13. Results Characteristic Group A Older men ( n = 227) Group B Younger men ( n = 227) P -value Paternal age (years) 53.9 5.0 38.4 5.8 <0.0001 Maternal age (years) 33.2 4.9 32.7 4.8 NS Duration of infertility (years) 7.8 6.2 7.8 5.4 NS Aetiology n (%) Male factor 119 (52.4) 88 (38.8) 0.0047 Unexplained infertility 41 (18.1) 47 (20.7) NS Tubal factor 28 (12.3) 46 (20.3) 0.031 Mixed 25 (11.0) 32 (14.1) NS Ovulatory factor 14 (6.2) 14 (6.2) NS
14. Semen Quality Characteristic Group A Older men ( n = 227) Group B Younger men ( n = 227) P -value Sperm concentration ( 10 6 /ml) 39.0 26.3 46.0 32.6 0.05 Sperm motility (%) 37.4 20.4 46.4 15.5 <0.0001 Sperm abnormal forms (%) 74.0 11.5 81.3 10.6 0.019
15.
16. Outcome of intracytoplasmic sperm injection cycles in Group A (male age ≥50 years) and Group B (male age <50 years). a,bP<0.0001. There were no other statistically significant differences. Outcome Group A ( n = 227) Group B ( n = 227) No. of oocytes 10.8 6.8 10.5 6.2 No. oocytes with polar body 7.9 5.3 8.1 4.9 No. 2PN embryos 5.1 3.8 5.4 3.5 Fertilization rate (%) 64.9 25.4 a 66.7 25.6 b Grade of embryo 0.6 1.1 0.7 1.0 No. of cryopreserved embryos 1.9 3.3 1.7 2.8 No. of embryos transferred 2.7 1.1 2.8 1.0 Pregnancy rate (%) 37.9 36.6
17. Subgroup analysis There were no statistically significant differences between the two groups Parameter Group A1 ( n = 198) Group A2 ( n = 29) Paternal age (years) 52.5 2.7 64.1 6.2 Maternal age (years) 33.2 4.9 33.5 4.8 Duration of infertility (years) 8.0 6.3 6.7 5.7 No. of oocytes 10.9 6.8 9.7 6.3 No. of oocytes with polar body 8.0 5.3 7.1 5.1 No. 2PN embryos 5.2 3.9 4.6 3.5 No. of cryopreserved embryos 1.9 3.3 1.7 2.7 No. of embryos transferred 2.7 1.1 2.5 1.2 Pregnancy rate (%) 38.2 35.2
18. Multiple logistic regression analysis for factors affecting pregnancy rate Factor P -value Male age 0.6507 Female age 0.6356 Duration of infertility 0.8428 No. of oocytes 0.0079 No. oocytes with polar body 0.0056 No. 2PN embryos 0.8628 No. of cryopreserved embryos 0.6374 No. of embryos transferred 0.9361
There was a significant difference in sperm count ( P = 0.05) and significantly increased motility of spermatozoa in group B as compared with group A ( P < 0.0001
Subgroup analyses comparing paternal age from 50 to 59 years (group A1) with paternal age 60 years and above (group A2) showed no significant differences between the studied groups with regard to clinical pregnancy or fertilization rates (OR = 1.00, 95% CI = 0.74 1.37 and OR = 1.11, 95% CI = 0.49 2.54 respectively
regression analyses confirmed the lack of a paternal effect on clinical pregnancy rate. The results of simple linear ( P = 0.92) and multiple logistic regression ( P = 0.65) demonstrated that male partner age is only weakly correlated with clinical pregnancy rate. Other factors related to the female partner, such as number of retrieved oocytes ( P = 0.0079) and number of fertilized oocytes ( P = 0.0056), were much more strongly related to treatment outcome. Simple linear regression showed a correlation coefficient ( r ) = 0.00465 ( r 2 = 0.000022), 95% CI for r (Fisher’s Z transformed) = 0.087519 0.09674, two-sided P = 0.9214.