Maternal smoking during pregnancy and risk of phacomatoses: results from a Swedish register-based study

Figures & data

Table 1 Descriptive characteristics and number of phacomatosis cases

	Individuals, n (%)	Phacomatoses de novo/familial	Neurofibromatosis de novo/familial	Phacomatoses excluding neurofibromatosis de novo/familial	Tuberous sclerosis de novo/familial	Sturge–Weber syndrome de novo/Familial	Other phacomatoses^a de novo/familial
Maternal smoking during pregnancy
Non-smoker	2,633,407 (84.1)	1277/437	792/368	485/69	245/28	60/0	240/41
1–9 cig/day	325,059 (10.4)	157/61	105/54	52/7	24/5	8/0	20/2
10+ cig/day	173,590 (5.5)	112/30	60/26	52/4	24/0	7/0	21/4
Parity
0	1,313,256 (41.9)	639/215	388/179	251/36	120/14	28/0	103/22
1	1,140,983 (36.4)	572/188	366/159	206/29	110/12	29/0	67/17
2+	677,817 (21.6)	335/125	203/110	132/15	63/7	18/0	51/8
Maternal age
<20	64,147 (2.0)	37/13	23/13	14/0	6/0	2/0	6/0
20–24	546,122 (17.4)	248/112	142/97	106/15	47/3	15/0	44/12
25–29	1,057,238 (33.8)	516/202	316/173	200/29	86/15	30/0	84/14
30–34	954,191 (30.5)	486/137	297/112	189/25	105/10	17/0	67/15
35–39	426,069 (13.6)	210/56	144/47	66/9	39/5	11/0	16/4
40+	84,289 (2.7)	49/8	35/6	14/2	10/0	0/0	4/2
Paternal age
<20	16,970 (0.5)	11/1	8/1	3/0	1/0	1/0	1/0
20–24	270,318 (8.6)	117/50	70/47	47/3	19/0	7/0	21/3
25–29	834,432 (26.6)	368/163	224/136	144/27	72/13	14/0	58/14
30–34	1,023,284 (32.7)	489/168	285/142	204/26	100/11	27/0	77/15
35–39	629,893 (20.1)	327/92	212/80	115/12	60/7	17/0	38/5
40+	357,159 (11.4)	234/54	158/42	76/12	41/2	9/0	26/10
Birth year
1982–1989	699,945 (22.4)	392/114	255/99	137/15	66/4	14/0	57/11
1990–1999	979,550 (31.3)	555/156	337/123	218/33	118/11	23/0	77/22
2000–2009	925,109 (29.5)	460/180	287/152	173/28	83/14	23/0	67/14
2010–2015	527,452 (16.8)	139/78	78/74	61/4	26/4	15/0	20/0

Note: ^aExcluding neurofibromatosis, tuberous sclerosis, and Sturge–Weber syndrome.

Table 2 Effect of smoking during pregnancy on the risk of de novo and familial phacomatoses

	De novo cases		Familial cases
	N cases	Adjusted OR (95% CI)	N cases	Adjusted OR (95% CI)
All phacomatoses
No smoker	1277	1.0 (ref)	437	1.0 (ref)
1–9 cig/day	157	0.93 (0.79–1.11)	61	1.09 (0.83–1.43)
10+ cig/day	112	1.21 (0.99–1.48)	30	1.02 (0.70–1.48)
Neurofibromatosis
No smoker	792	1.0 (ref)	368	1.0 (ref)
1–9 cig/day	105	1.00 (0.81–1.23)	54	1.14 (0.85–1.53)
10+ cig/day	60	1.03 (0.79–1.35)	26	1.04 (0.69–1.56)
Phacomatoses excluding neurofibromatosis
No smoker	485	1.0 (ref)	69	1.0 (ref)
1–9 cig/day	52	0.82 (0.62–1.10)	7	0.83 (0.38–1.82)
10+ cig/day	52	1.51 (1.13–2.03)	4	0.88 (0.32–2.45)
Tuberous sclerosis
No smoker	245	1.0 (ref)	28	1.0 (ref)
1–9 cig/day	24	0.76 (0.50–1.17)	5	1.83 (0.69–4.84)
10+ cig/day	24	1.39 (0.91–2.14)	0	–
Sturge–Weber syndrome
No smoker	60	1.0 (ref)	0	–
1–9 cig/day	8	1.11 (0.52–2.35)	0	–
10+ cig/day	7	1.86 (0.83–4.19)	0	–
Other phacomatoses^a
No smoker	180	1.0 (ref)	41	1.0 (ref)
1–9 cig/day	20	0.81 (0.51–1.30)	2	0.35 (0.08–1.44)
10+ cig/day	21	1.57 (0.99–2.50)	4	1.25 (0.44–3.57)

Notes: Adjusted for maternal age, paternal age, birth cohort, and parity. ^aExcluding neurofibromatosis, tuberous sclerosis, and Sturge–Weber syndrome.