Male gonadal dose of ionizing radiation delivered during X-ray examinations and monthly probability of pregnancy: a population-based retrospective study

Table 2 Adjusted Hazard Ratios of pregnancy and 95% confidence intervals according to male gonadal dose.

	n	%	HR *	95% CI		p values
Male gonadal dose (mGy)						0.55
No X-ray examination	491	48.0	1.03	0.80	1.31
0.01–0.20	321	31.4	1			p for trend
0.21–2.00	101	9.9	0.86	0.59	1.26	0.27
2.01–5.00	55	5.4	1.32	0.81	2.15
5.01–10.00	24	2.3	1.38	0.68	2.80
> 10.00	31	3.0	1.44	0.73	2.86
Female age ^† (years)						0.15
< 20	21	2.1	0.57	0.28	1.17
20–24	321	31.4	1.00	0.79	1.28	p for trend
25–29	466	45.5	1			0.05
30–34	177	17.3	0.79	0.59	1.07
35–39	34	3.3	0.88	0.45	1.71
≥40	4	0.4	0.19	0.04	1.00
Menstrual cycle regularity						0.09
Regular	708	69.2	1
Irregular	159	15.5	0.69	0.46	1.03
Oral contraception as usual birth control	156	15.3	1.23	0.86	1.78
Menstrual cycle length (days)						0.07
< 21	16	1.6	0.91	0.36	2.29
21–27	255	24.9	1.24	0.90	1.70
28	433	42.4	1
29–35	251	24.6	0.92	0.66	1.27
> 35	68	6.6	0.51	0.27	0.95
Female tobacco consumption ^‡ (cigarettes/day)						0.24
0	639	62.5	1
1–10	244	23.8	0.92	0.71	1.20	p for trend
11–20	129	12.6	0.86	0.61	1.20	0.08
> 20	11	1.1	0.36	0.13	1.02
Female genital and urinary tract diseases ^†,§						0.16
No	939	91.8	1
Yes	84	8.2	0.75	0.50	1.12
Male age ^† (years)						0.42
< 25	162	15.8	0.74	0.51	1.09
25–29	466	45.6	0.94	0.74	1.21	p for trend
30–34	288	28.2	1			0.36
35–39	87	8.5	0.81	0.53	1.24
≥ 40	20	1.9	0.68	0.30	1.54
Male genital and urinary tract diseases ^†,¶						0.80
No	888	86.8	1
Yes	135	13.2	0.95	0.68	1.33

(n = 1023 pregnancies or periods of involuntary infertility lasting one year or more for 657 couples living in Beaumont-Hague and in the Saint-Brieuc area, France).
* Hazard Ratio (HR) of pregnancy adjusted for calendar year at the beginning of the period of unprotected intercourse, area of inclusion and for the variables detailed in the table. A value below 1 indicates a decreased probability of pregnancy compared to the reference category.
^† At the beginning of the period of unprotected intercourse.
^‡ During the period of unprotected intercourse (time-dependent variable). Sample sizes are given for the first month of the period of unprotected intercourse.
^§ Previous history of ovarian or uterine cancer, salpingitis, endometriosis, ovarian cysts or infection, genital tract operation, Chlamydia infection.
^¶ Previous history of cancer, mumps with testes injury, cryptorchidism, inguinal hernia, varicocele, testes torsion, gonococci, epididymitis, cystis, prostates, genital tract operation, Chlamydia infection.

ISSN: 1471-2458