Table 1.
Estimates and P values of the linear mixed model (semen parameters as outcome) and the generalized linear mixed effects (GLME) model (pregnancy as outcome)
| Semen parameters | Linear mixed model | Unadjusted GLME model | Adjusted GLME model for male age | |||||
|---|---|---|---|---|---|---|---|---|
| Pregnant group, 254 cycles, 228 couples | Non-pregnant group, 1475 cycles, 575 couples | Total group, 1729 cycles, 662 couples | P value pregnancy | OR semen parameter | P value | OR semen parameter | P value | |
| Abstinence (days) | 3.6 (0.09) | 3.6 (0.05) | 3.6 (0.04) | 0.599 | 0.994 [0.893,1.105] | 0.907 | 1.002 [0.900,1.115] | 0.973 |
| Volume (ml)* | 3.8 (0.10) | 3.7 (0.07) | 3.8 (0.07) | 0.446 | 1.044 [0.978,1.114] | 0.197 | 1.042 [0.977,1.112] | 0.210 |
| Sperm concentration (M/ml)* | 42.2 (2.1) | 42.3 (1.5) | 42.2 (1.4) | 0.991 | 1.000 [0.997,1.003] | 0.976 | 1.000 [0.997,1.003] | 0.931 |
| Total sperm count (M/ejaculate)* | 163.8 (8.2) | 158.0 (5.2) | 159.0 (5.0) | 0.458 | 1.000 [1.000,1.001] | 0.514 | 1.000 [1.000,1.001] | 0.516 |
| Progressive sperm motility (%) | 48.6 (0.71) | 47.7 (0.45) | 47.9 (0.43) | 0.185 | 1.005 [0.993,1.018] | 0.406 | 1.004 [0.992,1.017] | 0.521 |
| Total sperm motility (%) | 55.1 (0.78) | 54.6 (0.46) | 54.7 (0.43) | 0.538 | 1.003 [0.992,1.015] | 0.587 | 1.002 [0.991,1.014] | 0.738 |
| Total motile sperm count (M/ejaculate)* | 87.2 (4.9) | 83.1 (3.1) | 83.9 (3.0) | 0.371 | 1.000 [0.999,1.001] | 0.542 | 1.000 [0.999,1.001] | 0.595 |
| Sperm morphology (%) | 6.5 (0.21) | 6.6 (0.16) | 6.6 (0.16) | 0.371 | 0.977 [0.941,1.014] | 0.225 | 0.980 [0.944,1.017] | 0.289 |
| Inseminating progressive motile count (M)* | 5.7 (0.29) | 5.6 (0.18) | 5.6 (0.17) | 0.920 | 0.986 [0.960,1.014] | 0.323 | 0.984 [0.957,1.012] | 0.257 |
| Time interval between semen production and start analysis* | 28.9 (0.49) | 30.1 (0.25) | 29.9 (0.23) | 0.037 | 0.985 [0.969,1.002] | 0.090 | 0.987 [0.970,1.003] | 0.119 |
| Time between semen production and IUI* | 102.0 (1.55) | 103.9 (0.74) | 103.6 (0.68) | 0.250 | 0.996 [0.990,1.002] | 0.212 | 0.997 [0.991,1.003] | 0.275 |
| Female age (years) | 31.9 (0.18) | 31.9 (0.17) | 31.9 (0.17) | 0.344 | 0.961 [0.927,0.997] | 0.034 | ||
| Male age (years) | 34.5 (0.23) | 34.5 (0.23) | 34.5 (0.23) | 0.341 | 0.958 [0.930,0.987] | 0.005 | ||
Values are estimated means (SE) or OR (odds ratio [95% CI])
*Means and SE back transformed after logarithmic transformation in the linear mixed model