Probability of live birth after IVF/ICSI treatments in female early onset cancer survivors: a Finnish population-based registry study

STUDY QUESTION Does the probability of a live birth after fresh IVF/ICSI cycles with autologous oocytes differ in early onset female cancer survivors compared to their siblings? SUMMARY ANSWER The probability of a live birth was similar in female cancer survivors and siblings after four fresh IVF/ICSI cycles. WHAT IS KNOWN ALREADY Fertility preservation strategies are rapidly being developed to help female cancer patients who wish to have children later. However, there are only a few studies available on fertility treatments and following live births in female cancer survivors before fertility preservation strategies became available. In one of them, the probability of a live birth was reduced after assisted reproductive technology with autologous oocytes in cancer survivors compared to siblings. STUDY DESIGN, SIZE, DURATION In this retrospective, register-based study, data from Finnish registers on cancer, birth and prescribed medications were merged to identify 8944 female cancer survivors (diagnosed with cancer between 1953 and 2012 at the age of 0–40 years) and 9848 female siblings of survivors eligible for IVF/ICSI treatments between January 1993 and December 2012. PARTICIPANTS/MATERIALS, SETTING, METHODS Fresh IVF/ICSI cycles and following live birth rates (LBRs) within 22–48 weeks in cancer survivors and siblings at the age of 20–41 years were identified. A binomial regression model with log-link function was used to calculate risk ratio (RR) for live births after fresh IVF/ICSI cycles in survivors compared to siblings, adjusting for attained age and calendar time. A Poisson regression model was used to estimate incidence rate ratios (IRRs) for an IVF/ICSI treatment, as well as overall live births, including both pregnancies after fertility treatments and spontaneous pregnancies, in survivors compared to siblings. MAIN RESULTS AND THE ROLE OF CHANCE We observed an overall decreased LBR, irrespective of IVF/ICSI treatments, in cancer survivors compared to siblings (IRR 0.68, 95% CI 0.64–0.71). All in all, 179 (2.0%) survivors and 230 (2.3%) siblings were prescribed fertility drugs for IVF/ICSI treatments (IRR 0.72, 95% CI 0.62–0.84). For the first fresh IVF/ICSI cycle, the LBR was 17.2% among survivors and 15.7% among siblings (RR 1.13, 95% CI 0.72–1.87). The mean LBR after four fresh IVF/ICSI cycles was not statistically different in survivors compared to siblings. LIMITATIONS, REASONS FOR CAUTION In this study, only IVF/ICSI treatments with autologous oocytes were included. The probability of a live birth after a frozen embryo transfer or oocyte donation could not be evaluated in this study. Information on miscarriages, extrauterine pregnancies or termination of pregnancies was not available. WIDER IMPLICATIONS OF THE FINDINGS For those early onset cancer survivors, who received IVF/ICSI treatments, the probability of live birth was not different from siblings who received IVF/ICSI treatments. However, an overall decreased LBR, irrespective of IVF/ICSI treatments, was observed in cancer survivors compared to siblings, indicating that cancer survivors receiving IVF/ICSI treatments in our study consisted of a selected group with at least a moderate ovarian reserve. STUDY FUNDING/COMPETING INTEREST(S) This study was supported by a grant from the Cancer Foundation (Finland) (grant number 130079) and by a grant from LähiTapiola. The authors have no potential conflicts of interest. TRIAL REGISTRATION NUMBER N/A.