not found any success using the albumin filtration method. Essentially, the Ericsson method involves placing specially washed sperm cells on top of a layered solution of albumin. Albumin is a kind of protein naturally found in semen. The albumin is layered with increasing thickness, with the thickest layer at the bottom. The idea is that the Y-sperm cells will swim down and reach the thickest layer faster. Why this occurs—whether due to speed of the Y-sperm cells or their lighter density compared to X-sperm cells—is unclear. For those who want a boy, the filtration method is followed by insemination (IUI). For those who want a girl, IUI is also used after the sperm cells have been filtered, but the fertility drug Clomid is added to the treatment protocol. It’s said that Clomid changes the cervical mucus, making it more favorable to X-sperm cells. However, there is only limited research to back this up. What are the chances of getting the sex you want? Reported success rates using the Ericsson method vary. A 2014 study found success rates of between 69% and 75%. Keep in mind, of course, that you already have around a 50% likelihood of getting your desired boy or girl without doing anything.
Shettles Method
The Shettles method of sex selection is widely popularized lore on how to conceive a boy or girl. Invented by Dr. Landrum Shettles, who was an early IVF pioneer, the method is based on his observations of sperm behavior in the 1950s lab. For example, much of the method assumes that Y-sperm swim faster than X-sperm. Dr. Shettles came to this conclusion by observing the size and behavior of sperm cells. He noticed that smaller sperm cells swam faster than larger ones, and decided the smaller sperm cells must be Y-carrying and the larger ones X-chromosome carrying. Many follow-up scientists made the same assumptions, based on Dr. Shettles’ work. However, computer-assisted sperm analysis (CASA)—which wasn’t invented until the mid-1980s—has found that this is not accurate. Y-sperm cells do not swim any faster on average than X-sperm cells. Here’s what the Shettles Method says and what the problems are with the theory.
Shettles’ Tip #1
If you want to have a boy, Shettles’ theory advises having sexual intercourse as close to ovulation as possible—ideally, within 12 hours before your expected ovulation. The method also calls for avoiding sex (or using contraception) until you reach this time. The theory is that the Y-sperm cells will arrive at the egg faster before the X-carrying sperm cells can. If you want to have a girl, on the other hand, the theory holds that you should have sex every day once your period ends, up until two to four days before you expect to ovulate. Then, avoid sex. The method also calls for avoiding sex (or using contraception) when you have the most fertile cervical mucus present. The theory being that the X-carrying sperm cells are slower swimmers but will survive longer than the Y-sperm cells, and only X-carrying sperm cells will still be there when the egg is ovulated. The problem with this advice: It is impossible to time sex to be exactly 12 hours before ovulation. Research has found that no method of at-home ovulation tracking is that accurate. Avoiding sex in the two days before you expect to ovulate means you are missing your most fertile days. Also, avoiding sex when you have egg-white quality cervical mucus also means you’re avoiding your most fertile time. Your overall odds of getting pregnant at all—with either a boy or girl—go down. Plus, most important, follow-up studies on sexual intercourse timing (and other “natural” methods) have found mixed and inconsistent results. Some found that having sex close to ovulation increased the odds of conceiving a girl, other studies found it increased the odds of conceiving a boy, and some found it made no difference at all.
Shettles’ Tip #2
If you want a boy, Shettles calls for having sex using the rear-entry position, which is commonly known as “doggy style.” The method holds that you should use sexual positions that get the semen as close to the cervix as possible to give the “faster” Y-sperm cells an advantage. If you want to have a girl, the method claims you should have sex in the missionary position along with a “shallow” entry, so the semen is deposited slightly away from the cervix, where the vaginal environment is slightly more acidic. The problem with this advice: Sexual position doesn’t impact how quickly particular sperm cells get to the egg. We now know that Y sperm cells do not swim faster than X-carrying sperm cells.
Shettles’ Tip #3
Shettles also calls for douching with vinegar to increase the acidity of the vagina if you want to conceive a girl to give X-sperm cells an advantage. Dr. Shettles believed X-sperm cells were tougher than Y-sperm cells. The problem with this advice: Douching can disturb the natural pH balance of your vagina. This can lead to irritation and infection, and remove the fertility-boosting cervical mucus that helps all sperm cells (the “boys” and the “girls”) survive. In the end, douching can decrease your overall odds of getting pregnant at all.
Shettles’ Tip #4
If you want to have a boy, Shettles’ method also says that the woman should have an orgasm, which the theory claims helps the Y-sperm cells to swim even faster. If you want to have a girl, the woman shouldn’t have an orgasm. Also, according to Dr. Shettles, not having an orgasm will make the pH balance of the vaginal environment less favorable to Y-carrying sperm cells. The problem with this advice: As mentioned above, we now know that Y-chromosome-carrying sperm cells do not swim faster on average than X-carry sperm cells. Also, there’s no evidence that having or not having an orgasm will affect the sex of the child you conceive. However, there is some evidence that having an orgasm will boost your likelihood of getting pregnant. So, don’t deny yourself an orgasm if you want one.
Whelan Method
The Whelan Method is based on the advice of Dr. Elizabeth Whelan, who was an epidemiologist (an epidemiologist is a scientist who studies disease). Her method is based on the 1970s research of Dr. Rodrigo Guerrero. Dr. Guerrero found that the odds of conceiving a boy were slightly higher if sexual intercourse occurred many days before ovulation and that the odds of having a girl were slightly higher if intercourse occurred just before or after ovulation. This is the exact opposite advice of Dr. Shettles. Presumably, they can’t both be right. Of note, while there are many studies using a variety of methods that have shown a link between intercourse timing and predicting the sex of the baby, there are others that refute the idea. Dr. Whelan claims that for those trying to have a boy, 68% got their boy, and for those that wanted a girl, they were successful 58% of the time. There’s been no outside confirmation of these statistics.
O + 12 Method
The O + 12 method—which stands for ovulation plus 12 hours—was said to be invented by a woman who wanted to have a girl but kept having boys with the Shettles method. The idea here is that if you want to have a girl, you time sexual intercourse for 12 hours past ovulation. Also, you only have sex one time. Besides there being no studies on this method, there are two big problems. One, it’s impossible to time sex to occur exactly 12 hours after ovulation because you can’t detect the exact hour (or even day) that you ovulated. The only way to do so would be with frequent ultrasound examinations. Even then, the moment of ovulation would likely be missed. If you’re thinking that your basal body temperature chart tells you the day you ovulated, research has found this to be untrue. While BBT charting can give you an idea of when you ovulated, the temperature rise does not accurately detect the exact day the egg was released from the follicle. It certainly can’t tell you the exact hour. The egg only lives 12 to 24 hours after it is released. You may completely miss your chance of getting pregnant if you attempt having sex only once, and only after you ovulated.
Timing of Intercourse
As noted above, there are a variety of conflicting theories and studies on the efficacy of timing intercourse to improve your odds of having a boy or a girl. This is a very difficult subject to study because you can’t really completely control the experiment. You can’t lock couples up in a lab for months while they try to get pregnant. Plus, most of the time, sex occurs on more than one day in a cycle. There have been many attempts to find the “magical” days to have a boy or girl, all with varying results:
Another researcher proposed that you’re more likely to have a boy if sex occurs days before ovulation.Another scientist suggested the opposite, claiming sex that occurs close to ovulation increases the odds of a boy, while a girl is more likely if sex occurs days before.As you already read above—just considering Shettles, Whelan, and O + 12—you can see many proposed methods contradict each other.One researcher postulated that if conception occurs on the day of ovulation, you’re more likely to have a boy. If it occurs two days earlier, you’re more likely to have a girl.
It would be nice (and easy!) if timing sex could sway the odds—but the current science says it’s unlikely.
Foods, Supplements, and Diets
There are a variety of theories about whether or not the maternal diet influences the sex of the baby they will have. Almost all gender-swaying diets fall within three basic categories:
Calorie and fat intakeFoods that apparently impact your body’s pHLowering or increasing intake of certain minerals
Most of these theories are anecdotal in nature and have little to no evidence to support them—and the studies that are available tend to be small, old, or limited in other ways.
Calorie-Fat Theory Diets
According to the calorie-fat theory diets, birthing parents who consume diets higher in calories are slightly more likely to have a boy. When diets are lower in calories, a girl is more likely. This theory was based on studies on the sex ratio changing during war and famine. While some specific time periods showed a shift in the sex ratio, other studies have not found this. It’s unlikely that the fat or calorie content of your diet will change your odds of having a boy or girl.
pH Diet Theories
According to the pH diet theories, you can shift the pH of your body toward being more acidic or more alkaline based on what you eat. More acidic is said to favor having a girl; more alkaline is supposed to increase your odds of having a boy. This is based on in vitro studies of how sperm cells react to environmental exposure. It’s true that in the lab environment, X-sperm can withstand more acidic conditions than Y-sperm. However, two problems arise:
It’s almost challenging to predict how sperm cells will react in a natural environment based on what happens in a petri dish.Secondly, your body works hard to maintain homeostasis or the conditions that are ideal for your well-being and health. That includes maintaining particular pH levels. Your pH levels change based on your hormones (that vary over your menstrual cycle), time of day, stress levels, and so many other factors. You can’t really control this on your own, especially to the degree of accuracy you’d need if it were possible to conceive a specific sex based on pH levels.
Mineral Gender Swaying Diets
According to the mineral gender swaying diets, a diet that is low in sodium and potassium, and high in calcium and magnesium, is said to increase the odds of having a girl. There was one small study on using this diet in combination with timed sexual intercourse. They completed blood testing to confirm the diet effectively shifted mineral levels. All couples were attempting to have a girl. During the diet, the women were to eat no prepared foods with salt, consume generous servings of dairy products (at least 500 grams per day), avoid potatoes (which are high in potassium), and take calcium (500 to 700 mg), magnesium (400 to 600 mg), and vitamin D supplements. Supplement dosages were varied based on blood work results. For the timing of sex, couples were told to avoid sexual intercourse in the two days before their expected ovulation date and for several days after ovulation was detected. This follows the sex-timing theory of Shettles to have a girl. The study had a very high drop-out rate, starting with 150 couples, and ending with only 32 women who met both the diet and timing of sex criteria. Of those, 81% gave birth to baby girls. The study also found that for those who didn’t get the timing right, but still kept to the diet protocol, their odds for a girl were higher (but not as high). Also, when it comes to taking supplements, or restricting particular mineral intakes (including salt and potassium), keep in mind this may be risky for your overall health. Before starting any diet or taking any supplements, talk to your doctor first.
Boxers vs. Briefs
Lab studies have found that X-carrying sperm cells can withstand slightly warmer temperatures than Y-carrying sperm. Based on this fact, for those that want to have a girl, men are encouraged to wear briefs. Briefs hold the testicles closer to the body, raising scrotum temperatures. Is there any proof that this makes a difference? No. In fact, one study showed that underwear choice did not significantly impact sperm quality or time-to-pregnancy intervals. Also, keep in mind that when you intentionally attempt to increase scrotum temperatures, you take a risk of lowering the overall sperm count—not just the Y-carrying sperm cells.
Changing Vaginal pH
The theory behind douching for preconception sex selection is based on the laboratory evidence that X-carrying sperm cells are hardier than Y-carrying sperm cells. Research (in Petri dishes) has found that X-sperm can tolerate more acidic environments and that Y-sperm does better in more alkaline environments. If you want a girl, the gender swaying advice sites claim you should douche with a vinegar solution, and if you want a boy, use a baking soda-based solution. Or also frequently stated, try coating your finger with baking soda and placing your finger into your vagina. (Also known as “baking soda finger.”) There are many reasons not to try it:
You may get an infection or experience vaginal irritation. Both of these can also decrease your odds of getting pregnant. You’ll wash away your cervical mucus, which you need to get pregnant. Your vaginal environment—by itself—creates the ideal conditions to keep sperm alive when you are more fertile. Douching can mess with the ideal pH values and end up killing all the sperm cells—not just the Y or X sperm cells you’re hoping to target.
At-Home Sex Selection Kits
There are products and “sex selection kits” you can purchase. They usually come with information or directions to follow, plus a variety of “tools” or supplements. They might include a douching device (usually with a recipe to follow to make at home), diet suggestions and menus, ovulation-tracking products like thermometers or ovulation test strips, and so on. You might get pH strips intended to test the acidity or alkalinity of your vagina, cervical fluids, or your partner’s semen. They may also throw in a pregnancy test or two. Some include online “support” groups or forums, often just a private Facebook group with other parents hoping to conceive a girl or a boy. Don’t waste your money. First of all, they won’t tell you anything that you didn’t read here, find for free elsewhere online, or in a book from the library. Second of all, it’s all based on very sketchy “science.” There’s no evidence that testing the pH of your cervical mucus is going to help you have a boy or a girl. The timing-sex-for-a-girl (or boy) theory is highly debatable. And there are no “magic” foods or menus that will ensure you have a boy or a girl. Third, when it comes to supplements, you’re better off purchasing supplements yourself. Also, keep in mind that the FDA does not regulate supplements—so you don’t even know if your “baby boy” mix contains what they say it contains, assuming they will even tell you what it contains before you purchase it. You can also purchase cheap ovulation tests, pregnancy tests, and pH testing strips yourself. These sites can be convincing. They may have glowing testimonials. But how do you know those people are real? And what about all of those who were not happy? Especially when the reviews are published by the company themselves, you have no way of knowing what stories you’re not reading. They may also offer a money-back guarantee, but does their guarantee include you getting your money back if you don’t get the boy or girl you’re hoping for? They can’t promise you this, so don’t expect more than can realistically be delivered.
But My Friend Did XYZ and Had a Boy/Girl
There are lots of posted success stories out there. You may find them in gender swaying forums and Facebook groups, or hear them from friends who swear by a particular method they tried. You might also read testimonials or reviews on sex selection product websites. Those that don’t have success are less likely to return to tell their tale. They may be accused of not following the directions closely enough. They don’t get the honor of sharing a success story. There’s no benefit to report they failed at their goal.
Ethical Concerns
While some doctors argue that the right to choose whether you have a boy or girl (within reason) falls into the broad category of reproductive rights, not everyone agrees. Many parents secretly or openly wish for a girl or boy, but there seems to be a line drawn when it comes to taking steps to make that wish come true. Here are some of the arguments against preconception sex selection:
Contradicts the concept of unconditional parental love: Just about every mother and father who really wanted a baby of one sex, but had one of the other, will tell you they love that child just as much. However, some question whether having such a strong preference before conception may interfere with unconditional love.Creates a risk of the child not meeting the parent’s gender expectations: A parent who wishes to have a girl (or a boy) may have specific ideas of what it means to be a girl (or boy). What if the child doesn’t meet those expectations? This may have psychological consequences and cause problems in the parent-child relationship.Creates a slippery slope toward “designer babies”: Some ethicists are concerned that if we start allowing people to choose the sex of their child, it will lead to parents trying to choose other aspects of a child’s genetics as the technology develops.Generates societal consequences, if one sex is favored over the other: In cultures where one sex is favored strongly over another, the ability to choose the sex of a child may lead to an imbalance of the societal sex ratio. This is already a problem in China, where boys are favored over girls. The latest sex ratio there was measured to be 113.5 boys to every 100 girls. Gender equality issues in education and other areas also suffer greatly in China.Produces religious objections to preconception sex selection: Some religions (or other belief systems) forbid taking any steps to attempt choosing or controlling the sex of their future child. Even in religions where one sex (usually male) is favored over the other, interfering with “God’s plan” may be frowned upon.
A Word From Verywell
Many people secretly wish for a child of a specific sex. Maybe they’ve always dreamed of raising a little girl or a little boy. Maybe they want to experience raising a child of each sex. These are common desires and nothing to be ashamed of. Despite these hopes, when the baby is born, just about every parent will say they fell in love. Once the child was here, the sex didn’t matter anymore. However, there are a few medical technologies that can help you have a child of a specific sex. That said, they can be very expensive (like IVF-PGD) or are not available in the U.S. (like Microsort). There are also a variety of “natural” sex selection methods, the vast majority of which have no scientific validity or stand on very shaky ground. While most methods are harmless, not all of them are risk-free. If you plan to pursue any of these options, talk to your doctor for guidance.
