Table 1.

Characteristics of the Study Population

	CLP isolated n = 494		Not isolated n = 42		CPO isolated n = 321		Not isolated n = 105
	n	%	n	%	n	%	n	%
Maternal age at birth of case
<20	15	3.0	0	0.0	10	3.1	4	3.8
20–29	192	38.9	14	33.3	142	44.2	37	35.2
30–39	251	50.8	22	52.4	145	45.2	63	60.0
≥40	18	3.6	5	11.9	13	4.1	1	0.9
Unknown	18	3.6	1	2.4	11	3.4	0	0.0
Year of birth of case*
1931–1979	54	10.9	2	4.8	8	2.5	1	0.9
1980–1989	139	28.1	12	28.6	73	22.7	9	8.6
1990–1999	217	43.9	13	31.0	146	45.5	57	54.3
2000–2004	83	16.8	15	35.7	94	29.3	38	36.2
Unknown	1	0.2	0	0.0	0	0.0	0	0.0
Maternal smoking
Yes	173	35.0	16	38.1	133	41.4	45	42.9
No	248	50.2	21	50.0	166	51.7	54	51.4
Unknown	73	14.8	5	11.9	22	6.9	6	5.7
Alcohol use during pregnancy
Yes	251	50.8	25	59.5	192	59.8	60	57.1
No	168	34.0	12	28.6	107	33.3	39	37.1
Unknown	75	15.2	5	11.9	22	6.9	6	5.7
Live births
1	73	14.8	7	16.7	59	18.4	24	22.9
2	124	25.1	14	33.3	81	25.2	26	24.8
3	121	24.5	11	26.2	87	27.1	30	28.6
4	87	17.6	8	19.1	51	15.9	13	12.4
5 or more	81	16.4	2	4.8	38	11.8	12	11.4
Unknown	8	1.6	0	0.0	5	1.6	0	0.9
Stillbirths
0	460	93.1	41	97.6	310	96.6	103	98.1
1 or more	20	4.1	1	2.4	4	1.3	2	1.9
Unknown	14	2.8	0	0.0	7	2.2	0	0.0
Miscarriages
0	328	66.4	26	61.9	225	70.1	69	65.7
1	99	20.0	12	28.6	56	17.4	26	24.8
2 or more	53	10.7	4	9.5	33	10.3	10	9.5
Unknown	14	2.8	0	0.0	7	2.2	0	0.0
Family history of clefts
Maternal
Yes	93	18.8	10	23.8	70	21.8	18	17.1
No	361	73.1	31	73.8	228	71.0	85	81.0
Unknown	40	8.1	1	2.4	23	7.2	2	1.9
Paternal
Yes	94	19.0	3	7.1	45	14.0	12	11.4
No	313	63.4	28	66.7	224	69.8	78	74.3
Unknown	87	17.6	11	25.2	52	16.2	15	14.3
Marital status
Married	386	78.1	33	78.6	239	74.4	75	71.4
Living with partner	27	5.5	0	0.0	29	9.0	14	13.3
Single/divorced/separated/widowed	68	13.8	9	21.4	49	15.3	16	15.2
Unknown	13	2.6	0	0.0	4	1.3	0	0.0

^*Year of birth was significantly different in the isolated versus the not isolated cases in both the CLP and CPO groups.