Li Z, et al. - Researchers sought to assess the cumulative live birth rate following ICSI cycles compared with IVF cycles for couples with non-male factor infertility. Outcomes suggest that in these couples, ICSI resulted in a similar cumulative live birth rate compared with IVF.

Methods

• Researchers retrospectively evaluated a population-based cohort of 14,693 women, who had their first ever stimulated cycle with fertilization performed for at least one oocyte by either IVF or ICSI between July 2009 and June 2014 in Victoria, Australia.
• They recorded the pregnancy and birth outcomes following IVF or ICSI or the first oocyte retrieval (fresh stimulated cycle and associated thaw cycles) until 30 June 2016, or until a live birth was achieved, or until all embryos from the first oocyte retrieval had been used.
• They obtained data on demographic, treatment characteristics and resulting outcome from the Victorian Assisted Reproductive Treatment Authority.
• From all fertility clinics in Victoria, they collected data items in the VARTA dataset.
• They grouped women by whether they had undergone IVF or ICSI.
• The cumulative live birth rate, which was defined as live deliveries (at least one live birth) per woman after the first oocyte retrieval was assessed as the primary outcome.
• To evaluate the cumulative live birth rate following IVF and ICSI, they used a discrete-time survival model.
• They made adjustment for year of treatment in which fertilization occurred, the woman’s and male partner’s age at first stimulated cycle, parity and the number of oocytes retrieved in the first stimulated cycle.

Results

• Researchers observed 7980 and 13,092 embryo transfers in a total of 4993 women undergoing IVF and 8470 women undergoing ICSI, respectively; these resulted in 1848 and 3046 live deliveries, respectively.
• During the study period, nearly one-fifth of the women (19.0% of the IVF group vs 17.9% of the ICSI group) underwent three or more cycles.
• The median time from oocyte retrieval to live delivery of 8.9 months was observed, for couples who achieved a live delivery, in both IVF (range: 4.2–66.5) and ICSI group (range: 4.5–71.3) (P=0.474).
• In the IVF, a higher fertilization rate per oocyte retrieval was noted compared to that observed in the ICSI group (59.8 vs 56.2%, P < 0.001).
• They observed an overall cumulative live birth rate of 37.0% for IVF and 36.0% for ICSI.
• Women undergoing ICSI and women undergoing IVF were not significantly different regarding the overall likelihood of a live birth (adjusted hazard ratio (AHR): 0.99, 95% CI: 0.92–1.06).
• Non-male factor infertility (female factor only or unexplained infertility) was reported for 64.0% in the IVF group and 36.8% in the ICSI group among couples with a known cause of infertility (P < 0.001).
• ICSI led to a similar cumulative live birth rate compared with IVF among couples with non-male factor infertility (AHR: 0.96, 95% CI: 0.85–1.10).