Tuesday, 27 May 2014

How can we reduce health risks for babies born from IVF treatment? Time to act

A recent study from Australia found that, compared with women who conceived naturally, women undergoing IVF were at significantly higher risk of having a premature, severely underweight or stillborn baby or one which dies within a few weeks of birth.

The effects were also found, although to a lesser extent, in ICSI cycles. Overall there was a 2 to 5 fold increase in these complications when babies were conceived following IVF. Some of these facts were already known from other studies, but what was revelatory was that conceptions following implantation of a frozen embryo had a much reduced incidence of complication. For example a baby born after IVF was over half a pound lighter than a spontaneously conceived baby, but this did not apply in those babies born after frozen embryo transfer. 

In response to this the authors of the paper postulate that implantation of the embryo transferred in a fresh stimulated IVF cycle can be compromised by high levels of oestrogens. These high levels are derived from the use of stimulating drugs, used to boost the number of eggs produced, and which do not occur when a frozen embryo is transferred into an un-stimulated or natural cycle. So now we have proof that avoidance of high oestrogen levels, common practice in conventional stimulated IVF cycles, will not only reduce health risks for the mother but for the baby as well. 

As someone who has championed mild and natural IVF for many years I feel vindicated by these findings. The association of frozen embryo transfer cycles and better outcome has been reported before this, and prompted discussion as to whether freezing all embryos for later transfer should become routine if conventional stimulation is used. However this is an expensive and unnecessary option. The logical way to reduce the health risks associated with high oestrogen levels in IVF, for mothers and babies, is the adoption of mild and more natural IVF protocols. Babies born following modified natural cycle IVF have been shown to be heavier than those born from conventional IVF, which fits in with the findings of this study that un-stimulated endometrium is healthier for the growth of babies. Furthermore, maternal complications such as ovarian hyperstimulation syndrome (OHSS)can be avoided in mild IVF cycles. Conventional IVF is still the common form of IVF practiced in the UK but following this study, it will be increasingly difficult to justify transfer of fresh embryos in cycles with high oestrogen levels.

Two unexplained findings from the study are also worthy of comment. Women who conceived following a period of infertility but who were never treated had a higher risk of unfavourable pregnancy outcomes. However the authors could not confirm whether the women were self-medicating with fertility drugs or were having therapies through specialist clinics which might have influenced the outcomes.

Finally, there is one further important lesson from this study. The Australian team were able to link the data from women having IVF treatment to their pregnancy and delivery database, which allowed the correlation of treatment and outcome to be obtained. In the UK almost 50,000 IVF cycles are carried out each year but no reliable outcome data is obtained because there is no linkage of the IVF database to the UK perinatal database. This must be addressed as a matter of urgency.