Table 1.

Cross-tabulation of Maternal Smoking Categorization and Individual Smoking Trajectory Class

		Nonsmoker	Quit before pregnancy	Not SDP, then relapse	Not SDP, relapse, then quit	SDP, quit after pregnancy	SDP, continue after pregnancy	Total
Early start	N	202	33	83	48	42	225	633
	%	8.1	10.9	16.1	13.3	14.3	21.2	12.6
Early experiment	N	48	9	17	9	8	36	127
	%	1.9	3.0	3.3	2.5	2.7	3.4	2.5
Late start	N	385	37	133	95	70	238	958
	%	15.5	12.2	25.7	26.2	23.8	22.4	19.1
Never smoke	N	1,854	224	284	210	174	563	3,309
	%	74.5	73.9	54.9	58.0	59.2	53.0	65.8
Total	N	2,489	303	517	362	294	1,062	5,027
	%	100	100	100	100	100	100	100

Note. SDP = smoke during pregnancy.