ICSI is a more invasive option than conventional in-vitro fertilisation (IVF), which can be successful even when semen characteristics are poor. Previous reports of higher fertilisation rates after ICSI suggest that this technique may be better than the conventional method for all couples seeking IVF. Siladitya Bhattacharya and colleagues from Aberdeen University, UK, did a multicentre randomised controlled trial comparing outcome after ICSI or traditional IVF in couples with non-male-factor infertility.
415 couples at four UK centres were randomly assigned IVF or ICSI. The primary outcome was the implantation rate (number of gestation sacs per embryo replaced expressed as a percentage); secondary outcomes were pregnancy and fertilisation rates associated with each treatment. The implantation rate was higher in the conventional IVF group (30%) than in the ICSI group (22%). The pregnancy rate per cycle was also higher after conventional IVF (33% compared with 26%). The average laboratory time was substantially shorter with conventional IVF than with ICSI (23 minutes compared with 74 minutes). The investigators conclude that their results support the current practice of reserving ICSI only for severe male fertility problems.
In an accompanying Commentary (p 2068) Sergio Oehninger from Eastern Virginia Medical School, USA, cautions that the study did not address the impact of the future use of cryopreserved embryos derived from the ICSI and IVF cycles. He comments that this issue needs to be clarified, since the "total reproductive potential" probably represents the best estimate of the overall efficacy of assisted reproductive technique procedures. Nevertheless, he endorses the current practice of indicating ICSI only for male-factor infertility.
NO INCREASED RISK OF NEURODEVELOPMENTAL DELAY FOR CHILDREN CONCEIVED BY ICSI (pp 2068, 2080)
In a second study published in this week's issue of THE LANCET, Alastair Sutcliffe and colleagues from University College London, UK, report the findings of a case-control study which investigated previously reported concerns that children born after IVF by ICSI could be at an increased risk of neurodevelopmental delay. The investigators studied 208 singleton children conceived by ICSI and a control group of 221 normally conceived singleton children. Children were recruited from 22 fertility centres and local nurseries throughout the UK. Controls were selected to match cases as closely as possible for social class, maternal educational attainment, region, sex, and race. The primary outcome measure was neurodevelopmental scoring; secondary measures were perinatal outcomes, postnatal health, and congenital abnormalities.
90% follow-up was achieved for the ICSI group at an average age of 17 months. No difference between the study children and controls was found in neurodevelopmental scores or any subscales on the Griffiths' scales of mental development. Perinatal outcome was similar apart from a higher rate of caesarean section (35% compared with 24%), and a lower average birthweight (3163 g compared with 3341 g) in the ICSI group. Rates of major congenital abnormality were also similar overall (4.8% ICSI compared with 4.5% control).
In his Commentary (p 2068), Sergio Oehninger states: "This new evidence is reassuring in that the majority of children conceived after ICSI were healthy and developmentally normal. However, larger studies with longer follow-up periods, and stratified according to the various spermatozoal defects, are desirable."
Contact: Dr Siladitya Bhattacharya, Department of Obstetrics and Gynaecology, University of Aberdeen, Foresterhill, Aberdeen AB25 2ZD, UK; T) + 44 (0)1224 552457; F) +44 (0)1224 684880; E) s.bhattacharya@abdn.ac.uk
Dr Alastair G Sutcliffe, Royal Free and College Medical School, University College London, Department of Community Child Health, Royal Free Campus, Rowland Hill Street, London NW3 2PF, UK; T) +44 (0)20 7830 2440; F) +44 (0)20 7830 2049; E) icsi@rfhsm.ac.uk
Dr Sergio Oehninger, Department Obstetrics & Gynaecology, The Jones Institute for Reproductive Medicine, Eastern Virginia Medical School, Norfolk, Virginia 23507-1012, USA; E) oehninsc@evms.edu
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The Lancet