Prenatal Diagnosis

by | June 23, 2020

All pregnant women are informed about fetal diagnosis in connection with enrollment at the maternity care center.

In Sweden, all pregnant fetal diagnostics are offered. An ultrasound examination is often performed at the beginning of pregnancy. The mother can also provide blood samples that, along with the ultrasound, are used to calculate the probability of certain chromosome abnormalities. All fetal diagnostics are optional.

Prenatal Diagnosis

What is it possible to find out?

With an ultrasound examination you can find out the following:

  • If there is more than one fetus.
  • How the fetus grows.
  • Amount of amniotic fluid in the uterus.
  • How far you have come in pregnancy.
  • If the fetus has certain abnormalities or diseases.
  • How the placenta works and where it sits.

It is possible to find out what gender the fetus has. However, this does not care if there is no medical interest in knowing it. The pregnant woman may not know it even if she asks.

The ultrasound sometimes needs to be combined with other fetal diagnostics. You can find out about fetal health through fetal diagnosis, but there is much that cannot be seen or checked.

Information requirements

The pregnant woman who desires fetal diagnosis is informed by staff at the maternity care center:

  • What investigations you can do.
  • The risk associated with these studies.
  • How the tests are performed.
  • What answers they can give.
  • How likely it is to make some discoveries.

What surveys are available?

You need a referral to make fetal diagnosis. It is usually a midwife who writes the referral and makes a visit for diagnostics.

The following studies may be relevant:

  • Early ultrasound (weeks 11-14):
    • Can detect development defects or deformities to a small extent
    • Used to look for signs of Down syndrome
    • There are rare diagnoses on the basis of such a study, you can get a suspicion in a certain direction
  • Ultrasound (weeks 16-20):
    • Are all pregnant offered to determine the duration of pregnancy, determine that the fetus is alive, count the number of fetuses and examine the fetal anatomy
    • Can detect developmental abnormalities and deformities
  • Double test: Combined ultrasound and biochemical screening, KUB (week 11-14):
    • Blood samples from the mother are combined with early ultrasound
    • The test is harmless to the fetus and the mother
    • The test can be used to assess the likelihood of having a child with chromosomal abnormalities that results in Down syndrome (trisomy 21), Pataus syndrome (trisomy 13) or Edwards syndrome.
    • If the test detects a high probability of having a child with the above chromosome abnormalities, you can continue with amniotic fluid or placental test to obtain a safer answer
    • If the test shows a medium probability of having a child with the above chromosome anomalies, you can proceed with NIPT to more accurately assess the probability
  • NIPT (Non-Invasive Prenatal Testing) can be done from pregnancy week 10 but is usually offered from week 12 or 13:
    • NIPT is a blood sample from the mother where one can assess the fetal DNA
    • NIPT is a test that is considered to be very reliable and also risk-free
    • However, if NIPT suspects that the fetus has a chromosomal aberration, it is necessary to do a placenta or amniotic fluid test to get a definitive answer
  • Amniotic fluid test (after pregnancy week 15):
    • A thin needle is inserted into the uterus through the mother’s abdomen and a small amount of amniotic fluid is removed
    • The sample can be used to detect chromosome anomalies
    • The sampling itself involves a risk of miscarriage, about 1 in 200 (0.5%) due to the sampling
  • Placenta sample (after pregnancy week 10):
    • A small tissue piece of the placenta is obtained through a thin needle via the abdomen
    • The sample can be used to detect chromosome anomalies
    • The sampling itself involves a risk of miscarriage, about 1 in 200 (0.5%) due to the sampling

What can the answers to the survey lead to?

  • It is important to remember that most samples can only say something about the likelihood of having a child with a disease or developmental defect.
  • There is a widespread misconception that normal findings are the same as having a healthy child:
    • Unfortunately, the surveys we have available today do not fully guarantee that the child is fully healthy
  • In most cases, you will be told the probability that the child has a certain condition. It can be difficult to decide what is the best choice.
  • You have the right to in-depth information and guidance.

Get help

It is important to have as much information as possible, but also to have the opportunity for call support. Sometimes you may need help in making difficult decisions.

It can be difficult and difficult to decide on examinations or test answers. It can be good to talk to a curator, for example. The call support is usually offered in the same place as where the fetal diagnosis is made. Call support is free of charge and both parents are entitled to this support.

If you do not speak Swedish, you may have the right to get help from an interpreter. Even if you have a hearing impairment, you may have the right to receive interpreting assistance.