In-Vitro Fertilisation (IVF)
In vitro fertilisation (IVF) is the infertility treatment during which the patient’s oocytes are fertilised outside her body, in a laboratory, under controlled laboratory conditions.
To achieve this, the patient follows a medical treatment aiming to stimulate the ovaries and help them produce many oocytes. Then, at the right moment, oocyte retrieval is performed, to be followed by oocyte fertilisation in the laboratory; fertilisation is carried out by embryologists using the man’s sperm sample. Fertilised oocytes are cultured in appropriate culture media and grown into embryos. After 2-5 days, the embryos are transferred back into the woman’s uterus (embryo transfer) and 14 days after oocyte retrieval, a pregnancy test is carried out in order to find out whether a pregnancy has been achieved.
The health of the children born following assisted reproduction treatments
One of the first questions that assited reproduction treatments, such as IVF, have given rise to, concerned the health of the children born following such treatments. Louise Brown, the first child born following an IVF treatment, in 1978, has become a mother herself, without any assisted reproduction treatment.
For the last 30 years, researchers have been collecting data about the health of these children, primarly focusing on the incidence rate of congenital abnormalities (registered at birth). Congenital abnormalities are - usually mild - embryonic malformations, which can be detected with an ultrasonogram during pregnancy, i.e. before the child is born. In the general population, the congenital abnormality rate is estimated at 1 – 4%. The question is whether the incidence rate of congenital abnormalities among children born following IVF is increased and if so, how much.
It is important to stress that, besides being premature and with low birth weight, twins (or triplets etc.), regardless of how they have been conceived (naturally or following a fertilisation treatment), have increased congenital abnormality rates. In other words, a multiple pregnancy constitutes a risk factor for congenital abnormalities. Many of the pregnancies achieved after assisted reproduction treatments are multiple (usually with twins and more rarely with triplets etc.). One of our aims at “gennima” is to reduce the multiple pregnancy rate; for that reason, we transfer a smaller number of top quality embryos. Studies do not show any difference in the congenital abnormality rate in naturally conceived twins versus those conceived with the aid of an assisted reproduction treatment.
As for single pregnancies, recent studies (see relevant articles below) report a slight increase in the congenital abnormality rate among children born following an assisted reproduction treatment, mainly in the cardiovascular and the gastrointestinal system. However, researchers note that this may not be due to the treatment techniques, but to the parents’ infertility itself. In fact, they stress the need for further studies, including large numbers of participants, so as to clarify that matter.
‘Assisted reproductive technologies and the risk of birth defects – a systematic review’
Hansen M et al 2005 Human Reproduction 20(2):328-338
‘Assisted reproductive technology and major structural birth defects in the United States’
Reefhuis J et al 2009 Human Reproduction 24(2):360-366
In the U.K., the authority that controls the operation of the assisted reproduction centres, called HFEA (Human Fertilisation and Embryology Authority), has taken a stand on that matter, so as to reassure the public.
According to the latest announcement of HFEA (March 2009), the percentage of children born with congenital abnormalities in Europe is low (2%). Researchers who claim that assisted reproduction treatments trigger an increase in the congenital abnormality rate, report that the percentage reaches 2.6% (versus 2% in the general population); this rate is also low.
Until now, studies cannot definitely tell whether this increased rate is due to the assisted reproduction treatments or not. There are more factors to which the increase could be attributed, such as the infertility causes, the parents’ age or other unclear factors. There are no more reliable data on that matter yet. HFEA, as well as the relevant responsible authorities worldwide, study all latest data in scientific research and inform the public.
Please read below the announcement of HFEA:
Today, more than 30 years after Louise Brown was born, millions of healthy children have been born all over the world following assisted reproduction treatments.