Geographical Differences in Male Infertility between the United States and Canada: Insights from the Andrology Research Consortium

Table 2

Fertility histories and previous infertility treatments of men stratified by Canada and the US.

Covariate	Full sample ()	Canada ()	USA ()	value
Referral				<0.001
Self-referred	154 (3%)	41 (1%)	113 (17%)
Primary care physician/family doctor	781 (16%)	674 (16%)	107 (16%)
Gynecologist/reproductive endocrinologist/women’s fertility specialist	3163 (66%)	2812 (68%)	351 (54%)
Other	713 (15%)	628 (15%)	85 (13%)
Missing	1651	1623	28
Infertility duration, years				0.0066
Mean (SD)	3.7 (4.4)	3.6 (4)	4.5 (7.2)
Median (range)	2 (0-67)	2 (0-45)	2 (0-67)
Missing	837	758	79
Vasectomy				<0.001
No	6091 (94%)	5469 (95%)	622 (91%)
Yes	371 (6%)	309 (5%)	62 (9%)
Semen analysis				0.0019
No	172 (17%)	41 (12%)	131 (20%)
Yes	815 (83%)	294 (88%)	521 (80%)
Missing	5475	5443	32
Semen analysis results				0.0021
No	105 (13%)	47 (17%)	58 (11%)
Unknown	84 (11%)	40 (14%)	44 (9%)
Yes	602 (76%)	193 (69%)	409 (80%)
Missing	5671	5498	173
Intrauterine insemination				<0.001
No	5665 (88%)	5028 (87%)	637 (93%)
Yes	797 (12%)	750 (13%)	47 (7%)
Intrauterine insemination cycles				0.32
Mean (SD)	1.6 (1.0)	1.6 (1.0)	1.9 (1.3)
Median (range)	1 (1-8)	1 (1-8)	1 (1-5)
In vitro fertilization				0.014
No	6034 (93%)	5411 (94%)	623 (91%)
Yes	428 (7%)	367 (6%)	61 (9%)
In vitro fertilization cycles				0.40
Mean (SD)	1.4 (0.8)	1.4 (0.9)	1.3 (0.6)
Median (range)	1 (1-8)	1 (1-8)	1 (1-3)
Number of pregnancies				<0.001
0	2339 (85%)	2132 (88%)	207 (66%)
1+	405 (15%)	296 (12%)	109 (34%)
Missing	3718	3350	368
Number of babies				<0.001
0	2441 (91%)	2262 (93%)	179 (71%)
1+	237 (9%)	164 (7%)	73 (29%)
Missing	3784	3352	432
Number of pregnancy losses				1
0	269 (69%)	122 (69%)	147 (69%)
1+	122 (31%)	55 (31%)	67 (31%)
Missing	6071	5601	470

Bold values represent statistically significant -values.