O-297 Does advanced paternal age influence live birth rate independent of woman’s age: analysis of 18, 825 fresh IVF/ICSI cycles from a national (HFEA) database

Abstract Study question Does advanced paternal age (APA) impact live birth rates (LBRs) in IVF/ICSI treatment independent of female partner’s age? Summary answer LBRs decline with paternal age ≥40 years, but not when female partner is < 35 or ≥ 40 years. What is known already APA, particularly over 40 years, has been shown to be associated with declining sperm parameters, impaired embryo development, aneuploidy, compromised pregnancy outcomes and mental health abnormalities in the offspring in IVF/ICSI cycles. However, no significant effect of APA on pregnancy outcomes has been noted in donor oocyte cycles, indicating possible positive effect of female age counteracting negative male age-related IVF/ICSI outcomes. Data on whether female and male age influence each other, or are independently related to LBR, are limited and inconclusive. Study design, size, duration Retrospective analysis of 18, 825 autologous IVF or ICSI with fresh single embryo transfer (SET) cycles from the UK’s national anonymised registry, published online by the Human Fertilisation and Embryology Authority (HFEA). Study period: 2 years starting from 1st January 2017 to 31st December 2018. Participants/materials, setting, methods Couples underwent IVF/ ICSI with fresh SET due to unexplained or tubal infertility. Cycles with male factor, donor sperm and preimplantation genetic testing were excluded. Female age was grouped to < 35 years, 35-39 years and 40-44 years; male age to < 35 years (control group), 35-39 years, 40-44 years, 45-50 years, 51-55 years and >55 years. Chi-square to compare binominal data; multiple logistic regression to find correlation of male and female age on LBR adjusting confounders. Main results and the role of chance Overall, LBR per SET declined from 39.1% in men <35 years (control group) to 25.9% (p < 0.0001), 23.0% (p < 0.0001), 22.9% (p < 0.0001) and 25.4% (p = 0.002) in 40-44, 45-50, 51-55 and >55 years, respectively. However, in the subgroups of women <35 years, the LBRs were no different whether men were of < 35 (41.3%), 40-45 (40.8%) or > 55 (41.7%) years. Similar trend was observed in women aged 40-44 years: LBRs were 12.3%, 11.9%, and 17.4% in men aged <35, 40-44, and >55 year, respectively. Only in women aged 35-40 years, LBRs dropped from 32.8% in men aged <35 years down to 27.9% (p = 0.004), 28.1% (p = 0.04), 28.7% (p = 0.33) and 25% (p = 0.22) in 40-44, 45-50, 51-55 and >55 years, respectively. The findings remained the same with ICSI only cycles. Individually, male age, female age, treatment-type (IVF or ICSI) and day of transfer were significantly correlated with LBR. Overall, after adjusting for confounders, both male (p = 0.01) and female’s age (p < 0.0001) remained independently related to LBRs.; male age did not correlate with LBRs in women aged <35 years or 40-44 years. Limitations, reasons for caution Information on ovarian reserve and treatment protocols were not available. However, this may have little impact, given large population studied. Exclusion of male infertility might have reduced the ‘effect-size’ but was important to eliminate non-age-related male factors, in order to assess only men’s age on the pregnancy outcome. Wider implications of the findings Oocytes in women <35 appear to reduce the negative impact of older sperm on LBR, but not in women 35-39 years of age. This is useful information when counselling couples and in fertility education setting. Further research is needed to clarity the mechanism underlying our findings. Trial registration number Does advanced paternal age influence live birth rate independent of woman’s age: analysis of 18, 825 fresh IVF/ICSI cycles from a national (HFEA) database