Maastricht University. Netherlands: The composition of the culture mediums used to grow human embryos during IVF treatment affects the birth weight of newborns.
The dissertation by Ewka Nelissen, a gynaecologist in training in Maastricht and Sittard, is the first to reveal that the composition of culture mediums can result in significant differences in human embryos. Previous non-IVF studies have shown that low birth weight babies were more likely to develop illnesses later in life. Whether the same applies to children conceived through IVF remains unknown, given that the oldest IVF children are under the age of forty. The results, however, are concerning. Nelissen therefore recommends further research and more transparency by manufacturers into the composition of their culture mediums.
In 2012, one in thirty-seven babies were conceived through in vitro
fertilisation (source: Netherlands Association for Obstetrics and
Gynaecology). Artificial insemination requires culture mediums supplied
by commercial manufacturers. More than twenty different culture mediums
are available worldwide, the composition of which are largely unknown.
‘These culture mediums are patented,’ explains Nelissen, ‘which makes it
hard for doctors and clinical embryologists to compare them. The
manufacturers regularly change the composition of their mediums, which
makes it difficult to conduct thorough scientific research on the
quality.’
In the four years that Nelissen has worked for the IVF
clinic in Maastricht, from 2006 to 2010, it was discovered that babies
conceived using one type of culture medium weighed 112 grams less than
babies conceived using a different medium. ‘We don’t know how this will
affect these children in the long run because the oldest IVF baby is
under the age of forty. Follow-up research has revealed a difference in
birth weight up to the age of two.’ An on-going study known as the
MEDIUM KIDS study is being conducted by MUMC+ to track the health of
these children until the age of nine. The study also takes into account
height and various aspects of metabolic syndrome, such as blood pressure
and vascular function.
Rocky start
Normally,
an embryo is placed in a culture medium for two to three days before
being implanted into the uterus. ‘This relatively short period appears
to impact the pregnancy,’ Nelissen explains. Numerous studies have
revealed that the likelihood of developing a chronic disease later in
life, such as cardiovascular disease, diabetes or stroke, is linked to
poor growth in the uterus and a lower birth weight. ‘We suspect that IVF
children who were conceived in a less favourable culture medium under
less favourable circumstances during early pregnancy are more likely to
develop health problems later in life.’ Nelissen is therefore calling
for further research into the effects of culture mediums on poorer IVF
outcomes as well as better clinical safety monitoring. ‘The
manufacturers are legally required to conduct a pre-clinical trial on
animals and then monitor the results in the clinic. This is not being
done or not being done well.’
Nelissen will defend her dissertation entitled, ‘In vitro culture of human embryos: effects on fetal development and the role of the placenta’, on Thursday 26 February at 16.00 at Maastricht University.