Edwards’ syndrome: frequently asked questions for pregnant women

Pregnancy is a whole new world of terms and concepts that you need to familiarise yourself with. Although mothers-to-be are keen for everything to go smoothly and for a healthy baby to be born, it is also important for them to know about the different abnormalities and diseases that may affect the foetus.

One of these irregularities is Edwards’ syndrome, a genetic deformity with a high death rate for live births. Luckily, this disease can be detected during pregnancy by performing specific tests. These are some of the frequently asked questions of pregnant women in relation to this syndrome.

What is Edwards’ syndrome?

Edwards’ syndrome, also known as trisomy 18, is a genetic alteration caused by the presence of three copies of chromosome no. 18. This irregularity is not very common, despite its presence in all races and geographic areas.

Edwards’ syndrome affects pre and post natal growth, which is why the weight of any babies born with this birth defect is usually below average. This alteration causes orofacial irregularities, such as a small mouth, ogival palate, short neck and ocular defects. It also affects the rest of the body, with limb defects, kidney abnormalities and cardio-vascular problems.

Is Edwards’ syndrome serious?

Although this genetic disorder is included in the group of uncommon disorders, in that it affects between 1/6,000 – 1/13,000 of live births, Edwards’ syndrome is considered to be serious because of its high death rate: 95 % of new-born infants with this abnormality die within a year of their birth.

Can Edwards’ syndrome be detected during pregnancy?

Pregnant women can undergo several prenatal tests to detect this syndrome. There are several kinds of reliable test although they do vary in risk. They are particularly recommended for women over the age of 35, as this is the age from which there is a greater chance that the baby will be born with this syndrome, or for pregnant women whose previous children have trisomy 18.

One of the most frequent tests is the amniocentesis, consisting of an invasive test in which a sample of amniotic fluid is extracted. Although this test, which is usually carried out as of week 15, is reliable, the amniocentesis also involves risks both for the mother and the baby.

On that basis, there are other alternatives, such as the non-invasive prenatal test NACE, which detects these abnormalities from a single blood sample. As of week 10, this is also the week in which Down’s syndrome or Patau’s syndrome can also be detected. As it is not invasive, it avoids risks such as an infection of the placenta or miscarriage, two risks related to the amniocentesis.

When there is a history of Edwards’ syndrome, the best option before pregnancy would be to undergo a PGS (Preimplantation Genetic Screening); this analysis can be performed on future mothers who resort to in vitro fertilisation and makes it possible to select genetically normal embryos and provide peace of mind during pregnancy.