Table I. Baseline characteristics
n=602 Mean or n 5th – 95th percentile or %
Female age , in years 33.6 27 – 38
Duration of subfertility, in years 2.6 1.28 – 5.2 Primary subfertility vs. secondary
subfertility
458 76%
Progressively motile semen, % 44 14 – 72 Referral by secondary care vs.
referral by general practitioner
72 14%
1 2 3
4 5
Table II. Estimated natural conception rates leading to ongoing pregnancy for different female age and duration of subfertility
Female age in years
Duration of subfertility in
years
Estimated natural conception rate over 12
months (95% CI)
18 1 35% (19-49)
18 2 33% (18-45)
18 3 31% (17-42)
23 1 33% (21-43)
23 2 30% (20-39)
23 3 28% (19-37)
28 1 30% (22-38)
28 2 28% (21-34)
28 3 26% (19-32)
33 1 28% (21-34)
33 2 26% (20-31)
33 3 24% (19-28)
38 1 25% (19-32)
38 2 24% (18-29)
38 3 22% (16-27)
6 7 8 9
Figure 1. Estimated cumulative natural conception rate leading to ongoing pregnancy after 12 months of sexual intercourse derived from the Cox model. The leap in the model was due to pregnancies in the second month of follow up that could not be traced to a specific date following sonography, which were set at the same follow up.
10 11 12 13
14
