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3 February 2014

Event report: Double Take – Twins in genetics and fertility treatment

Progress Educational Trust’s annual conference tackled a number of contentious issues.

The conference took place at London’s Institute of Child Health on 4 December 2013. The morning’s discussions explored what research into twins can tell us, moving into a wider discussion of the ‘nature/nurture’ debate.

A session titled ‘What do we know about twins?’ included presentations by George Attilakos, Consultant in Fetal Medicine and Obstetrics and Lead Clinician for the Maternal-Fetal Assessment Unit at University College Hospital, on ‘Chorionicity and Zygosity: Why Do We Still Get It Wrong?’; Dr Jane Hurst, Lead Clinician and Consultant in Clinical Genetics at Great Ormond Street Hospital, on ‘Why and How Identical Twins Can Be Different and Non-Identical Twins Similar’; and Sir John Burn, Professor of Clinical Genetics at Newcastle University’s Institute of Genetic Medicine, on ‘Twinning Causes Discordant Heart Malformation’. A report on this session is available in BioNews, here.

This was followed by a session titled ‘What can we learn from twins?’, which is reported in BioNews, here.

Presentations by Robert Plomin, Professor of Behavioural Genetics at the Social, Genetic and Developmental Psychiatry Centre; Marcus Pembrey, Emeritus Professor of Paediatric Genetics at University College London’s Institute of Child Health; and Dr Jordana Bell, Senior Lecturer at King’s College London’s Department of Twin Research and Genetic Epidemiology, all addressed the relationship between genes and environment. Plomin’s remarks have been subject to much discussion in the mainstream press, in relation to the ongoing debates about the relative impact of nature versus nurture upon an individual’s IQ.

Later sessions focused on the clinical issues raised by twins, particularly in relation to fertility treatment. In a presentation provocatively titled ‘IVF Twins: Fulfilling Dreams or Turning Them into a Nightmare?’, Dr Yacoub Khalaf, Director and Person Responsible of Guy’s Hospital’s Assisted Conception Unit, painted a bleak picture of the impact of having twins on maternal morbidity, as well as being ‘the single biggest risk to the health and welfare of children born after IVF’. The major issue with twins, he argued, is prematurity, which has complications both in the long and short term; and he insisted, in conclusion, that clinicians ‘must resist temptation to implant multiple embryos inappropriately’. 

Dr Nicky Hudson, Senior Research Fellow and Leader of the Reproduction Research Group at De Montfort University, gave a thought-provoking presentation titled ‘“What I Wanted Was to Have One More Put Back than You Can Here”: Decision-making About Embryo Transfer in Cross-Border Fertility Treatment’. Hudson noted that the literature on patient choices indicates that twins are generally preferred, if pregnancy rates are equal. These preferences are not stable over time, and reflect the wider issues affecting couples seeking fertility treatment.

For example, her study found that couples gave many reasons for their desire to seek treatment abroad, and the main ones related to the cost of treatment in Britain and the shortage of egg and sperm donors. Accessing multiple embryo transfer (MET) was cited as a reason in one case; and indeed, MET is becoming less common in Europe too, as the success of SET techniques increases. However, while the medical risks of multiple embryo transfer tend to be highlighted, couples are also faced with the ‘social and psychological risks’ of ending up with no pregnancy at all, and this weighs on their decision. For most patients, decisions about MET seem to be based more on a calculation of failure v success, rather than a particular desire for twins v singletons.

Jane Fisher, Director of Antenatal Results and Choices, talked about ‘Multiple Dilemmas: The Implications of Prenatal Diagnosis in Twin Pregnancies’. She noted that the risk of chromosomal abnormality is higher in twin pregnancies. The chance of a test giving a false positive result is also higher, and this is driving the interest in non-invasive prenatal testing (NIPT), because invasive testing has a higher miscarriage risk than singletons. Fisher noted that there is a stigma attached to screening for IVF pregnancies, and that the grieving process that can be undergone by women who decide on selective reduction in multiple pregnancies is often not sensitively understood. 

In an explosive debate on Single Embryo Transfer Policy, the lawyer James Lawford Davies gave his account of ‘challenging regulatory overreach’ in the court case between Mohamed Taranissi, Founder and Medical Director of the Assisted Reproduction and Gynaecology Centre (ARGC) and the Reproductive Genetics Institute (RGI), and the with the Human Fertilisation and Embryology Authority (HFEA), the body that regulates clinics providing fertility treatment. 

In November, the High Court ruled that the HFEA’s actions towards two clinics, for which Taranissi was Person Responsible, over a licence condition to impose a maximum multiple birth rate were unlawful. Taranissi challenged the HFEA’s decision to impose the condition, known as T123, on the grounds that the decision on the number of embryos to be transferred to the patient should be a medical one, taking into account the patient’s age, medical history and chances of conceiving.

During the case, Taranissi argued that if his clinics had reached the multiple birth quota midway through the year, they would then be forced to offer all remaining patients only one embryo if they wished to comply with the condition. ‘It is my understanding that many clinics are not able to meet this target, and that it has already had an adverse impact on pregnancy rates’, he said in a statement. ‘Clinics with a higher percentage of patients who are over 40 and who have had several failed IVF attempts would have fallen foul of the HFEA’s ten percent condition even though they are simply providing universally recognised standard treatment by transferring two embryos’.

Speaking to the Progress conference, James Lawford Davies outlined the significance of this case. It is a criminal offence to provide IVF without a licence from the HFEA, and if clinics do not comply with the HFEA’s conditions, their licence can be revoked. The ARGC and the RGI, he explained, decided to exercise their statutory right to make representations. As Mohamed Taranissi emphasised in his presentation to the conference, this was not about challenging the multiple birth policy itself: nobody, he stated, wants to oppose a policy to minimise multiple births, or deny the enhanced risks that are associated with multiple births.

His objection was to the HFEA making compliance a condition for the licences. This this should be a matter for clinical judgement; and furthermore, it is unnecessary, given that the sector is ‘largely compliant’. Lawford Davies argued that the policy came about because the HFEA anticipated that clinics would have difficulties in meeting the 10% target, and therefore needed enforcement. The High Court, however, ruled that that HFEA had no power to impose this condition before the statutory process was completed.

The HFEA subsequently decided to withdraw the condition from all UK fertility clinics’ licences. But Nick Jones, the HFEA’s Director of Compliance, told the Progress conference that this letter did not show a change in attitude – the HFEA remains committed to reducing multiple births. The reduction in the multiple birth rate as a result of IVF represents, he argued, a ‘public health success story’, and stands as a ‘model of turning policy into practice’. Jones argued that the HFEA knew that this policy would ‘rub against’ the ‘personal preferences’ of clinicians and patients, and that the reduction in the multiple birth rate is ‘testament to hard work across the board, but only possible because of the HFEA’.

Rachel Cutting, Chair of the Association of Clinical Embryologists, and Principal Embryologist and Person Responsible at Royal Hallamshire Hospital’s Centre for Reproductive Medicine and Fertility, claimed that the benefits of elective Single Embryo Transfer are accepted worldwide. The UK policy works, she argued, because it is not a blanket policy, but allows clinical input and flexibility – in some cases, Double Embryo Transfer is appropriate. Cutting emphasised the ‘high costs’ of multiple pregnancy to neonatal care, and explained that that the success in eSET has been driven by improvements in technology, which mean that it is less likely to reduce a patient’s chance of pregnancy.

Taranissi argued that the multiple birth rate was already going down, before the enforcement of the HFEA’s policy: a trend that speaks to the significance of technological improvements and clinical judgement over regulatory enforcement. However, the question of multiple births should be detached from that of the number of embryos transferred. In 2011, the most common number of embryos transferred in each cycle was two; and a double embryo transfer is three times more likely to result in singleton birth than in twins. The vast majority of women receiving eSET are aged 37 and under, and on their first cycle of treatment. The problem with the imposition of a 10% target is that it is far easier to meet in clinics that treat women whose fertility problems are less severe. 

Overall, this fascinating conference left delegates with some key questions. If a woman wants to have twins, how should clinicians view the balance between the relatively higher clinical risks of multiple births, and the fact that twins remain a ‘normal’ part of reproduction and the outcome of many twin pregnancies is fine? How far should patient choice be able to influence clinical decisions about the number of embryos to put back? And what are the broader consequences of allowing regulatory target-setting to override clinical decision-making?

Read more reports here:

Progress Educational Trust conference: What can we learn from twins? By Professor John Galloway. BioNews 735

Progress Educational Trust conference: What do we know about twins? By Dr Jess Buxton. BioNews 735

Progress Educational Trust conference: Multiple choice question. By Daniel Malynn. BioNews 736

Progress Educational Trust conference: SET in stone - single embryo transfer policy. By Ruth Saunders. BioNews 737