FAQ – X or Y – Science


What is the science behind X or Y Early Gender Test?

What is the science that makes X or Y Early Gender Detection possible? The answer lies in DNA research, which has rapidly advanced our understanding of life. DNA science has demonstrated that there is fetal DNA in an expectant mother’s blood. In a natural process, fetal cells die and pass into the mother’s bloodstream. As these cells break down, their DNA is released into the mother’s own circulatory system. In other words, the cells decompose and free DNA is released into the mother’s bloodstream. And by using a small sample of the mother’s blood, we can determine, with ultra high accuracy, if there is Y-specific chromosomal DNA. If we detect Y-specific chromosomal DNA, the fetus is male. If there is no Y-specific chromosomal DNA, then the fetus is a female. Remember, females have two X chromosomes, while males have one X and one Y chromosome.

In summary, fetal DNA in a mother’s blood makes this scientific process possible. Next, discover why it matters here.

If you’re ready to take the test, you can order here.

How accurate is X or Y?

X or Y Early Gender Test is +98% accurate based on controlled laboratory setting studies for ideal samples starting at 9 weeks pregnancy and older. The company has implemented a program that monitors our accuracy rate and service quality on an ongoing basis. You may be offered the opportunity to participate in our ongoing quality monitoring program during your ordering process or after your testing is completed.

Order your kit here.

Are there factors that affect the accuracy of X or Y?

There are several factors which may affect the accuracy of a X or Y result. Some of these factors can be controlled and minimized by the customer and/or laboratory while others are independent factors that cannot be influenced.

Factors which could affect the accuracy of X or Y and which can be minimized:

  • Not following the directions carefully: improperly handling kit components, improperly washing hands, and not sanitizing the collection area
  • Contaminating the sample: allowing males to handle kit contents or assisting with sample collection.
  • Taking the test earlier than 7 weeks post-conception (if you wish to test earlier at 6 weeks post-conception, sign the authorization waiver for the ultra sensitive X or Y test)
  • Having a recent transfusion, miscarriage or abortion
  • Providing an insufficient blood sample
  • Leaving the sample in a hot environment

Factors which could affect the accuracy of X or Y which cannot be controlled:

  • Having a bone marrow transplant from a male donor, blood transfusions, miscarriages or abortions: our technology can detect DNA from previous male pregnancies or from male blood/marrow donors as contamination in most cases. However, there may be instances where the accuracy of our test is affected by any of these conditions.
  • Miscarriage: Women who have recently experienced a miscarriage must wait at least 3 months before they can use X or Y. If it has been at least 3 months since the miscarriage, then you are eligible to order X or Y.
  • Having naturally low levels of fetal DNA: studies have determined that up to 2.8% of women have naturally low levels of fetal DNA. While X or Y is much more sensitive than the methods used in those studies, there may still women whose levels of fetal DNA are too low even for our test to detect. This is a difficult statistic to measure but we anticipate it is less than 2%.
  • Vanishing Twin: some pregnancies begin with two (or more) fetuses but very early in the pregnancy, one of the fetuses terminates. In many cases, this occurs without the woman’s knowledge. If the “vanishing twin” is male and the remaining fetus is female, the results of X or Y may be incorrect.
  • Previously pregnant with a boy: in very rare cases (less than 1%), fetal cells may remain in the mother’s body several years after birth. Our technology can detect some of this DNA as a form of contamination, however, there may be cases where the accuracy of the test may be affected by this rare occurrence.
How does X or Y compare to an ultrasound, CVS, and amniocentesis?


Performed at:




X or Y



>7 weeks after conception
(9 weeks after day-one of your last menstrual period). Test can be taken earlier with the signing of waiver.

(Prices may vary due to shipping country and optional expedited lab service)

+98% (in controlled laboratory setting studies)



Physician’s Office/  Hospital

~18-20 weeks






~14-20 weeks



CVS (Chorionic Villus Sampling)*



~10-13 weeks



*Carries some risk to the mother and/or fetus

Does X or Y replace an Ultrasound?

No, X or Y does not replace an Ultrasound. Ultrasounds are used for medical and/or health reasons and not just for checking the sex of the baby. Studies have shown that ultrasounds have an accuracy rate of less than 85% before 12 weeks and are greater than 98% accurate at 21 weeks post-conception. Because it can take from five to six months to tell the gender of your baby using the ultrasound, we offer you X or Y Early Gender Test.

If you are EXCITED to know the sex of your baby, X or Y Early Gender Test is for you! X or Y Early Gender Test is a unique DNA-based test that tells you whether you are having a boy or girl! (results starting at 9 weeks after the start of your last menstrual period, approximately 7 weeks post-conception)

X or Y Early Gender Test is a service providing information that has no impact on the health of the mother or the baby. X or Y Early Gender Test makes no medical diagnoses, recommendations, treatments, or medical or health claims.

You can order your kit here.

What is Chorionic Villi Sampling?

Chorionic villi sampling (CVS) is a prenatal test that can detect genetic abnormalities such as Down’s syndrome. Unlike amniocentesis, CVS does not screen for neural tube defects. It is performed earlier than amniocentesis—between the 10th and 12th weeks of pregnancy.  In CVS,  a catheter or thin needle is inserted into the womb to extract some of the chorionic villi—cells from the tissue that will become the placenta. The chorionic villi contain the same chromosomes as the fetus.

Why would I take this test?

You may want to have the CVS test if there is an increased risk of chromosomal or genetic birth defects, and if you would like test results as early in pregnancy as possible. The test is not routinely offered to all pregnant women because the test carries a small risk of miscarriage, and possibly other complications. Also, CVS usually isn’t recommended if a woman has bleeding or spotting during the pregnancy.

CVS may be offered because of:

  • Advanced maternal age. The risk of bearing a child with certain chromosomal birth defects increases as a woman ages. Prenatal testing is offered if a woman will be 35 or older at the time of delivery.
  • A previous child or pregnancy with a birth defect. A woman may be offered CVS or amniocentesis during subsequent pregnancies if she already has had chromosomal abnormality or genetic birth defects diagnosed in a prior pregnancy or child.
  • Family history that indicates the baby may be at increased risk of inheriting a genetic disorder. Prenatal diagnosis is possible for virtually all chromosomal disorders, but not all genetic ones.

How is CVS performed?

In a private exam room, your vagina and cervix are thoroughly cleansed with an antiseptic. Then, with an ultrasound as a guide, your doctor inserts a thin tube through your vagina and cervix (transcervical CVS) to the villi, and uses gentle suction to remove a small sample. No anesthetic is required.

The physician may choose an alternate method to reach the chorionic villi by inserting a needle through the abdominal wall (transabdominal CVS), also using ultrasound guidance. Both forms of CVS have found to be equally safe, although the transabdominal CVS is recommended for women with a tipped uterus because the risk of miscarriage is higher if done transcervically.
After the procedure, the fetal heartbeat is checked with ultrasound before you leave the examination room. You may experience lower abdominal cramping following CVS; or some bleeding or spotting, which ordinarily stops within a few days. If you have these symptoms, tell your doctor.

Studies suggest CVS may be slightly more likely to cause miscarriage than amniocentesis. For women with an anteverted uterus, there is no increased risk of miscarriage. Complication rates from CVS have been shown to be lower among physicians who perform this test more frequently. Before consenting to this test, check with your doctor and determine how often he/she has performed this test.

There has been some concern that the test itself may be associated with limb deformities. However, many geneticists believe that CVS performed between the 10th and 12th weeks of pregnancy does not increase that risk.

How accurate are the CVS results?

Test results have a greater than 99 percent accuracy rate in ruling out certain chromosomal birth defects and specific genetic problems. However, the test is slightly more likely than amniocentesis to give inconclusive results.

Does a negative CVS result mean a baby will be born healthy?

More than 95 percent of the high-risk women who have any prenatal diagnosis receive reassuring news that their unborn babies do not have a disorder for which they were tested. However, no prenatal test can guarantee a healthy baby, since only some birth defects can be ruled out before birth. Three to four of every 100 babies have a birth defect.

Can birth defects diagnosed with CVS be treated?

Advances in prenatal treatment make it possible to treat some birth defects before birth. However, physicians are able to diagnose more birth defects than they are able to treat prenatally. If a fetus has a condition for which prenatal treatment is not possible, prenatal diagnosis may help parents to decide whether to continue the pregnancy or prepare emotionally for the birth.

What is Amniocentesis?

Amniocentesis is a prenatal test that allows you and your practitioner to gather information about your baby’s health and development from a sample of your amniotic fluid. This is the fluid that surrounds your baby in the uterus. The test is most commonly done when a woman is between 15 and 20 weeks pregnant to determine whether the baby has genetic or chromosomal abnormalities, such as Down syndrome. Not all women choose to have this test, in part because it carries a small risk of miscarriage.

Other reasons that you may need to have amniocentesis include:

  • To check on the well-being of your baby if you have a blood sensitization, such as Rh sensitization. This is a complex condition that can occur if your blood is a different type than your baby’s.
  • To determine whether your baby’s lungs are mature enough for an early delivery if you appear to be in premature labor or require an early delivery for any reason.
  • To diagnose or rule out a uterine infection if your water has broken prematurely or your practitioner has any other reason for suspecting you have one.

Which birth defects can amniocentesis detect?

Amniocentesis can identify several hundred genetic disorders, including some of the most common:

  • Nearly all chromosomal disorders, including Down syndrome and Edward’s syndrome. The test is more than 99 percent accurate in diagnosing these conditions. An ultrasound, a combined first-trimester screening, or a multiple marker test may indicate whether your baby is likely to have these problems, but only amniocentesis can tell you for sure.
  • Other genetic disorders such as cystic fibrosis, sickle cell disease, Tay-Sachs disease, and Huntington’s disease. Neither the multiple marker test nor ultrasound will pick up these problems. Only amniocentesis can provide the information needed to diagnose them in the womb.
  • Neural tube defects such as spina bifida* and anencephaly*.

More than 95 percent of the high-risk women who have amniocentesis receive good news from the results. Only about 5 percent will be found to have a baby with a problem. Amniocentesis doesn’t detect every birth defect, however. A cleft lip or palate, for example, won’t show up on the test.

Is amniocentesis appropriate for me?

Although most centers will do an amnio for any pregnant woman who wants one, the procedure isn’t offered routinely to all pregnant women because it carries a small risk of miscarriage.  It’s usually only offered to those found to have a somewhat increased risk of having a baby with a chromosomal or genetic defect.

You may be in this category if:

  • You’ll be 35 years old or older on your due date. The risk of having a child with a chromosomal defect rises as a woman ages. The chance that you’re carrying a baby with Down syndrome, for instance, is about one in 270 when you’re 35 years old – compared to 1 in 1,250 when you’re 25.
  • You’ve had another test, such as a multiple marker screen, a nuchal fold scan, or a “combined screening,” that indicated your baby is at a higher risk for a problem. If this is the case, you may first have a detailed ultrasound scan to look for physical signs of Down syndrome and other defects. If the ultrasound shows that there’s still cause for concern, you may want to have an amniocentesis for a definitive diagnosis.
  • You’ve previously been pregnant with a child with a birth defect.
  • You or your partner has a chromosomal abnormality or genetic disorder or a family history that puts your child at increased risk for genetic problems. Or you and your spouse are both carriers of a recessive genetic disorder such as cystic fibrosis or sickle cell disease.

What are the risks of the amniocentesis procedure?

In deciding whether to have this test, you’ll need to weigh your desire to know about your baby’s condition against the slight risk that the test will lead to a miscarriage. You’ll definitely want to discuss your options with a genetic counselor so that you understand all the risks and benefits of your choices. For example, you may decide to have a combined first-trimester screening or a multiple marker test first to gain more information about your risk for certain problems.

There are many reasons to want to know about your child’s condition. Even if you would never terminate a pregnancy for any reason, knowing in advance that your baby will have special needs allows you to prepare for the challenges you might face. You might want to switch to a better-equipped hospital with specialists, for example. Knowing what’s going on with your baby allows your medical team to monitor your pregnancy as needed and to bring a neonatologist or pediatric surgeon on board to prepare to help your baby after delivery. And a few problems can even be treated in utero, such as biotin dependence and MMA (methylmalonic acidemia), both life-threatening, though extremely rare, body chemistry disorders.

That said, you’ll want to consider the small risk that the procedure may cause you to miscarry. According to the Centers for Disease Control and Prevention (CDC), the risk of miscarriage from amniocentesis is between one in 200 and one in 400, depending on the skill and experience of the doctor performing it. You’d also have a slight risk of uterine infection in the days following the procedure (less than one in 1,000), which can sometimes lead to miscarriage. These are all things you should discuss with your partner, your practitioner, and a genetic counselor.

Is there any way to reduce the risks associated with amniocentesis?

The more times the physician who does the amnio has performed the procedure, the lower your risk of complications. Ask your practitioner or genetic counselor to refer you to a physician with plenty of experience, preferably one who does at least 50 amnios a year.

You’ll also want to make sure that an experienced registered diagnostic medical sonographer provides continuous ultrasound guidance during the procedure. This greatly increases the chances that the physician will be able to obtain enough fluid on the first try and avoid having to repeat the procedure. And when continuous ultrasound guidance is used, injuries to the baby from the amnio needle are very rare.