How to have a girl or boy: Does sex selection work?

Does sex selection work?

Yes, there are sex selection methods that work, but the success rates depend on the method you use. At one end is reliable, clinically proven high-tech fertility treatment (IVF with preimplantation genetic testing). At the other is folk wisdom (such as making love standing up and eating more meat if you want a boy, and eating lots of chocolate and having sex in the missionary position if you want a girl). In between are low-tech sex selection techniques, such as the Shettles and Whelan methods (see below).

Keep in mind that Mother Nature has already tipped the odds a bit in favor of boys: In the United States, there are approximately 1,047 boys born for every 1,000 girls.

Note: The terms gender and sex are often used interchangeably when talking about this topic. But sex and gender aren't the same thing. A child's sex is what's usually assigned to them at birth, based on biology – the chromosomes and genitals they were born with. A child's gender relates to cultural standards and expected characteristics of men and women. And gender identity is based on a person's concept of themselves – how they feel and how they wish to express those feelings. A person's gender may not match their assigned sex.

Why do parents choose sex selection?

Sex selection is an option for couples who want to:

• Avoid passing a sex-linked genetic disease to their baby. For example, some females are carriers for over 350 X-linked diseases, even if they aren't directly affected by the disease. Hemophilia and Duchenne muscular dystrophy are examples of diseases that occur with a recessive gene on the X (female) chromosome.
• Reduce the risk of their baby having a disease more common in certain sexes. For example, a family who has a child with autism spectrum disorder (ASD) might try for a girl because ASD has a higher male incidence, and their chances of having another affected boy is 26 percent.
• Choose the sex of their baby because of a personal preference. Sex selection might appeal to parents who have a child or children of one sex and want to have a child of the other sex, for example. (This is sometimes called "family balancing.")

What are the different types of sex selection techniques?

Beginning with the most accurate technique, here are methods of choosing your baby's sex:

Fertility treatment: In vitro fertilization (IVF) and preimplantation genetic testing (PGT)

What it is

Infertility treatment is one way to try to choose your baby's sex. This safe and highly effective technique uses in vitro fertilization (IVF) and preimplantation genetic testing (PGT) in tandem.

Here are the steps:

• Fertility drugs. IVF starts with a round of fertility drugs to stimulate your ovaries to produce multiple eggs for fertilization, instead of the single egg typically released each month.
• Egg retrieval. When your eggs are ready to be retrieved, a doctor gives you an anesthetic and inserts an ultrasound probe through your vagina to check your ovaries and follicles (the fluid-filled sacs where eggs mature). On top of the ultrasound probe is a thin needle that goes through the vaginal wall to remove the eggs from the follicles in the ovaries.
• Fertilization. After retrieval, your eggs are fertilized with sperm in a petri dish. (In vitro means occurring outside the organism. In this case, it means fertilization is taking place outside your body.)
• Examination/testing. Five days after fertilization, the resulting embryos are examined and tested. Three to five cells are removed from an embryo and tested thoroughly for genetic or chromosomal abnormalities and the sex chromosomes X and Y. This is called preimplantation genetic testing (PGT).
• Transfer. During your next cycle, your doctor will place the selected fertilized eggs – now embryos – in your uterus by inserting a thin tube through your vagina and cervix (the opening to the uterus). With IVF, the number of embryos transferred depends on your age, the quality of the embryos, and your reproductive history. But generally, if an embryo has been PGT tested, only one will be transferred because those that are unlikely to implant or unlikely to result in a healthy pregnancy have been weeded out.

By the way, prenatal tests, such as cell-free DNA testing (noninvasive prenatal testing or NIPT),  amniocentesis or chorionic villus sampling (CVS), are still offered during pregnancy to check for genetic abnormalities.

Most fertility clinics offer non-medical sex selection, but you'll want to confirm it with the clinic you have in mind. Also iron out the cost (financially and in time) and steps involved so you can make an educated decision about whether the process is worth it to you.

If you're serious about trying one of these techniques for family balancing, you'll have to meet strict requirements. At some fertility clinics, you won't be eligible unless you're married and already have at least one child of the opposite sex you're trying for. And some clinics have age limits, but all will run hormone tests to see if you're still fertile.

Effectiveness

Preimplantation genetic testing is close to 100 percent accurate at determining the sex of the embryo. The IVF success rate depends on a number of factors, but for women younger than 35 using her own eggs, the success rate for becoming pregnant on the first try is almost 60 percent.

Pros of IVF with PGT

• If you do get pregnant, PGT ensures with almost 100 percent accuracy that you'll have a baby of the sex you desire.
• Following a PGT cycle, remaining embryos of both sexes can be frozen. These can be used in the future if you miscarry or decide you want more children. Frozen embryos have a success rate similar to fresh transfers, but the procedure is less invasive and significantly cheaper.
• PGT allows higher success rates during IVF, especially for older women. The percentage of live births per egg retrieval starts to decline significantly after age 35. Most IVF centers report higher success rates with PGT, since abnormal embryos are excluded.

Cons of IVF with PGT

• A single round of IVF with preimplantation genetic testing can cost more than $20,000. (Check with your insurance – some expenses may be covered.)
• The procedure is invasive, and having eggs removed from your ovaries can be painful.
• Fertility drugs can have uncomfortable side effects, including weight gain, bloating, swelling, and blurred vision.
• IVF procedures must be timed correctly, which often means you'll need to be in close proximity to your doctor for the duration of treatment.

Ericsson method

What it is

This technique, named for its founder Ronald Ericsson, aims to separate faster-swimming, boy-producing sperm from slower-swimming, girl-producing sperm. It's used in combination with artificial insemination (AI).

Effectiveness

The technique claims to be 70 to 75 percent effective, with more favorable results for conceiving boys than girls. Some independent studies have supported these claims, while others have contested them. One study of over 2,000 embryos from women undergoing IVF showed no significant improvement in the likelihood of one desired gender over another using this method.

How it's done

First, a sperm sample is poured on a gluey layer of fluid in a test tube. The fluid is liquid albumin, so the technique is sometimes referred to as albumin separation. All the sperm naturally swim down, but the boy-producing sperm tend to swim faster and reach the bottom sooner.

Once the fast and slow swimmers are separated, you're inseminated with the sperm that may help you conceive a baby of the sex you desire.

Pros

• Inexpensive compared to higher-tech methods
• Noninvasive
• Relatively safe

Cons

• There's no guarantee of success. Ericsson has published his own research and claims a success rate of approximately 75 to 80 percent, but evaluations of the test haven't been published by other fertility experts or proven independently.
• AI is not as effective as IVF, and it may take many cycles to achieve a pregnancy, depending on your age and fertility.

Cost

Approximately $600 to $1,200 per attempt

Availability

In the United States, this technique is only available through a handful of franchised clinics.

For more information

You'll need to contact fertility clinics or search online to find out which ones offer this service.

MicroSort (Flow cytometry)

Maybe you've heard of MicroSort, though it's not approved for use in the United States.

What it is

This technique involves staining the sperm with a fluorescent dye and then separating the male and female sperm cells using a flow cytometer. Once the sperm are identified, the preferred sperm can be placed in the uterus during ovulation using AI or IVF.

Effectiveness

In its initial clinical trial, MicroSort reported 90 percent effectiveness for female gender selection and 85 percent for male gender selection. But these numbers have not been conclusively confirmed independently.

How it's done

The sperm sample is washed and then stained with a fluorescent dye that attaches to the DNA in the sperm. The stained cells are passed through a laser and examined to see which shine brighter. The female sperm cells, because they contain slightly more genetic material than male sperm cells, will give off more light. The sperm carrying the X (if female gender is desired) or Y (if male gender is desired) chromosome are separated. The sorting takes about six or seven hours.

Pros

• Can be used for AI or IVF or can be stored for future use using cryopreservation.

Cons

• This method is not available in the United States.
• There is some concern that techniques that modify sperm may affect sperm quality. Researchers continue to study this.
• To use MicroSort, couples must have at least one child and use the technique for the underrepresented gender or be a known carrier of a chromosomal-linked disorder.

Cost

MicroSort costs about $3,200 per try.

Availability

MicroSort is not FDA-approved and is not available in the United States. It is still offered in Mexico, North Cyprus, Japan, Malaysia, Cambodia, Thailand, and Nigeria.

For more information

Learn more about this method at the MicroSort websiteOpens a new window.

At-home gender selection techniques

These low-tech methods are noninvasive and affordable, and you can do them in the privacy of your own home. All you need to do is chart your basal body temperature or use an ovulation calculator or ovulation test kit to determine when you ovulate, then time sex accordingly.

So what's the catch? They're not dependable. Still, it might be fun to try! Just keep in mind that the odds are 50/50 – don't be disappointed if your efforts don't work.

Shettles method

What it is

Timed intercourse on specific days of your cycle, using sexual position, depth of penetration, and female orgasm to enhance the probabilities.

Effectiveness

Shettles proponents claim the technique is 75 percent effective for choosing girls and 80 percent for choosing boys, but other experts are doubtful. Keep in mind that you always have about a 50 percent chance of conceiving a girl and a 50 percent chance of conceiving a boy.

How it's done

The theory is that sperm bearing a Y chromosome (for boys) move faster but don't live as long as sperm that carry X chromosomes (for girls). So, if you want a boy, the Shettles method contends you should have sex as close as possible to ovulation. If you want a girl, plan to have sex two to four days before you ovulate.

Pros

• Does not require drugs or invasive medical procedures
• Free or low cost
• Safe

Cons

• You must chart your basal body temperature or otherwise calculate your ovulation to estimate the best time to have intercourse.
• There's no guarantee of success.

Availability

Anyone can try it at home.

For more information:

Learn more about charting your basal body temperature and calculating ovulation.

Whelan method

What it is

Timed intercourse on specific days of your cycle.

Effectiveness

Elizabeth Whelan claims her technique is 68 percent effective for choosing boys and 56 percent effective for choosing girls, but many experts are doubtful. Again, you always have a 50 percent chance of conceiving a child of the sex you want.

How it's done

The Whelan method directly contradicts the Shettles method. The theory here is that the biochemical changes that may favor boy-producing sperm occur earlier in a woman's cycle.

So, if you want a boy, you should have intercourse four to six days before your basal body temperature goes up. If you want a girl, plan to have sex two to three days before you ovulate.

Pros

• Does not require drugs or invasive medical procedures
• Free or low cost
• Safe

Cons

• You need to take your basal body temperature every day to figure out when you're ovulating, or use other methods to calculate when you ovulate.
• There's no guarantee of success

Availability

Anyone can try it at home.

For more information:

Learn more about the signs of ovulation.

Gender selection kits

What it is

These at-home kits are based on the Shettles theory. Separate girl and boy kits include a thermometer, ovulation predictor test sticks, vitamins, herbal extracts, and douches that are supposedly intended to favor a specific sex.

Effectiveness

Kit makers claim a 96 percent success rate, but some medical experts say the manufacturer's claims have no scientific merit.

How it's done

You track your cycle by using the thermometer and urinating on the ovulation predictor test sticks. Following the Shettles method, you have intercourse two to four days before ovulation if you want a girl and as close as possible to ovulation if you want a boy.

The douche is intended to change the vaginal environment to make it more conducive for either an X-carrying sperm or a Y-carrying sperm to fertilize the egg. Vitamins and herbal extracts are also included to supposedly boost your odds of getting a child that is the sex of your choice.

Pros

• Does not require invasive medical procedures
• Convenient

Cons

• The success rate claimed by kit makers is questionable
• Douching is not recommended by doctors, and can actually lead to other problems like vaginal infections.
• Expensive

Cost

$199 for a 30-day kit.

Availability

Sex-selection kits are available online.

For more information

Learn more about sex-selection kits by visiting the GenSelectOpens a new window or Gender Selection KitOpens a new window websites.

Should I try sex selection?

This is a very personal choice based on your family's needs and desires. If you're eager to conceive but are concerned about a sex-linked genetic disease, for example, high-tech gender selection might be especially attractive to you. (Your healthcare provider and/or a genetic counselor can help you sort out the best path.)

If you're daydreaming about how nice it might be to have a girl – or a boy – this time around, perhaps you'll want to try less high-tech options. Or maybe you have your heart set on a boy or a girl for personal reasons and are willing to do whatever you can to make that happen.

High-tech sex-selection methods have stirred hot debate in the medical community. Some doctors think it's a great way to balance families, while others think we're heading down a dangerous path.

What is the opposition to sex selection?

Here are some of the concerns voiced by those who oppose sex selection:

• It may reinforce sex biases and sex ratio imbalances, especially in cultures where one sex is more highly valued. Even in the U.S., there is some evidence that the use of PGT shifts the sex ratio from about 105 boys per 100 girls to 110 boys per 100 girls. This may be in part because of increased selection of male embryos and in part because the procedure slightly favors male embryo survival.
• It has the potential to psychologically harm children – whether they were the desired sex or not. Children who are the desired sex may not behave in sex-specific ways expected by the parents, for example. Or the parents may be disappointed if the sex selection was unsuccessful.
• The destruction of excess embryos for the purpose of sex selection is unethical.

In a statement titled, The use of reproductive technology for sex selection for nonmedical reasons, ASRM states that "sex selection should not be encouraged for nonmedical indications." It also states, "The ASRM Ethics Committee recognizes that there are reasoned differences of opinion about the permissibility of these practices and does not have a consensus on the permissibility of these practices." They go on to say that clinics are encouraged to develop their own policies and are under no ethical obligation to provide or refuse these services.

Low-tech sex selection has not sparked the same controversy, probably because these methods are far from foolproof, and the assumption is that couples practicing them are investing less – both financially and emotionally – in their success.

Learn more:

• Gender prediction: Am I having a girl or a boy?
• Chinese gender predictor (for fun)
• When and how can I find out my baby's sex?
• Should we find out our baby's sex?