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Publication - Professor Kate Tilling

    Live-birth rate associated with repeat in vitro fertilization treatment cycles

    Citation

    Smith, ADAC, Tilling, KM, Nelson, SM & Lawlor, DA, 2015, ‘Live-birth rate associated with repeat in vitro fertilization treatment cycles’. JAMA - Journal of the American Medical Association, vol 314., pp. 2654-2662

    Abstract

    Importance 
    The likelihood of achieving a live birth with repeat in vitro
    fertilization (IVF) is unclear, yet treatment is commonly limited to 3
    or 4 embryo transfers.

    Objective 
    To determine the live-birth rate per initiated ovarian stimulation IVF cycle and with repeated cycles.

    Design, Setting, and Participants 
    Prospective study of 156 947 UK women who received 257 398 IVF
    ovarian stimulation cycles between 2003 and 2010 and were followed up
    until June 2012.

    Exposures 
    In vitro fertilization, with a cycle defined as an episode of
    ovarian stimulation and all subsequent separate fresh and frozen embryo
    transfers.

    Main Outcomes and Measures 
    Live-birth rate per IVF cycle and the cumulative live-birth
    rates across all cycles in all women and by age and treatment type.
    Optimal, prognosis-adjusted, and conservative cumulative live-birth
    rates were estimated, reflecting 0%, 30%, and 100%, respectively, of
    women who discontinued due to poor prognosis and having a live-birth
    rate of 0 had they continued.

    Results 
    Among the 156 947 women, the median age at start of treatment
    was 35 years (interquartile range, 32-38; range, 18-55), and the median
    duration of infertility for all 257 398 cycles was 4 years
    (interquartile range, 2-6; range, <1-29). In all women, the
    live-birth rate for the first cycle was 29.5% (95% CI, 29.3%-29.7%).
    This remained above 20% up to and including the fourth cycle. The
    cumulative prognosis-adjusted live-birth rate across all cycles
    continued to increase up to the ninth cycle, with 65.3% (95% CI,
    64.8%-65.8%) of women achieving a live birth by the sixth cycle. In
    women younger than 40 years using their own oocytes, the live-birth rate
    for the first cycle was 32.3% (95% CI, 32.0%-32.5%) and remained above
    20% up to and including the fourth cycle. Six cycles achieved a
    cumulative prognosis-adjusted live-birth rate of 68.4% (95% CI,
    67.8%-68.9%). For women aged 40 to 42 years, the live-birth rate for the
    first cycle was 12.3% (95% CI, 11.8%-12.8%), with 6 cycles achieving a
    cumulative prognosis-adjusted live-birth rate of 31.5% (95% CI,
    29.7%-33.3%). For women older than 42 years, all rates within each cycle
    were less than 4%. No age differential was observed among women using
    donor oocytes. Rates were lower for women with untreated male
    partner–related infertility compared with those with any other cause,
    but treatment with either intracytoplasmic sperm injection or sperm
    donation removed this difference.

    Conclusions and Relevance 
    Among women in the United Kingdom undergoing IVF, the
    cumulative prognosis-adjusted live-birth rate after 6 cycles was 65.3%,
    with variations by age and treatment type. These findings support the
    efficacy of extending the number of IVF cycles beyond 3 or 4.


    Full details in the University publications repository