Non-invasive embryo testing is becoming a reality – but we’re not there yet

Until now genetic screening of embryos for chromosomal abnormalities has required taking a few cells from the embryo.  The disadvantages of this are a small risk of damage to the embryo and the cost involved in the procedure

The new test looks at the fluid that the embryo has been growing in.  This contains traces of DNA from the embryo.

How non-invasive embryo testing is developing globally

US company PerkinElmer showcased their new niPGT-A testing kit at a scientific congress in Philadelphia this month. They’ve collected data from 15 laboratories worldwide comparing biopsy result with culture medium results and have found more than 90% correlation between the two.  Not perfect but a very good start.

In Australia Monash IVF began offering non-invasive testing in all it’s clinics in May and they report 95% concordance between biopsy and culture medium results.  The test is available for $495 (£263) per embryo.

Where is the DNA being released from?

The procedure remains controversial  – genetic consultant Dr Antonio Capalbo presenting at an ESHRE meeting in September stated that more questions need answering before the test is ready for clinical use.

A concern is that we don’t yet know exactly where the DNA in the culture medium is coming from.  It’s not certain that it’s coming from the inner cell mass of the embryo, or may come from cells surrounding the embryo. Contamination with other DNA could affect results.

In the UK a case study at IVF clinic CRGH combined both invasive and non-invasive testing on two embryos resulting in ongoing pregnancy.  The study states non-invasive testing to be an addition to diagnosis rather than a replacement for embryo biopsy.  At least until we know more.

Advantages of non-invasive embryo screening

  • increased accessibility

  • lower cost

  • no need to wait until the embryo has hatched, so information is more easily obtained about each embryo

  • it is possible that the fluid may show a more complete picture of the embryo’s genetic health than taking a few cells with biopsy – research is ongoing with this

Disadvantages of non-invasive embryo screening

  • can only be used on embryos which have been fertilised by ICSI - this is to avoid picking up the sperm’s DNA instead of the embryo’s DNA

  • embryos need to be cultured until day 6 - getting sufficient DNA into the culture medium takes time

  • a small percentage of embryos may not release enough DNA into the culture medium

Medical Cannabis at the RSM

Really interesting evening at the Royal Society of Medicine last night looking at medical cannabis.  CBD products are commercially available everywhere now, it’s become big business and many claims are made.  Prescribing cannabis has been legal in the UK for a year. The effect is to create a sense of optimism about what the non-intoxicating  elements of cannabis can do for our health.

So… I went keen to hear the evidence of how CBD might help patients with inflammatory conditions, chronic pain and more.

Speakers included… consultant gastroenterologist Dr Peter Irving talking about Inflammatory Bowel Disease, psychopharmacology researcher Dr Amir Englund discussing psychiatric disorders, Professor of neurology Praveen Anand looking at pain, and consultant urologist Dr Zeid Mohamedali describing his experience and research prescribing medical cannabis in Canada.

My impressions?

We need a lot more high quality research.  The word ‘signalling’ was used a lot in relation to research – the evidence isn’t there yet but there are signs of promise.

Cannabis is a very complex herb – you are dealing with not one but two main active substances and these need to be carefully balanced.

The importance of ‘personalised medicine’ was discussed – each case needs to be assessed individually – people respond to cannabis differently.

Wondering if medical cannabis can help you? - Key take aways from the event

  • Research for most conditions is somewhat underwhelming – but there may be many reasons for this –  differences in cannabis strains, how it’s grown and how it’s taken all significantly influence it’s effect

  • Case histories from doctors specialising in its use were more convincing than the research

  • Like most herbs cannabis works best when the whole plant is used – using CBD on it’s own may not give the best therapeutic effect.  THC can enhance the effect of CBD.

  • Dosage needs to be titrated carefully

  • It’s important to start slowly and build up tolerance gradually

  • You need a specialist to help you

  • NICE guidelines state that prescribing can only be done by a specialist for your condition, not by your GP

  • If you don’t have a specialist may be able to help