Table 4.

Rate ratios of birth outcomes (reported at Survey 4) by LFES quintile (at Survey 3) for the young cohort of women in the Australian Longitudinal Study on Women's Health (n 6391)

	Predictor:	n			Unadjusted		Confounders†	Adjusted
Pregnancy outcome	LFES quintile*	0	1	>1	Rate ratio	95 % CI	remaining in model	Rate ratio	95 % CI
Live term birth	1	719	295	882	1·00	Ref.		–	–
	2	803	349	910	0·98	0·92, 1·04		–	–
	3	628	329	903	1·05	0·99, 1·12		–	–
	4	524	288	783	1·08	1·02, 1·15‡		–	–
	5	517	262	1054	1·26	1·19, 1·33‡		–	–
							Smoking	1·44	1·41, 1·48‡
							Maternal age	1·02	1·01, 1·04‡
							Parity	0·93	0·93, 0·94‡
Preterm birth (live, ≤36 weeks)	1	1258	57	7	1·00	Ref.		–	–
	2	1414	67	6	0·91	0·72, 1·16		–	–
	3	1244	53	11	1·23	0·96, 1·57		–	–
	4	1041	46	14	1·26	0·99, 1·62		–	–
	5	1093	66	14	1·44	1·15, 1·80‡		–	–
							Smoking	1·06	1·01, 1·11‡
							Maternal age	1·02	0·99, 1·04
							Parity	1·81	1·74, 1·88‡
							Alcohol	1·07	0·99, 1·15
Stillbirth	1	1313	8	1	1·00	Ref.		–	–
	2	1477	10	0	0·60	0·33, 1·06		–	–
	3	1293	12	1	1·09	0·65, 1·82		–	–
	4	1095	5	0	0·54	0·28, 1·03		–	–
	5	1153	17	1	1·94	1·22, 3·08‡		–	–
							Smoking	0·90	0·79, 1·03
							Parity	2·17	1·99, 2·37‡
Miscarriage	1	1125	145	51	1·00	Ref.		1·00	Ref.
	2	1280	148	58	0·87	0·75, 1·02		0·94	0·80, 1·11
	3	1102	157	46	0·98	0·84, 1·15		0·99	0·84, 1·16
	4	898	151	48	1·06	0·90, 1·24		1·06	0·89, 1·26
	5	941	170	61	1·34	1·16, 1·55‡		1·19	1·02, 1·38‡
							Smoking	1·06	1·03, 1·10‡
							Maternal age	0·99	0·97, 1·00
							Parity	1·33	1·27, 1·39‡
							BMI	1·01	1·00, 1·02‡

LFES, Listeria Food Exposure Score; Ref., referent category.

*LFES quintile 1 = lowest; quintile 5 = highest.

†Smoking, maternal age, parity, alcohol and BMI were included as potential confounders in all stepwise generalized linear models (backward selection). Only those left in the model at P < 0·2 are shown.

‡Statistically significant predictors at P < 0·05.