What It Is

ChromoMap is a screening test performed during pregnancy that can identify if there is an increased risk for your baby to have certain types of chromosome abnormalities. Many individuals find it helpful to discuss the results of this type of testing with a genetic counselor—someone who is specially trained in helping people understand genetic information and the impact it may have on them and their families.

Key Points

  • All pregnant women/couples have some risk of having a child with a chromosome abnormality. Certain factors can increase this risk, including maternal age and ultrasound findings.
  • The ChromoMap test can screen for chromosome abnormalities, including Trisomy 21 (Down syndrome), Trisomy 18 (Edwards syndrome), Trisomy 13 (Patau syndrome), other autosomal aneuploidies, sex aneuploidies, and microdeletion syndromes. Your doctor may have requested testing for some or all of these conditions.
  • A normal result reduces the risk for a pregnancy to have a chromosome abnormality, but it does not completely eliminate this risk.
  • An abnormal result increases the risk for a pregnancy to have a chromosome abnormality, but it does not mean that it is certain the baby has the condition.
  • This testing only looks for certain chromosome abnormalities. It does not test for all possible chromosome anomalies nor does it assess the risk for birth defects, intellectual disability, or genetic syndromes.
  • If your doctor orders testing for sex aneuploidies, the ChromoMap screen will identify fetal sex. For twin pregnancies, the test can only determine presence or absence of the Y chromosome.
  • Typically when ChromoMap is performed on a twin gestation, the findings would apply to both twins if the pregnancy is monozygotic (i.e. if the twins are identical). If dizygotic twinning is present (i.e. if the twins are fraternal), the result may apply to one or both twins.

What to Expect

CooperGenomics’ genetic counselors are highly trained board-certified medical professionals with Master’s degrees in Human Genetics and Genetic Counseling. If your doctor requests that you have genetic counseling for your ChromoMap screening results, here is what you can expect:

  • Appointments are conducted over the phone and typically take about 30-60 minutes.
  • Results from genetic testing can be complex and confusing; understanding them doesn’t have to be. Our genetic counselors will help you navigate your results and discuss how they may impact your reproductive decisions. If your pregnancy is identified to be at an increased risk to have a chromosome abnormality, the genetic counselor will review details about the condition for which there is an increased risk, the risk for the baby to be affected, and additional prenatal testing options to obtain more information regarding whether the baby is affected, such as CVS or amniocentesis.
  • Your genetic counselor will ask you questions about your pregnancy and medical history, and the medical history of your family members to determine if there are any additional health risks beyond your ChromoMap results.
  • After your genetic counseling session, you and your doctor will receive an email with a copy of your results as well as a detailed letter summarizing everything discussed during your session.

How to Prepare

  • Try and choose a time where you can be somewhere quiet, private, and focused on the medical information the genetic counselor is providing. If possible, please do not schedule the appointment while you are at work, driving, or otherwise pre-occupied. If possible, you may want to select a time when your partner can join the call as well, though this is not required.
  • Discuss what information you want regarding the test, results, risks, and further testing options with your partner before your appointment.
  • Write down all of your questions beforehand so you don’t forget to ask us about any specific concerns you might have.
  • Obtain details about you and your partner’s family history. For example, have family members experienced any of the following?
    • Three or more miscarriages
    • Born with a birth defect such as a heart defect, clubbed foot, or cleft lip
    • Delayed development
    • Intellectual disabilities or autism
    • Cancer diagnosed before age 50
    • A hereditary condition
  • If for any reason you need to cancel or reschedule your appointment, please contact our team at least 24 hours prior to the scheduled time.

Visual Aids

Because genetic counseling is performed over the phone, you may find it helpful to reference the following visual aids before, during, or after your session. Please inform your genetic counselor at the time of your appointment if you have these available so they can refer to them during your discussion.

Inside Cells are Chromosomes

Inside cells are chromosomes. Chromosomes X and Y determine whether you are female (XX) or male (XY).

Non-invasive Prenatal Screening (NIPS)

NIPS tests the mother's blood for the baby's DNA. This test looks for specific chromosome abnormalities and can also determine fetal sex.

Chorionic Villus Sampling (CVS)

Chorionic Villus Sampling (CVS) can be performed between 10-13 weeks of pregnancy, and is an invasive test.


Amniocentesis testing can be performed after the 15th week of pregnancy. Due to its invasive nature, it does carry a small risk of miscarriage, but the risk is lower than that of CVS.