Latest update: 10/05/2017

Assisted reproductive treatment (ART) and PGD: ICSI

As soon as the PGD test is ready, you will come again for a consultation with the genetics doctor and the fertility gynaecologist. The latter will prescribe a medically assisted fertilisation treatment (IVF with ICSI, see below).
Then follows the interview with the fertility counsellor, who will go through the prescribed treatment schedule with you.


IVF/ICSI in a nutshell

With in vitro fertilisation the egg is not fertilised in the fallopian tube by the sperm cell, but outside the woman’s body, in a plate in the laboratory (‘in vitro’ means ‘in glass’).
In PGD we always use ICSI as the fertilisation technique, that is to say we inject one sperm cell into each egg.
Then the plate goes in an incubator that imitates the conditions of the uterus as closely as possible.

We briefly go through the sequence of steps of IVF/ICSI treatment. (You can find a full description of the treatment on

Your natural menstrual cycle is temporarily replaced by a medically-controlled cycle. At the same time you are given hormones to stimulate the ovaries. The intention is to get as many eggs to develop as possible.

Important - please follow instructions

During the IVF treatment there is a small risk of ovarian hyperstimulation, in which fluid accumulates in the abdominal cavity. Sometimes hospitalisation is necessary to treat this problem. We therefore strongly advise you to follow the instructions of the fertility doctor and the DM [daily patient monitoring] exactly. After all, this team is striving for a maximum number of good-quality eggs with a minimal risk of ovarian hyperstimulation.

Important - do not have unprotected sexual intercourse

As a PGD patient you were asked at the start of the test development to stop having unprotected sexual relations. This is to prevent you getting pregnant naturally, without the chance of carrying out a genetic test on the embryo.
That request is even more important in this ‘stimulated’ period: from the week before up to one week after the egg retrieval we ask you not to have unprotected sex under any circumstances.


Using blood tests we monitor when we can expect the ovulation. Immediately before this we insert a fine, hollow needle into the ovaries and collect the mature eggs. We call this egg retrieval, a procedure that requires a stay in hospital during half a day.

Mandatory screening for hepatitis B and C, HIV and syphilis

In accordance with the Belgian Act on tissue banks the screening for hepatitis B and C, HIV and syphilis needs to be repeated every three months.
Before the start of every treatment we need to know the latest results of the infection tests of every patient who provides (reproductive) material (eggs, sperm, embryos).


Fertilisation of the eggs via ICSI

For the fertilisation we use ICSI: the injection of one sperm cell into each egg. This is because this fertilisation technique provides the most embryos and avoids problems in the execution of the genetic test on the embryonic cells: of all eggs collected and fertilised ninety percent develop into an embryo.

The embryo biopsy

A biopsy consists of the removal of small amounts of material from the embryos that have developed in vitro. This provides us with two options

Option 1
On day three after fertilisation we remove one (or two) cell(s) for genetic analysis. While the diagnosis is being made on the removed cell(s) the development of the embryos from which the biopsy was taken continues in the incubator, until day five.

Option 2
The introduction of new techniques has recently made it possible to perform the genetic diagnosis only on day five after fertilisation. With this method we remove a small piece of trophectoderm from the developing embryos, which gives us more cells hence more DNA material.
Because it takes more than twelve hours for us to analyse that material (and it is better not to return embryos later than day 5 or 6), we freeze the biopsied embryos.

Post-retrieval analysis: possible status of each embryo

healthy’ for the genetic defect tested for and of good morphological quality;
  • ‘healthy’ for the genetic defect tested for and of poor morphological quality;
  • embryo displays the tested defect and is morphologically of good or poor quality;
  • In the case of HLA typing: HLA-compatible embryos versus ‘healthy’ but not HLA-compatible; 
  • no diagnosis reached.
Embryos that are genetically healthy and of good morphological quality are eligible for return to the uterus. This procedure is called embryo transfer and is best done in a short hospital admission.

Option 1 & 2– after biopsy on day 3

We know the result of the genetic analysis at day five of embryo development.

  • Either one or two selected embryo(s) are returned to the uterus in the current cycle and the supernumerary embryos are frozen.
  • Or all embryos are frozen for transfer in a later, non-stimulated cycle.


Option 2– after biopsy on day 5
All embryos are frozen for transfer in a later, non-stimulated cycle.

Which embryos

  • Only embryos that have been found to be normal after the genetic analysis are returned to the uterus.
  • Embryos that have been found to be abnormal or about which the genetic analysis did not give sufficient information, are not considered for transfer. In the exceptional case that we do transfer such an embryo, you will sign a separate consent form for that purpose.

How many embryos?

  • We put one or two – or sometimes three – unaffected embryos back in the uterus. 
  • That number is regulated by the legal guidelines on IVF. Determining factors are your age (the woman) and how many treatment cycles you have had in total.
  • But the quality and the genetic status of the embryos will naturally also play a role, as well as the number of available embryos. 
We have already seen that it is possible to freeze all the resulting embryos for return to the uterus in a later cycle.
But even if we return one (or two) embryos in the current cycle, we can freeze supernumerary embryos of good quality. If you do not become pregnant at the first attempt or later you want another child, then we can use these preserved embryos in a following cycle.
You decide what should be done with any supernumerary embryos (to freeze or not to freeze). You will establish that in a contract before the start of your treatment.
See also ‘Practical details’.

Approximately twelve days after the retrieval we perform a pregnancy test on a blood sample.
You can also get your general practitioner to take the blood sample and get it analysed by a laboratory of his or her choice. Of course you must let us know the result.
In other words, in approximately two weeks you will know whether a returned embryo has implanted in the uterus and whether you are pregnant.

If you are not pregnant…

You will get a follow-up appointment with your fertility gynaecologist for an analysis of your treatment and to discuss further possible investigations and treatment.

If you are pregnant…

We will schedule another ultrasound check, six to seven weeks after the embryo transfer.
You can also get this check done elsewhere, but again we ask that you pass on the results to us.
After this we schedule a further consultation in the PGD clinic to discuss your pregnancy. At that stage we will ascertain whether you want a prenatal diagnosis (chorionic villus sampling or amniocentesis) as a check-up.