Table 2.

Occupational factors^a by pregnancy outcome.

	Spontaneous Abortion <20 weeks gestation n=775 (10.4%)		Live Birth n=6707 (89.6%)
Self-reported Occupational Exposuresb
“On average, how many hours per day did you work with the following agents:”
“Anesthetic gases (e.g. nitrous oxide, halothane, enflurane, isoflurane)?”
<1 (reference)	706	90.6	6,133	91.5
1–4	30	3.9	234	3.5
4–8	29	4.3	274	4.1
9+	10	1.2	66	1.0
“Anti-cancer drugs (e.g., Cytoxan, Fluroplex, Adrucil, Etoposide, 5-FU)?”
<1 (reference)	727	92.8	6,453	96.2
1–4	39	5.8	202	3.0
4–8	8	1.3	45	0.7
9+	1	0.1	7	0.1
“Anti-viral drugs (e.g., Gancyclovir) or the interferons?”
<1 (reference)	724	93.1	6,333	94.5
1–4	45	6.2	354	5.2
4–8	6	0.8	16	0.2
9+	0	0.0	4	0.1
“Sterilizing agents (e.g., ethylene oxide, formaldehyde, glutaraldehyde?”
<1 (reference)	699	90.7	6,210	92.7
1–4	68	8.5	435	6.4
4–8	8	0.7	51	0.7
9+	0	0.0	11	0.2
“X-ray radiation?”
<1 (reference)	650	81.5	5,781	86.3
1–4	116	17.1	852	12.6
4–8	8	1.2	61	0.9
9+	1	0.2	13	0.2
Work Scheduleb
“What schedule did you usually work? If most of work hours are between 8 am-4pm, then it is “day”; if 4pm-midnight, then it is “evening”; if midnight-8am, then it is “night.”
Shift
Days only (reference)	536	66.7	4,573	68.6
Nights only	89	12.7	575	8.5
Rotating shifts including nights	54	7.4	433	6.4
Day/Evening rotating; no nights	96	13.2	1,126	16.5
Hours worked (hours/week)
1 – 20	158	24.7	1,707	25.2
21 – 40	397	49.0	3,846	57.4
41+	220	26.2	1,154	17.4

^aPercentages for all variables except maternal age are directly standardized by year of age at current pregnancy

^bTrimester-specific occupational exposures and work schedule were collected by questionnaire.